This method is called when {@link //singleTokenDeletion} identifies -// single-token deletion as a viable recovery strategy for a mismatched -// input error.
-// -//The default implementation simply returns if the handler is already in -// error recovery mode. Otherwise, it calls {@link //beginErrorCondition} to -// enter error recovery mode, followed by calling -// {@link Parser//NotifyErrorListeners}.
-// -// @param recognizer the parser instance -func (d *DefaultErrorStrategy) ReportUnwantedToken(recognizer Parser) { - if d.InErrorRecoveryMode(recognizer) { - return - } - d.beginErrorCondition(recognizer) - t := recognizer.GetCurrentToken() - tokenName := d.GetTokenErrorDisplay(t) - expecting := d.GetExpectedTokens(recognizer) - msg := "extraneous input " + tokenName + " expecting " + - expecting.StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false) - recognizer.NotifyErrorListeners(msg, t, nil) -} - -// This method is called to Report a syntax error which requires the -// insertion of a missing token into the input stream. At the time d -// method is called, the missing token has not yet been inserted. When d -// method returns, {@code recognizer} is in error recovery mode. -// -//This method is called when {@link //singleTokenInsertion} identifies -// single-token insertion as a viable recovery strategy for a mismatched -// input error.
-// -//The default implementation simply returns if the handler is already in -// error recovery mode. Otherwise, it calls {@link //beginErrorCondition} to -// enter error recovery mode, followed by calling -// {@link Parser//NotifyErrorListeners}.
-// -// @param recognizer the parser instance -func (d *DefaultErrorStrategy) ReportMissingToken(recognizer Parser) { - if d.InErrorRecoveryMode(recognizer) { - return - } - d.beginErrorCondition(recognizer) - t := recognizer.GetCurrentToken() - expecting := d.GetExpectedTokens(recognizer) - msg := "missing " + expecting.StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false) + - " at " + d.GetTokenErrorDisplay(t) - recognizer.NotifyErrorListeners(msg, t, nil) -} - -//The default implementation attempts to recover from the mismatched input -// by using single token insertion and deletion as described below. If the -// recovery attempt fails, d method panics an -// {@link InputMisMatchException}.
-// -//EXTRA TOKEN (single token deletion)
-// -//{@code LA(1)} is not what we are looking for. If {@code LA(2)} has the -// right token, however, then assume {@code LA(1)} is some extra spurious -// token and delete it. Then consume and return the next token (which was -// the {@code LA(2)} token) as the successful result of the Match operation.
-// -//This recovery strategy is implemented by {@link -// //singleTokenDeletion}.
-// -//MISSING TOKEN (single token insertion)
-// -//If current token (at {@code LA(1)}) is consistent with what could come -// after the expected {@code LA(1)} token, then assume the token is missing -// and use the parser's {@link TokenFactory} to create it on the fly. The -// "insertion" is performed by returning the created token as the successful -// result of the Match operation.
-// -//This recovery strategy is implemented by {@link -// //singleTokenInsertion}.
-// -//EXAMPLE
-// -//For example, Input {@code i=(3} is clearly missing the {@code ')'}. When -// the parser returns from the nested call to {@code expr}, it will have -// call chain:
-// -//-// stat &rarr expr &rarr atom -//-// -// and it will be trying to Match the {@code ')'} at d point in the -// derivation: -// -//
-// => ID '=' '(' INT ')' ('+' atom)* ”
-// ^
-//
-//
-// The attempt to Match {@code ')'} will fail when it sees {@code ”} and
-// call {@link //recoverInline}. To recover, it sees that {@code LA(1)==”}
-// is in the set of tokens that can follow the {@code ')'} token reference
-// in rule {@code atom}. It can assume that you forgot the {@code ')'}.
-func (d *DefaultErrorStrategy) RecoverInline(recognizer Parser) Token {
- // SINGLE TOKEN DELETION
- MatchedSymbol := d.SingleTokenDeletion(recognizer)
- if MatchedSymbol != nil {
- // we have deleted the extra token.
- // now, move past ttype token as if all were ok
- recognizer.Consume()
- return MatchedSymbol
- }
- // SINGLE TOKEN INSERTION
- if d.SingleTokenInsertion(recognizer) {
- return d.GetMissingSymbol(recognizer)
- }
- // even that didn't work must panic the exception
- panic(NewInputMisMatchException(recognizer))
-}
-
-// This method implements the single-token insertion inline error recovery
-// strategy. It is called by {@link //recoverInline} if the single-token
-// deletion strategy fails to recover from the mismatched input. If this
-// method returns {@code true}, {@code recognizer} will be in error recovery
-// mode.
-//
-// This method determines whether or not single-token insertion is viable by -// checking if the {@code LA(1)} input symbol could be successfully Matched -// if it were instead the {@code LA(2)} symbol. If d method returns -// {@code true}, the caller is responsible for creating and inserting a -// token with the correct type to produce d behavior.
-// -// @param recognizer the parser instance -// @return {@code true} if single-token insertion is a viable recovery -// strategy for the current mismatched input, otherwise {@code false} -func (d *DefaultErrorStrategy) SingleTokenInsertion(recognizer Parser) bool { - currentSymbolType := recognizer.GetTokenStream().LA(1) - // if current token is consistent with what could come after current - // ATN state, then we know we're missing a token error recovery - // is free to conjure up and insert the missing token - atn := recognizer.GetInterpreter().atn - currentState := atn.states[recognizer.GetState()] - next := currentState.GetTransitions()[0].getTarget() - expectingAtLL2 := atn.NextTokens(next, recognizer.GetParserRuleContext()) - if expectingAtLL2.contains(currentSymbolType) { - d.ReportMissingToken(recognizer) - return true - } - - return false -} - -// This method implements the single-token deletion inline error recovery -// strategy. It is called by {@link //recoverInline} to attempt to recover -// from mismatched input. If this method returns nil, the parser and error -// handler state will not have changed. If this method returns non-nil, -// {@code recognizer} will not be in error recovery mode since the -// returned token was a successful Match. -// -//If the single-token deletion is successful, d method calls -// {@link //ReportUnwantedToken} to Report the error, followed by -// {@link Parser//consume} to actually "delete" the extraneous token. Then, -// before returning {@link //ReportMatch} is called to signal a successful -// Match.
-// -// @param recognizer the parser instance -// @return the successfully Matched {@link Token} instance if single-token -// deletion successfully recovers from the mismatched input, otherwise -// {@code nil} -func (d *DefaultErrorStrategy) SingleTokenDeletion(recognizer Parser) Token { - NextTokenType := recognizer.GetTokenStream().LA(2) - expecting := d.GetExpectedTokens(recognizer) - if expecting.contains(NextTokenType) { - d.ReportUnwantedToken(recognizer) - // print("recoverFromMisMatchedToken deleting " \ - // + str(recognizer.GetTokenStream().LT(1)) \ - // + " since " + str(recognizer.GetTokenStream().LT(2)) \ - // + " is what we want", file=sys.stderr) - recognizer.Consume() // simply delete extra token - // we want to return the token we're actually Matching - MatchedSymbol := recognizer.GetCurrentToken() - d.ReportMatch(recognizer) // we know current token is correct - return MatchedSymbol - } - - return nil -} - -// Conjure up a missing token during error recovery. -// -// The recognizer attempts to recover from single missing -// symbols. But, actions might refer to that missing symbol. -// For example, x=ID {f($x)}. The action clearly assumes -// that there has been an identifier Matched previously and that -// $x points at that token. If that token is missing, but -// the next token in the stream is what we want we assume that -// d token is missing and we keep going. Because we -// have to return some token to replace the missing token, -// we have to conjure one up. This method gives the user control -// over the tokens returned for missing tokens. Mostly, -// you will want to create something special for identifier -// tokens. For literals such as '{' and ',', the default -// action in the parser or tree parser works. It simply creates -// a CommonToken of the appropriate type. The text will be the token. -// If you change what tokens must be created by the lexer, -// override d method to create the appropriate tokens. -func (d *DefaultErrorStrategy) GetMissingSymbol(recognizer Parser) Token { - currentSymbol := recognizer.GetCurrentToken() - expecting := d.GetExpectedTokens(recognizer) - expectedTokenType := expecting.first() - var tokenText string - - if expectedTokenType == TokenEOF { - tokenText = "-// This error strategy is useful in the following scenarios.
-// -//-
-//
- Two-stage parsing: This error strategy allows the first -// stage of two-stage parsing to immediately terminate if an error is -// encountered, and immediately fall back to the second stage. In addition to -// avoiding wasted work by attempting to recover from errors here, the empty -// implementation of {@link BailErrorStrategy//Sync} improves the performance of -// the first stage. -//
- Silent validation: When syntax errors are not being -// Reported or logged, and the parse result is simply ignored if errors occur, -// the {@link BailErrorStrategy} avoids wasting work on recovering from errors -// when the result will be ignored either way. -//
-// {@code myparser.setErrorHandler(NewBailErrorStrategy())}
-// -// @see Parser//setErrorHandler(ANTLRErrorStrategy) - -type BailErrorStrategy struct { - *DefaultErrorStrategy -} - -var _ ErrorStrategy = &BailErrorStrategy{} - -func NewBailErrorStrategy() *BailErrorStrategy { - - b := new(BailErrorStrategy) - - b.DefaultErrorStrategy = NewDefaultErrorStrategy() - - return b -} - -// Instead of recovering from exception {@code e}, re-panic it wrapped -// in a {@link ParseCancellationException} so it is not caught by the -// rule func catches. Use {@link Exception//getCause()} to get the -// original {@link RecognitionException}. -func (b *BailErrorStrategy) Recover(recognizer Parser, e RecognitionException) { - context := recognizer.GetParserRuleContext() - for context != nil { - context.SetException(e) - if parent, ok := context.GetParent().(ParserRuleContext); ok { - context = parent - } else { - context = nil - } - } - panic(NewParseCancellationException()) // TODO we don't emit e properly -} - -// Make sure we don't attempt to recover inline if the parser -// successfully recovers, it won't panic an exception. -func (b *BailErrorStrategy) RecoverInline(recognizer Parser) Token { - b.Recover(recognizer, NewInputMisMatchException(recognizer)) - - return nil -} - -// Make sure we don't attempt to recover from problems in subrules.// -func (b *BailErrorStrategy) Sync(recognizer Parser) { - // pass -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "fmt" + "reflect" + "strconv" + "strings" +) + +type ErrorStrategy interface { + reset(Parser) + RecoverInline(Parser) Token + Recover(Parser, RecognitionException) + Sync(Parser) + InErrorRecoveryMode(Parser) bool + ReportError(Parser, RecognitionException) + ReportMatch(Parser) +} + +// This is the default implementation of {@link ANTLRErrorStrategy} used for +// error Reporting and recovery in ANTLR parsers. +type DefaultErrorStrategy struct { + errorRecoveryMode bool + lastErrorIndex int + lastErrorStates *IntervalSet +} + +var _ ErrorStrategy = &DefaultErrorStrategy{} + +func NewDefaultErrorStrategy() *DefaultErrorStrategy { + + d := new(DefaultErrorStrategy) + + // Indicates whether the error strategy is currently "recovering from an + // error". This is used to suppress Reporting multiple error messages while + // attempting to recover from a detected syntax error. + // + // @see //InErrorRecoveryMode + // + d.errorRecoveryMode = false + + // The index into the input stream where the last error occurred. + // This is used to prevent infinite loops where an error is found + // but no token is consumed during recovery...another error is found, + // ad nauseum. This is a failsafe mechanism to guarantee that at least + // one token/tree node is consumed for two errors. + // + d.lastErrorIndex = -1 + d.lastErrorStates = nil + return d +} + +//The default implementation simply calls {@link //endErrorCondition} to +// ensure that the handler is not in error recovery mode.
+func (d *DefaultErrorStrategy) reset(recognizer Parser) { + d.endErrorCondition(recognizer) +} + +// This method is called to enter error recovery mode when a recognition +// exception is Reported. +// +// @param recognizer the parser instance +func (d *DefaultErrorStrategy) beginErrorCondition(recognizer Parser) { + d.errorRecoveryMode = true +} + +func (d *DefaultErrorStrategy) InErrorRecoveryMode(recognizer Parser) bool { + return d.errorRecoveryMode +} + +// This method is called to leave error recovery mode after recovering from +// a recognition exception. +// +// @param recognizer +func (d *DefaultErrorStrategy) endErrorCondition(recognizer Parser) { + d.errorRecoveryMode = false + d.lastErrorStates = nil + d.lastErrorIndex = -1 +} + +// {@inheritDoc} +// +//The default implementation simply calls {@link //endErrorCondition}.
+func (d *DefaultErrorStrategy) ReportMatch(recognizer Parser) { + d.endErrorCondition(recognizer) +} + +// {@inheritDoc} +// +//The default implementation returns immediately if the handler is already +// in error recovery mode. Otherwise, it calls {@link //beginErrorCondition} +// and dispatches the Reporting task based on the runtime type of {@code e} +// according to the following table.
+// +//-
+//
- {@link NoViableAltException}: Dispatches the call to +// {@link //ReportNoViableAlternative} +//
- {@link InputMisMatchException}: Dispatches the call to +// {@link //ReportInputMisMatch} +//
- {@link FailedPredicateException}: Dispatches the call to +// {@link //ReportFailedPredicate} +//
- All other types: calls {@link Parser//NotifyErrorListeners} to Report +// the exception +//
The default implementation reSynchronizes the parser by consuming tokens +// until we find one in the reSynchronization set--loosely the set of tokens +// that can follow the current rule.
+func (d *DefaultErrorStrategy) Recover(recognizer Parser, e RecognitionException) { + + if d.lastErrorIndex == recognizer.GetInputStream().Index() && + d.lastErrorStates != nil && d.lastErrorStates.contains(recognizer.GetState()) { + // uh oh, another error at same token index and previously-Visited + // state in ATN must be a case where LT(1) is in the recovery + // token set so nothing got consumed. Consume a single token + // at least to prevent an infinite loop d is a failsafe. + recognizer.Consume() + } + d.lastErrorIndex = recognizer.GetInputStream().Index() + if d.lastErrorStates == nil { + d.lastErrorStates = NewIntervalSet() + } + d.lastErrorStates.addOne(recognizer.GetState()) + followSet := d.getErrorRecoverySet(recognizer) + d.consumeUntil(recognizer, followSet) +} + +// The default implementation of {@link ANTLRErrorStrategy//Sync} makes sure +// that the current lookahead symbol is consistent with what were expecting +// at d point in the ATN. You can call d anytime but ANTLR only +// generates code to check before subrules/loops and each iteration. +// +//Implements Jim Idle's magic Sync mechanism in closures and optional +// subrules. E.g.,
+// +//
+// a : Sync ( stuff Sync )*
+// Sync : {consume to what can follow Sync}
+//
+//
+// At the start of a sub rule upon error, {@link //Sync} performs single
+// token deletion, if possible. If it can't do that, it bails on the current
+// rule and uses the default error recovery, which consumes until the
+// reSynchronization set of the current rule.
+//
+// If the sub rule is optional ({@code (...)?}, {@code (...)*}, or block +// with an empty alternative), then the expected set includes what follows +// the subrule.
+// +//During loop iteration, it consumes until it sees a token that can start a +// sub rule or what follows loop. Yes, that is pretty aggressive. We opt to +// stay in the loop as long as possible.
+// +//ORIGINS
+// +//Previous versions of ANTLR did a poor job of their recovery within loops. +// A single mismatch token or missing token would force the parser to bail +// out of the entire rules surrounding the loop. So, for rule
+// +//
+// classfunc : 'class' ID '{' member* '}'
+//
+//
+// input with an extra token between members would force the parser to
+// consume until it found the next class definition rather than the next
+// member definition of the current class.
+//
+// This functionality cost a little bit of effort because the parser has to +// compare token set at the start of the loop and at each iteration. If for +// some reason speed is suffering for you, you can turn off d +// functionality by simply overriding d method as a blank { }.
+func (d *DefaultErrorStrategy) Sync(recognizer Parser) { + // If already recovering, don't try to Sync + if d.InErrorRecoveryMode(recognizer) { + return + } + + s := recognizer.GetInterpreter().atn.states[recognizer.GetState()] + la := recognizer.GetTokenStream().LA(1) + + // try cheaper subset first might get lucky. seems to shave a wee bit off + nextTokens := recognizer.GetATN().NextTokens(s, nil) + if nextTokens.contains(TokenEpsilon) || nextTokens.contains(la) { + return + } + + switch s.GetStateType() { + case ATNStateBlockStart, ATNStateStarBlockStart, ATNStatePlusBlockStart, ATNStateStarLoopEntry: + // Report error and recover if possible + if d.SingleTokenDeletion(recognizer) != nil { + return + } + panic(NewInputMisMatchException(recognizer)) + case ATNStatePlusLoopBack, ATNStateStarLoopBack: + d.ReportUnwantedToken(recognizer) + expecting := NewIntervalSet() + expecting.addSet(recognizer.GetExpectedTokens()) + whatFollowsLoopIterationOrRule := expecting.addSet(d.getErrorRecoverySet(recognizer)) + d.consumeUntil(recognizer, whatFollowsLoopIterationOrRule) + default: + // do nothing if we can't identify the exact kind of ATN state + } +} + +// This is called by {@link //ReportError} when the exception is a +// {@link NoViableAltException}. +// +// @see //ReportError +// +// @param recognizer the parser instance +// @param e the recognition exception +func (d *DefaultErrorStrategy) ReportNoViableAlternative(recognizer Parser, e *NoViableAltException) { + tokens := recognizer.GetTokenStream() + var input string + if tokens != nil { + if e.startToken.GetTokenType() == TokenEOF { + input = "This method is called when {@link //singleTokenDeletion} identifies +// single-token deletion as a viable recovery strategy for a mismatched +// input error.
+// +//The default implementation simply returns if the handler is already in +// error recovery mode. Otherwise, it calls {@link //beginErrorCondition} to +// enter error recovery mode, followed by calling +// {@link Parser//NotifyErrorListeners}.
+// +// @param recognizer the parser instance +func (d *DefaultErrorStrategy) ReportUnwantedToken(recognizer Parser) { + if d.InErrorRecoveryMode(recognizer) { + return + } + d.beginErrorCondition(recognizer) + t := recognizer.GetCurrentToken() + tokenName := d.GetTokenErrorDisplay(t) + expecting := d.GetExpectedTokens(recognizer) + msg := "extraneous input " + tokenName + " expecting " + + expecting.StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false) + recognizer.NotifyErrorListeners(msg, t, nil) +} + +// This method is called to Report a syntax error which requires the +// insertion of a missing token into the input stream. At the time d +// method is called, the missing token has not yet been inserted. When d +// method returns, {@code recognizer} is in error recovery mode. +// +//This method is called when {@link //singleTokenInsertion} identifies +// single-token insertion as a viable recovery strategy for a mismatched +// input error.
+// +//The default implementation simply returns if the handler is already in +// error recovery mode. Otherwise, it calls {@link //beginErrorCondition} to +// enter error recovery mode, followed by calling +// {@link Parser//NotifyErrorListeners}.
+// +// @param recognizer the parser instance +func (d *DefaultErrorStrategy) ReportMissingToken(recognizer Parser) { + if d.InErrorRecoveryMode(recognizer) { + return + } + d.beginErrorCondition(recognizer) + t := recognizer.GetCurrentToken() + expecting := d.GetExpectedTokens(recognizer) + msg := "missing " + expecting.StringVerbose(recognizer.GetLiteralNames(), recognizer.GetSymbolicNames(), false) + + " at " + d.GetTokenErrorDisplay(t) + recognizer.NotifyErrorListeners(msg, t, nil) +} + +//The default implementation attempts to recover from the mismatched input +// by using single token insertion and deletion as described below. If the +// recovery attempt fails, d method panics an +// {@link InputMisMatchException}.
+// +//EXTRA TOKEN (single token deletion)
+// +//{@code LA(1)} is not what we are looking for. If {@code LA(2)} has the +// right token, however, then assume {@code LA(1)} is some extra spurious +// token and delete it. Then consume and return the next token (which was +// the {@code LA(2)} token) as the successful result of the Match operation.
+// +//This recovery strategy is implemented by {@link +// //singleTokenDeletion}.
+// +//MISSING TOKEN (single token insertion)
+// +//If current token (at {@code LA(1)}) is consistent with what could come +// after the expected {@code LA(1)} token, then assume the token is missing +// and use the parser's {@link TokenFactory} to create it on the fly. The +// "insertion" is performed by returning the created token as the successful +// result of the Match operation.
+// +//This recovery strategy is implemented by {@link +// //singleTokenInsertion}.
+// +//EXAMPLE
+// +//For example, Input {@code i=(3} is clearly missing the {@code ')'}. When +// the parser returns from the nested call to {@code expr}, it will have +// call chain:
+// +//+// stat &rarr expr &rarr atom +//+// +// and it will be trying to Match the {@code ')'} at d point in the +// derivation: +// +//
+// => ID '=' '(' INT ')' ('+' atom)* ”
+// ^
+//
+//
+// The attempt to Match {@code ')'} will fail when it sees {@code ”} and
+// call {@link //recoverInline}. To recover, it sees that {@code LA(1)==”}
+// is in the set of tokens that can follow the {@code ')'} token reference
+// in rule {@code atom}. It can assume that you forgot the {@code ')'}.
+func (d *DefaultErrorStrategy) RecoverInline(recognizer Parser) Token {
+ // SINGLE TOKEN DELETION
+ MatchedSymbol := d.SingleTokenDeletion(recognizer)
+ if MatchedSymbol != nil {
+ // we have deleted the extra token.
+ // now, move past ttype token as if all were ok
+ recognizer.Consume()
+ return MatchedSymbol
+ }
+ // SINGLE TOKEN INSERTION
+ if d.SingleTokenInsertion(recognizer) {
+ return d.GetMissingSymbol(recognizer)
+ }
+ // even that didn't work must panic the exception
+ panic(NewInputMisMatchException(recognizer))
+}
+
+// This method implements the single-token insertion inline error recovery
+// strategy. It is called by {@link //recoverInline} if the single-token
+// deletion strategy fails to recover from the mismatched input. If this
+// method returns {@code true}, {@code recognizer} will be in error recovery
+// mode.
+//
+// This method determines whether or not single-token insertion is viable by +// checking if the {@code LA(1)} input symbol could be successfully Matched +// if it were instead the {@code LA(2)} symbol. If d method returns +// {@code true}, the caller is responsible for creating and inserting a +// token with the correct type to produce d behavior.
+// +// @param recognizer the parser instance +// @return {@code true} if single-token insertion is a viable recovery +// strategy for the current mismatched input, otherwise {@code false} +func (d *DefaultErrorStrategy) SingleTokenInsertion(recognizer Parser) bool { + currentSymbolType := recognizer.GetTokenStream().LA(1) + // if current token is consistent with what could come after current + // ATN state, then we know we're missing a token error recovery + // is free to conjure up and insert the missing token + atn := recognizer.GetInterpreter().atn + currentState := atn.states[recognizer.GetState()] + next := currentState.GetTransitions()[0].getTarget() + expectingAtLL2 := atn.NextTokens(next, recognizer.GetParserRuleContext()) + if expectingAtLL2.contains(currentSymbolType) { + d.ReportMissingToken(recognizer) + return true + } + + return false +} + +// This method implements the single-token deletion inline error recovery +// strategy. It is called by {@link //recoverInline} to attempt to recover +// from mismatched input. If this method returns nil, the parser and error +// handler state will not have changed. If this method returns non-nil, +// {@code recognizer} will not be in error recovery mode since the +// returned token was a successful Match. +// +//If the single-token deletion is successful, d method calls +// {@link //ReportUnwantedToken} to Report the error, followed by +// {@link Parser//consume} to actually "delete" the extraneous token. Then, +// before returning {@link //ReportMatch} is called to signal a successful +// Match.
+// +// @param recognizer the parser instance +// @return the successfully Matched {@link Token} instance if single-token +// deletion successfully recovers from the mismatched input, otherwise +// {@code nil} +func (d *DefaultErrorStrategy) SingleTokenDeletion(recognizer Parser) Token { + NextTokenType := recognizer.GetTokenStream().LA(2) + expecting := d.GetExpectedTokens(recognizer) + if expecting.contains(NextTokenType) { + d.ReportUnwantedToken(recognizer) + // print("recoverFromMisMatchedToken deleting " \ + // + str(recognizer.GetTokenStream().LT(1)) \ + // + " since " + str(recognizer.GetTokenStream().LT(2)) \ + // + " is what we want", file=sys.stderr) + recognizer.Consume() // simply delete extra token + // we want to return the token we're actually Matching + MatchedSymbol := recognizer.GetCurrentToken() + d.ReportMatch(recognizer) // we know current token is correct + return MatchedSymbol + } + + return nil +} + +// Conjure up a missing token during error recovery. +// +// The recognizer attempts to recover from single missing +// symbols. But, actions might refer to that missing symbol. +// For example, x=ID {f($x)}. The action clearly assumes +// that there has been an identifier Matched previously and that +// $x points at that token. If that token is missing, but +// the next token in the stream is what we want we assume that +// d token is missing and we keep going. Because we +// have to return some token to replace the missing token, +// we have to conjure one up. This method gives the user control +// over the tokens returned for missing tokens. Mostly, +// you will want to create something special for identifier +// tokens. For literals such as '{' and ',', the default +// action in the parser or tree parser works. It simply creates +// a CommonToken of the appropriate type. The text will be the token. +// If you change what tokens must be created by the lexer, +// override d method to create the appropriate tokens. +func (d *DefaultErrorStrategy) GetMissingSymbol(recognizer Parser) Token { + currentSymbol := recognizer.GetCurrentToken() + expecting := d.GetExpectedTokens(recognizer) + expectedTokenType := expecting.first() + var tokenText string + + if expectedTokenType == TokenEOF { + tokenText = "+// This error strategy is useful in the following scenarios.
+// +//-
+//
- Two-stage parsing: This error strategy allows the first +// stage of two-stage parsing to immediately terminate if an error is +// encountered, and immediately fall back to the second stage. In addition to +// avoiding wasted work by attempting to recover from errors here, the empty +// implementation of {@link BailErrorStrategy//Sync} improves the performance of +// the first stage. +//
- Silent validation: When syntax errors are not being +// Reported or logged, and the parse result is simply ignored if errors occur, +// the {@link BailErrorStrategy} avoids wasting work on recovering from errors +// when the result will be ignored either way. +//
+// {@code myparser.setErrorHandler(NewBailErrorStrategy())}
+// +// @see Parser//setErrorHandler(ANTLRErrorStrategy) + +type BailErrorStrategy struct { + *DefaultErrorStrategy +} + +var _ ErrorStrategy = &BailErrorStrategy{} + +func NewBailErrorStrategy() *BailErrorStrategy { + + b := new(BailErrorStrategy) + + b.DefaultErrorStrategy = NewDefaultErrorStrategy() + + return b +} + +// Instead of recovering from exception {@code e}, re-panic it wrapped +// in a {@link ParseCancellationException} so it is not caught by the +// rule func catches. Use {@link Exception//getCause()} to get the +// original {@link RecognitionException}. +func (b *BailErrorStrategy) Recover(recognizer Parser, e RecognitionException) { + context := recognizer.GetParserRuleContext() + for context != nil { + context.SetException(e) + if parent, ok := context.GetParent().(ParserRuleContext); ok { + context = parent + } else { + context = nil + } + } + panic(NewParseCancellationException()) // TODO we don't emit e properly +} + +// Make sure we don't attempt to recover inline if the parser +// successfully recovers, it won't panic an exception. +func (b *BailErrorStrategy) RecoverInline(recognizer Parser) Token { + b.Recover(recognizer, NewInputMisMatchException(recognizer)) + + return nil +} + +// Make sure we don't attempt to recover from problems in subrules.// +func (b *BailErrorStrategy) Sync(recognizer Parser) { + // pass +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/errors.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/errors.go index 3954c13782..acba949e18 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/errors.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/errors.go @@ -1,238 +1,238 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -// The root of the ANTLR exception hierarchy. In general, ANTLR tracks just -// 3 kinds of errors: prediction errors, failed predicate errors, and -// mismatched input errors. In each case, the parser knows where it is -// in the input, where it is in the ATN, the rule invocation stack, -// and what kind of problem occurred. - -type RecognitionException interface { - GetOffendingToken() Token - GetMessage() string - GetInputStream() IntStream -} - -type BaseRecognitionException struct { - message string - recognizer Recognizer - offendingToken Token - offendingState int - ctx RuleContext - input IntStream -} - -func NewBaseRecognitionException(message string, recognizer Recognizer, input IntStream, ctx RuleContext) *BaseRecognitionException { - - // todo - // Error.call(this) - // - // if (!!Error.captureStackTrace) { - // Error.captureStackTrace(this, RecognitionException) - // } else { - // stack := NewError().stack - // } - // TODO may be able to use - "runtime" func Stack(buf []byte, all bool) int - - t := new(BaseRecognitionException) - - t.message = message - t.recognizer = recognizer - t.input = input - t.ctx = ctx - // The current {@link Token} when an error occurred. Since not all streams - // support accessing symbols by index, we have to track the {@link Token} - // instance itself. - t.offendingToken = nil - // Get the ATN state number the parser was in at the time the error - // occurred. For {@link NoViableAltException} and - // {@link LexerNoViableAltException} exceptions, this is the - // {@link DecisionState} number. For others, it is the state whose outgoing - // edge we couldn't Match. - t.offendingState = -1 - if t.recognizer != nil { - t.offendingState = t.recognizer.GetState() - } - - return t -} - -func (b *BaseRecognitionException) GetMessage() string { - return b.message -} - -func (b *BaseRecognitionException) GetOffendingToken() Token { - return b.offendingToken -} - -func (b *BaseRecognitionException) GetInputStream() IntStream { - return b.input -} - -//If the state number is not known, b method returns -1.
- -// Gets the set of input symbols which could potentially follow the -// previously Matched symbol at the time b exception was panicn. -// -//If the set of expected tokens is not known and could not be computed, -// b method returns {@code nil}.
-// -// @return The set of token types that could potentially follow the current -// state in the ATN, or {@code nil} if the information is not available. -// / -func (b *BaseRecognitionException) getExpectedTokens() *IntervalSet { - if b.recognizer != nil { - return b.recognizer.GetATN().getExpectedTokens(b.offendingState, b.ctx) - } - - return nil -} - -func (b *BaseRecognitionException) String() string { - return b.message -} - -type LexerNoViableAltException struct { - *BaseRecognitionException - - startIndex int - deadEndConfigs ATNConfigSet -} - -func NewLexerNoViableAltException(lexer Lexer, input CharStream, startIndex int, deadEndConfigs ATNConfigSet) *LexerNoViableAltException { - - l := new(LexerNoViableAltException) - - l.BaseRecognitionException = NewBaseRecognitionException("", lexer, input, nil) - - l.startIndex = startIndex - l.deadEndConfigs = deadEndConfigs - - return l -} - -func (l *LexerNoViableAltException) String() string { - symbol := "" - if l.startIndex >= 0 && l.startIndex < l.input.Size() { - symbol = l.input.(CharStream).GetTextFromInterval(NewInterval(l.startIndex, l.startIndex)) - } - return "LexerNoViableAltException" + symbol -} - -type NoViableAltException struct { - *BaseRecognitionException - - startToken Token - offendingToken Token - ctx ParserRuleContext - deadEndConfigs ATNConfigSet -} - -// Indicates that the parser could not decide which of two or more paths -// to take based upon the remaining input. It tracks the starting token -// of the offending input and also knows where the parser was -// in the various paths when the error. Reported by ReportNoViableAlternative() -func NewNoViableAltException(recognizer Parser, input TokenStream, startToken Token, offendingToken Token, deadEndConfigs ATNConfigSet, ctx ParserRuleContext) *NoViableAltException { - - if ctx == nil { - ctx = recognizer.GetParserRuleContext() - } - - if offendingToken == nil { - offendingToken = recognizer.GetCurrentToken() - } - - if startToken == nil { - startToken = recognizer.GetCurrentToken() - } - - if input == nil { - input = recognizer.GetInputStream().(TokenStream) - } - - n := new(NoViableAltException) - n.BaseRecognitionException = NewBaseRecognitionException("", recognizer, input, ctx) - - // Which configurations did we try at input.Index() that couldn't Match - // input.LT(1)?// - n.deadEndConfigs = deadEndConfigs - // The token object at the start index the input stream might - // not be buffering tokens so get a reference to it. (At the - // time the error occurred, of course the stream needs to keep a - // buffer all of the tokens but later we might not have access to those.) - n.startToken = startToken - n.offendingToken = offendingToken - - return n -} - -type InputMisMatchException struct { - *BaseRecognitionException -} - -// This signifies any kind of mismatched input exceptions such as -// when the current input does not Match the expected token. -func NewInputMisMatchException(recognizer Parser) *InputMisMatchException { - - i := new(InputMisMatchException) - i.BaseRecognitionException = NewBaseRecognitionException("", recognizer, recognizer.GetInputStream(), recognizer.GetParserRuleContext()) - - i.offendingToken = recognizer.GetCurrentToken() - - return i - -} - -// A semantic predicate failed during validation. Validation of predicates -// occurs when normally parsing the alternative just like Matching a token. -// Disambiguating predicate evaluation occurs when we test a predicate during -// prediction. - -type FailedPredicateException struct { - *BaseRecognitionException - - ruleIndex int - predicateIndex int - predicate string -} - -func NewFailedPredicateException(recognizer Parser, predicate string, message string) *FailedPredicateException { - - f := new(FailedPredicateException) - - f.BaseRecognitionException = NewBaseRecognitionException(f.formatMessage(predicate, message), recognizer, recognizer.GetInputStream(), recognizer.GetParserRuleContext()) - - s := recognizer.GetInterpreter().atn.states[recognizer.GetState()] - trans := s.GetTransitions()[0] - if trans2, ok := trans.(*PredicateTransition); ok { - f.ruleIndex = trans2.ruleIndex - f.predicateIndex = trans2.predIndex - } else { - f.ruleIndex = 0 - f.predicateIndex = 0 - } - f.predicate = predicate - f.offendingToken = recognizer.GetCurrentToken() - - return f -} - -func (f *FailedPredicateException) formatMessage(predicate, message string) string { - if message != "" { - return message - } - - return "failed predicate: {" + predicate + "}?" -} - -type ParseCancellationException struct { -} - -func NewParseCancellationException() *ParseCancellationException { - // Error.call(this) - // Error.captureStackTrace(this, ParseCancellationException) - return new(ParseCancellationException) -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +// The root of the ANTLR exception hierarchy. In general, ANTLR tracks just +// 3 kinds of errors: prediction errors, failed predicate errors, and +// mismatched input errors. In each case, the parser knows where it is +// in the input, where it is in the ATN, the rule invocation stack, +// and what kind of problem occurred. + +type RecognitionException interface { + GetOffendingToken() Token + GetMessage() string + GetInputStream() IntStream +} + +type BaseRecognitionException struct { + message string + recognizer Recognizer + offendingToken Token + offendingState int + ctx RuleContext + input IntStream +} + +func NewBaseRecognitionException(message string, recognizer Recognizer, input IntStream, ctx RuleContext) *BaseRecognitionException { + + // todo + // Error.call(this) + // + // if (!!Error.captureStackTrace) { + // Error.captureStackTrace(this, RecognitionException) + // } else { + // stack := NewError().stack + // } + // TODO may be able to use - "runtime" func Stack(buf []byte, all bool) int + + t := new(BaseRecognitionException) + + t.message = message + t.recognizer = recognizer + t.input = input + t.ctx = ctx + // The current {@link Token} when an error occurred. Since not all streams + // support accessing symbols by index, we have to track the {@link Token} + // instance itself. + t.offendingToken = nil + // Get the ATN state number the parser was in at the time the error + // occurred. For {@link NoViableAltException} and + // {@link LexerNoViableAltException} exceptions, this is the + // {@link DecisionState} number. For others, it is the state whose outgoing + // edge we couldn't Match. + t.offendingState = -1 + if t.recognizer != nil { + t.offendingState = t.recognizer.GetState() + } + + return t +} + +func (b *BaseRecognitionException) GetMessage() string { + return b.message +} + +func (b *BaseRecognitionException) GetOffendingToken() Token { + return b.offendingToken +} + +func (b *BaseRecognitionException) GetInputStream() IntStream { + return b.input +} + +//If the state number is not known, b method returns -1.
+ +// Gets the set of input symbols which could potentially follow the +// previously Matched symbol at the time b exception was panicn. +// +//If the set of expected tokens is not known and could not be computed, +// b method returns {@code nil}.
+// +// @return The set of token types that could potentially follow the current +// state in the ATN, or {@code nil} if the information is not available. +// / +func (b *BaseRecognitionException) getExpectedTokens() *IntervalSet { + if b.recognizer != nil { + return b.recognizer.GetATN().getExpectedTokens(b.offendingState, b.ctx) + } + + return nil +} + +func (b *BaseRecognitionException) String() string { + return b.message +} + +type LexerNoViableAltException struct { + *BaseRecognitionException + + startIndex int + deadEndConfigs ATNConfigSet +} + +func NewLexerNoViableAltException(lexer Lexer, input CharStream, startIndex int, deadEndConfigs ATNConfigSet) *LexerNoViableAltException { + + l := new(LexerNoViableAltException) + + l.BaseRecognitionException = NewBaseRecognitionException("", lexer, input, nil) + + l.startIndex = startIndex + l.deadEndConfigs = deadEndConfigs + + return l +} + +func (l *LexerNoViableAltException) String() string { + symbol := "" + if l.startIndex >= 0 && l.startIndex < l.input.Size() { + symbol = l.input.(CharStream).GetTextFromInterval(NewInterval(l.startIndex, l.startIndex)) + } + return "LexerNoViableAltException" + symbol +} + +type NoViableAltException struct { + *BaseRecognitionException + + startToken Token + offendingToken Token + ctx ParserRuleContext + deadEndConfigs ATNConfigSet +} + +// Indicates that the parser could not decide which of two or more paths +// to take based upon the remaining input. It tracks the starting token +// of the offending input and also knows where the parser was +// in the various paths when the error. Reported by ReportNoViableAlternative() +func NewNoViableAltException(recognizer Parser, input TokenStream, startToken Token, offendingToken Token, deadEndConfigs ATNConfigSet, ctx ParserRuleContext) *NoViableAltException { + + if ctx == nil { + ctx = recognizer.GetParserRuleContext() + } + + if offendingToken == nil { + offendingToken = recognizer.GetCurrentToken() + } + + if startToken == nil { + startToken = recognizer.GetCurrentToken() + } + + if input == nil { + input = recognizer.GetInputStream().(TokenStream) + } + + n := new(NoViableAltException) + n.BaseRecognitionException = NewBaseRecognitionException("", recognizer, input, ctx) + + // Which configurations did we try at input.Index() that couldn't Match + // input.LT(1)?// + n.deadEndConfigs = deadEndConfigs + // The token object at the start index the input stream might + // not be buffering tokens so get a reference to it. (At the + // time the error occurred, of course the stream needs to keep a + // buffer all of the tokens but later we might not have access to those.) + n.startToken = startToken + n.offendingToken = offendingToken + + return n +} + +type InputMisMatchException struct { + *BaseRecognitionException +} + +// This signifies any kind of mismatched input exceptions such as +// when the current input does not Match the expected token. +func NewInputMisMatchException(recognizer Parser) *InputMisMatchException { + + i := new(InputMisMatchException) + i.BaseRecognitionException = NewBaseRecognitionException("", recognizer, recognizer.GetInputStream(), recognizer.GetParserRuleContext()) + + i.offendingToken = recognizer.GetCurrentToken() + + return i + +} + +// A semantic predicate failed during validation. Validation of predicates +// occurs when normally parsing the alternative just like Matching a token. +// Disambiguating predicate evaluation occurs when we test a predicate during +// prediction. + +type FailedPredicateException struct { + *BaseRecognitionException + + ruleIndex int + predicateIndex int + predicate string +} + +func NewFailedPredicateException(recognizer Parser, predicate string, message string) *FailedPredicateException { + + f := new(FailedPredicateException) + + f.BaseRecognitionException = NewBaseRecognitionException(f.formatMessage(predicate, message), recognizer, recognizer.GetInputStream(), recognizer.GetParserRuleContext()) + + s := recognizer.GetInterpreter().atn.states[recognizer.GetState()] + trans := s.GetTransitions()[0] + if trans2, ok := trans.(*PredicateTransition); ok { + f.ruleIndex = trans2.ruleIndex + f.predicateIndex = trans2.predIndex + } else { + f.ruleIndex = 0 + f.predicateIndex = 0 + } + f.predicate = predicate + f.offendingToken = recognizer.GetCurrentToken() + + return f +} + +func (f *FailedPredicateException) formatMessage(predicate, message string) string { + if message != "" { + return message + } + + return "failed predicate: {" + predicate + "}?" +} + +type ParseCancellationException struct { +} + +func NewParseCancellationException() *ParseCancellationException { + // Error.call(this) + // Error.captureStackTrace(this, ParseCancellationException) + return new(ParseCancellationException) +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/file_stream.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/file_stream.go index bd6ad5efe3..c044270787 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/file_stream.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/file_stream.go @@ -1,49 +1,49 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "bytes" - "io" - "os" -) - -// This is an InputStream that is loaded from a file all at once -// when you construct the object. - -type FileStream struct { - *InputStream - - filename string -} - -func NewFileStream(fileName string) (*FileStream, error) { - - buf := bytes.NewBuffer(nil) - - f, err := os.Open(fileName) - if err != nil { - return nil, err - } - defer f.Close() - _, err = io.Copy(buf, f) - if err != nil { - return nil, err - } - - fs := new(FileStream) - - fs.filename = fileName - s := string(buf.Bytes()) - - fs.InputStream = NewInputStream(s) - - return fs, nil - -} - -func (f *FileStream) GetSourceName() string { - return f.filename -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "bytes" + "io" + "os" +) + +// This is an InputStream that is loaded from a file all at once +// when you construct the object. + +type FileStream struct { + *InputStream + + filename string +} + +func NewFileStream(fileName string) (*FileStream, error) { + + buf := bytes.NewBuffer(nil) + + f, err := os.Open(fileName) + if err != nil { + return nil, err + } + defer f.Close() + _, err = io.Copy(buf, f) + if err != nil { + return nil, err + } + + fs := new(FileStream) + + fs.filename = fileName + s := string(buf.Bytes()) + + fs.InputStream = NewInputStream(s) + + return fs, nil + +} + +func (f *FileStream) GetSourceName() string { + return f.filename +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/input_stream.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/input_stream.go index a8b889cedb..22bd585aa6 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/input_stream.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/input_stream.go @@ -1,113 +1,113 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -type InputStream struct { - name string - index int - data []rune - size int -} - -func NewInputStream(data string) *InputStream { - - is := new(InputStream) - - is.name = "The {@code Skip} command does not have any parameters, so l action is -// implemented as a singleton instance exposed by {@link //INSTANCE}.
-type LexerSkipAction struct { - *BaseLexerAction -} - -func NewLexerSkipAction() *LexerSkipAction { - la := new(LexerSkipAction) - la.BaseLexerAction = NewBaseLexerAction(LexerActionTypeSkip) - return la -} - -// Provides a singleton instance of l parameterless lexer action. -var LexerSkipActionINSTANCE = NewLexerSkipAction() - -func (l *LexerSkipAction) execute(lexer Lexer) { - lexer.Skip() -} - -func (l *LexerSkipAction) String() string { - return "skip" -} - -// Implements the {@code type} lexer action by calling {@link Lexer//setType} -// -// with the assigned type. -type LexerTypeAction struct { - *BaseLexerAction - - thetype int -} - -func NewLexerTypeAction(thetype int) *LexerTypeAction { - l := new(LexerTypeAction) - l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeType) - l.thetype = thetype - return l -} - -func (l *LexerTypeAction) execute(lexer Lexer) { - lexer.SetType(l.thetype) -} - -func (l *LexerTypeAction) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, l.actionType) - h = murmurUpdate(h, l.thetype) - return murmurFinish(h, 2) -} - -func (l *LexerTypeAction) Equals(other LexerAction) bool { - if l == other { - return true - } else if _, ok := other.(*LexerTypeAction); !ok { - return false - } else { - return l.thetype == other.(*LexerTypeAction).thetype - } -} - -func (l *LexerTypeAction) String() string { - return "actionType(" + strconv.Itoa(l.thetype) + ")" -} - -// Implements the {@code pushMode} lexer action by calling -// {@link Lexer//pushMode} with the assigned mode. -type LexerPushModeAction struct { - *BaseLexerAction - - mode int -} - -func NewLexerPushModeAction(mode int) *LexerPushModeAction { - - l := new(LexerPushModeAction) - l.BaseLexerAction = NewBaseLexerAction(LexerActionTypePushMode) - - l.mode = mode - return l -} - -//This action is implemented by calling {@link Lexer//pushMode} with the -// value provided by {@link //getMode}.
-func (l *LexerPushModeAction) execute(lexer Lexer) { - lexer.PushMode(l.mode) -} - -func (l *LexerPushModeAction) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, l.actionType) - h = murmurUpdate(h, l.mode) - return murmurFinish(h, 2) -} - -func (l *LexerPushModeAction) Equals(other LexerAction) bool { - if l == other { - return true - } else if _, ok := other.(*LexerPushModeAction); !ok { - return false - } else { - return l.mode == other.(*LexerPushModeAction).mode - } -} - -func (l *LexerPushModeAction) String() string { - return "pushMode(" + strconv.Itoa(l.mode) + ")" -} - -// Implements the {@code popMode} lexer action by calling {@link Lexer//popMode}. -// -//The {@code popMode} command does not have any parameters, so l action is -// implemented as a singleton instance exposed by {@link //INSTANCE}.
-type LexerPopModeAction struct { - *BaseLexerAction -} - -func NewLexerPopModeAction() *LexerPopModeAction { - - l := new(LexerPopModeAction) - - l.BaseLexerAction = NewBaseLexerAction(LexerActionTypePopMode) - - return l -} - -var LexerPopModeActionINSTANCE = NewLexerPopModeAction() - -//This action is implemented by calling {@link Lexer//popMode}.
-func (l *LexerPopModeAction) execute(lexer Lexer) { - lexer.PopMode() -} - -func (l *LexerPopModeAction) String() string { - return "popMode" -} - -// Implements the {@code more} lexer action by calling {@link Lexer//more}. -// -//The {@code more} command does not have any parameters, so l action is -// implemented as a singleton instance exposed by {@link //INSTANCE}.
- -type LexerMoreAction struct { - *BaseLexerAction -} - -func NewLexerMoreAction() *LexerMoreAction { - l := new(LexerMoreAction) - l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeMore) - - return l -} - -var LexerMoreActionINSTANCE = NewLexerMoreAction() - -//This action is implemented by calling {@link Lexer//popMode}.
-func (l *LexerMoreAction) execute(lexer Lexer) { - lexer.More() -} - -func (l *LexerMoreAction) String() string { - return "more" -} - -// Implements the {@code mode} lexer action by calling {@link Lexer//mode} with -// the assigned mode. -type LexerModeAction struct { - *BaseLexerAction - - mode int -} - -func NewLexerModeAction(mode int) *LexerModeAction { - l := new(LexerModeAction) - l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeMode) - l.mode = mode - return l -} - -//This action is implemented by calling {@link Lexer//mode} with the -// value provided by {@link //getMode}.
-func (l *LexerModeAction) execute(lexer Lexer) { - lexer.SetMode(l.mode) -} - -func (l *LexerModeAction) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, l.actionType) - h = murmurUpdate(h, l.mode) - return murmurFinish(h, 2) -} - -func (l *LexerModeAction) Equals(other LexerAction) bool { - if l == other { - return true - } else if _, ok := other.(*LexerModeAction); !ok { - return false - } else { - return l.mode == other.(*LexerModeAction).mode - } -} - -func (l *LexerModeAction) String() string { - return "mode(" + strconv.Itoa(l.mode) + ")" -} - -// Executes a custom lexer action by calling {@link Recognizer//action} with the -// rule and action indexes assigned to the custom action. The implementation of -// a custom action is added to the generated code for the lexer in an override -// of {@link Recognizer//action} when the grammar is compiled. -// -//This class may represent embedded actions created with the {...}
-// syntax in ANTLR 4, as well as actions created for lexer commands where the
-// command argument could not be evaluated when the grammar was compiled.
Custom actions are implemented by calling {@link Lexer//action} with the -// appropriate rule and action indexes.
-func (l *LexerCustomAction) execute(lexer Lexer) { - lexer.Action(nil, l.ruleIndex, l.actionIndex) -} - -func (l *LexerCustomAction) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, l.actionType) - h = murmurUpdate(h, l.ruleIndex) - h = murmurUpdate(h, l.actionIndex) - return murmurFinish(h, 3) -} - -func (l *LexerCustomAction) Equals(other LexerAction) bool { - if l == other { - return true - } else if _, ok := other.(*LexerCustomAction); !ok { - return false - } else { - return l.ruleIndex == other.(*LexerCustomAction).ruleIndex && - l.actionIndex == other.(*LexerCustomAction).actionIndex - } -} - -// Implements the {@code channel} lexer action by calling -// {@link Lexer//setChannel} with the assigned channel. -// Constructs a New{@code channel} action with the specified channel value. -// @param channel The channel value to pass to {@link Lexer//setChannel}. -type LexerChannelAction struct { - *BaseLexerAction - - channel int -} - -func NewLexerChannelAction(channel int) *LexerChannelAction { - l := new(LexerChannelAction) - l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeChannel) - l.channel = channel - return l -} - -//This action is implemented by calling {@link Lexer//setChannel} with the -// value provided by {@link //getChannel}.
-func (l *LexerChannelAction) execute(lexer Lexer) { - lexer.SetChannel(l.channel) -} - -func (l *LexerChannelAction) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, l.actionType) - h = murmurUpdate(h, l.channel) - return murmurFinish(h, 2) -} - -func (l *LexerChannelAction) Equals(other LexerAction) bool { - if l == other { - return true - } else if _, ok := other.(*LexerChannelAction); !ok { - return false - } else { - return l.channel == other.(*LexerChannelAction).channel - } -} - -func (l *LexerChannelAction) String() string { - return "channel(" + strconv.Itoa(l.channel) + ")" -} - -// This implementation of {@link LexerAction} is used for tracking input offsets -// for position-dependent actions within a {@link LexerActionExecutor}. -// -//This action is not serialized as part of the ATN, and is only required for -// position-dependent lexer actions which appear at a location other than the -// end of a rule. For more information about DFA optimizations employed for -// lexer actions, see {@link LexerActionExecutor//append} and -// {@link LexerActionExecutor//fixOffsetBeforeMatch}.
- -// Constructs a Newindexed custom action by associating a character offset -// with a {@link LexerAction}. -// -//Note: This class is only required for lexer actions for which -// {@link LexerAction//isPositionDependent} returns {@code true}.
-// -// @param offset The offset into the input {@link CharStream}, relative to -// the token start index, at which the specified lexer action should be -// executed. -// @param action The lexer action to execute at a particular offset in the -// input {@link CharStream}. -type LexerIndexedCustomAction struct { - *BaseLexerAction - - offset int - lexerAction LexerAction - isPositionDependent bool -} - -func NewLexerIndexedCustomAction(offset int, lexerAction LexerAction) *LexerIndexedCustomAction { - - l := new(LexerIndexedCustomAction) - l.BaseLexerAction = NewBaseLexerAction(lexerAction.getActionType()) - - l.offset = offset - l.lexerAction = lexerAction - l.isPositionDependent = true - - return l -} - -//This method calls {@link //execute} on the result of {@link //getAction} -// using the provided {@code lexer}.
-func (l *LexerIndexedCustomAction) execute(lexer Lexer) { - // assume the input stream position was properly set by the calling code - l.lexerAction.execute(lexer) -} - -func (l *LexerIndexedCustomAction) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, l.offset) - h = murmurUpdate(h, l.lexerAction.Hash()) - return murmurFinish(h, 2) -} - -func (l *LexerIndexedCustomAction) equals(other LexerAction) bool { - if l == other { - return true - } else if _, ok := other.(*LexerIndexedCustomAction); !ok { - return false - } else { - return l.offset == other.(*LexerIndexedCustomAction).offset && - l.lexerAction.Equals(other.(*LexerIndexedCustomAction).lexerAction) - } -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import "strconv" + +const ( + LexerActionTypeChannel = 0 //The type of a {@link LexerChannelAction} action. + LexerActionTypeCustom = 1 //The type of a {@link LexerCustomAction} action. + LexerActionTypeMode = 2 //The type of a {@link LexerModeAction} action. + LexerActionTypeMore = 3 //The type of a {@link LexerMoreAction} action. + LexerActionTypePopMode = 4 //The type of a {@link LexerPopModeAction} action. + LexerActionTypePushMode = 5 //The type of a {@link LexerPushModeAction} action. + LexerActionTypeSkip = 6 //The type of a {@link LexerSkipAction} action. + LexerActionTypeType = 7 //The type of a {@link LexerTypeAction} action. +) + +type LexerAction interface { + getActionType() int + getIsPositionDependent() bool + execute(lexer Lexer) + Hash() int + Equals(other LexerAction) bool +} + +type BaseLexerAction struct { + actionType int + isPositionDependent bool +} + +func NewBaseLexerAction(action int) *BaseLexerAction { + la := new(BaseLexerAction) + + la.actionType = action + la.isPositionDependent = false + + return la +} + +func (b *BaseLexerAction) execute(lexer Lexer) { + panic("Not implemented") +} + +func (b *BaseLexerAction) getActionType() int { + return b.actionType +} + +func (b *BaseLexerAction) getIsPositionDependent() bool { + return b.isPositionDependent +} + +func (b *BaseLexerAction) Hash() int { + return b.actionType +} + +func (b *BaseLexerAction) Equals(other LexerAction) bool { + return b == other +} + +// Implements the {@code Skip} lexer action by calling {@link Lexer//Skip}. +// +//The {@code Skip} command does not have any parameters, so l action is +// implemented as a singleton instance exposed by {@link //INSTANCE}.
+type LexerSkipAction struct { + *BaseLexerAction +} + +func NewLexerSkipAction() *LexerSkipAction { + la := new(LexerSkipAction) + la.BaseLexerAction = NewBaseLexerAction(LexerActionTypeSkip) + return la +} + +// Provides a singleton instance of l parameterless lexer action. +var LexerSkipActionINSTANCE = NewLexerSkipAction() + +func (l *LexerSkipAction) execute(lexer Lexer) { + lexer.Skip() +} + +func (l *LexerSkipAction) String() string { + return "skip" +} + +// Implements the {@code type} lexer action by calling {@link Lexer//setType} +// +// with the assigned type. +type LexerTypeAction struct { + *BaseLexerAction + + thetype int +} + +func NewLexerTypeAction(thetype int) *LexerTypeAction { + l := new(LexerTypeAction) + l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeType) + l.thetype = thetype + return l +} + +func (l *LexerTypeAction) execute(lexer Lexer) { + lexer.SetType(l.thetype) +} + +func (l *LexerTypeAction) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, l.actionType) + h = murmurUpdate(h, l.thetype) + return murmurFinish(h, 2) +} + +func (l *LexerTypeAction) Equals(other LexerAction) bool { + if l == other { + return true + } else if _, ok := other.(*LexerTypeAction); !ok { + return false + } else { + return l.thetype == other.(*LexerTypeAction).thetype + } +} + +func (l *LexerTypeAction) String() string { + return "actionType(" + strconv.Itoa(l.thetype) + ")" +} + +// Implements the {@code pushMode} lexer action by calling +// {@link Lexer//pushMode} with the assigned mode. +type LexerPushModeAction struct { + *BaseLexerAction + + mode int +} + +func NewLexerPushModeAction(mode int) *LexerPushModeAction { + + l := new(LexerPushModeAction) + l.BaseLexerAction = NewBaseLexerAction(LexerActionTypePushMode) + + l.mode = mode + return l +} + +//This action is implemented by calling {@link Lexer//pushMode} with the +// value provided by {@link //getMode}.
+func (l *LexerPushModeAction) execute(lexer Lexer) { + lexer.PushMode(l.mode) +} + +func (l *LexerPushModeAction) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, l.actionType) + h = murmurUpdate(h, l.mode) + return murmurFinish(h, 2) +} + +func (l *LexerPushModeAction) Equals(other LexerAction) bool { + if l == other { + return true + } else if _, ok := other.(*LexerPushModeAction); !ok { + return false + } else { + return l.mode == other.(*LexerPushModeAction).mode + } +} + +func (l *LexerPushModeAction) String() string { + return "pushMode(" + strconv.Itoa(l.mode) + ")" +} + +// Implements the {@code popMode} lexer action by calling {@link Lexer//popMode}. +// +//The {@code popMode} command does not have any parameters, so l action is +// implemented as a singleton instance exposed by {@link //INSTANCE}.
+type LexerPopModeAction struct { + *BaseLexerAction +} + +func NewLexerPopModeAction() *LexerPopModeAction { + + l := new(LexerPopModeAction) + + l.BaseLexerAction = NewBaseLexerAction(LexerActionTypePopMode) + + return l +} + +var LexerPopModeActionINSTANCE = NewLexerPopModeAction() + +//This action is implemented by calling {@link Lexer//popMode}.
+func (l *LexerPopModeAction) execute(lexer Lexer) { + lexer.PopMode() +} + +func (l *LexerPopModeAction) String() string { + return "popMode" +} + +// Implements the {@code more} lexer action by calling {@link Lexer//more}. +// +//The {@code more} command does not have any parameters, so l action is +// implemented as a singleton instance exposed by {@link //INSTANCE}.
+ +type LexerMoreAction struct { + *BaseLexerAction +} + +func NewLexerMoreAction() *LexerMoreAction { + l := new(LexerMoreAction) + l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeMore) + + return l +} + +var LexerMoreActionINSTANCE = NewLexerMoreAction() + +//This action is implemented by calling {@link Lexer//popMode}.
+func (l *LexerMoreAction) execute(lexer Lexer) { + lexer.More() +} + +func (l *LexerMoreAction) String() string { + return "more" +} + +// Implements the {@code mode} lexer action by calling {@link Lexer//mode} with +// the assigned mode. +type LexerModeAction struct { + *BaseLexerAction + + mode int +} + +func NewLexerModeAction(mode int) *LexerModeAction { + l := new(LexerModeAction) + l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeMode) + l.mode = mode + return l +} + +//This action is implemented by calling {@link Lexer//mode} with the +// value provided by {@link //getMode}.
+func (l *LexerModeAction) execute(lexer Lexer) { + lexer.SetMode(l.mode) +} + +func (l *LexerModeAction) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, l.actionType) + h = murmurUpdate(h, l.mode) + return murmurFinish(h, 2) +} + +func (l *LexerModeAction) Equals(other LexerAction) bool { + if l == other { + return true + } else if _, ok := other.(*LexerModeAction); !ok { + return false + } else { + return l.mode == other.(*LexerModeAction).mode + } +} + +func (l *LexerModeAction) String() string { + return "mode(" + strconv.Itoa(l.mode) + ")" +} + +// Executes a custom lexer action by calling {@link Recognizer//action} with the +// rule and action indexes assigned to the custom action. The implementation of +// a custom action is added to the generated code for the lexer in an override +// of {@link Recognizer//action} when the grammar is compiled. +// +//This class may represent embedded actions created with the {...}
+// syntax in ANTLR 4, as well as actions created for lexer commands where the
+// command argument could not be evaluated when the grammar was compiled.
Custom actions are implemented by calling {@link Lexer//action} with the +// appropriate rule and action indexes.
+func (l *LexerCustomAction) execute(lexer Lexer) { + lexer.Action(nil, l.ruleIndex, l.actionIndex) +} + +func (l *LexerCustomAction) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, l.actionType) + h = murmurUpdate(h, l.ruleIndex) + h = murmurUpdate(h, l.actionIndex) + return murmurFinish(h, 3) +} + +func (l *LexerCustomAction) Equals(other LexerAction) bool { + if l == other { + return true + } else if _, ok := other.(*LexerCustomAction); !ok { + return false + } else { + return l.ruleIndex == other.(*LexerCustomAction).ruleIndex && + l.actionIndex == other.(*LexerCustomAction).actionIndex + } +} + +// Implements the {@code channel} lexer action by calling +// {@link Lexer//setChannel} with the assigned channel. +// Constructs a New{@code channel} action with the specified channel value. +// @param channel The channel value to pass to {@link Lexer//setChannel}. +type LexerChannelAction struct { + *BaseLexerAction + + channel int +} + +func NewLexerChannelAction(channel int) *LexerChannelAction { + l := new(LexerChannelAction) + l.BaseLexerAction = NewBaseLexerAction(LexerActionTypeChannel) + l.channel = channel + return l +} + +//This action is implemented by calling {@link Lexer//setChannel} with the +// value provided by {@link //getChannel}.
+func (l *LexerChannelAction) execute(lexer Lexer) { + lexer.SetChannel(l.channel) +} + +func (l *LexerChannelAction) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, l.actionType) + h = murmurUpdate(h, l.channel) + return murmurFinish(h, 2) +} + +func (l *LexerChannelAction) Equals(other LexerAction) bool { + if l == other { + return true + } else if _, ok := other.(*LexerChannelAction); !ok { + return false + } else { + return l.channel == other.(*LexerChannelAction).channel + } +} + +func (l *LexerChannelAction) String() string { + return "channel(" + strconv.Itoa(l.channel) + ")" +} + +// This implementation of {@link LexerAction} is used for tracking input offsets +// for position-dependent actions within a {@link LexerActionExecutor}. +// +//This action is not serialized as part of the ATN, and is only required for +// position-dependent lexer actions which appear at a location other than the +// end of a rule. For more information about DFA optimizations employed for +// lexer actions, see {@link LexerActionExecutor//append} and +// {@link LexerActionExecutor//fixOffsetBeforeMatch}.
+ +// Constructs a Newindexed custom action by associating a character offset +// with a {@link LexerAction}. +// +//Note: This class is only required for lexer actions for which +// {@link LexerAction//isPositionDependent} returns {@code true}.
+// +// @param offset The offset into the input {@link CharStream}, relative to +// the token start index, at which the specified lexer action should be +// executed. +// @param action The lexer action to execute at a particular offset in the +// input {@link CharStream}. +type LexerIndexedCustomAction struct { + *BaseLexerAction + + offset int + lexerAction LexerAction + isPositionDependent bool +} + +func NewLexerIndexedCustomAction(offset int, lexerAction LexerAction) *LexerIndexedCustomAction { + + l := new(LexerIndexedCustomAction) + l.BaseLexerAction = NewBaseLexerAction(lexerAction.getActionType()) + + l.offset = offset + l.lexerAction = lexerAction + l.isPositionDependent = true + + return l +} + +//This method calls {@link //execute} on the result of {@link //getAction} +// using the provided {@code lexer}.
+func (l *LexerIndexedCustomAction) execute(lexer Lexer) { + // assume the input stream position was properly set by the calling code + l.lexerAction.execute(lexer) +} + +func (l *LexerIndexedCustomAction) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, l.offset) + h = murmurUpdate(h, l.lexerAction.Hash()) + return murmurFinish(h, 2) +} + +func (l *LexerIndexedCustomAction) equals(other LexerAction) bool { + if l == other { + return true + } else if _, ok := other.(*LexerIndexedCustomAction); !ok { + return false + } else { + return l.offset == other.(*LexerIndexedCustomAction).offset && + l.lexerAction.Equals(other.(*LexerIndexedCustomAction).lexerAction) + } +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_action_executor.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_action_executor.go index be1ba7a7e3..8666cda376 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_action_executor.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_action_executor.go @@ -1,186 +1,186 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import "golang.org/x/exp/slices" - -// Represents an executor for a sequence of lexer actions which traversed during -// the Matching operation of a lexer rule (token). -// -//The executor tracks position information for position-dependent lexer actions -// efficiently, ensuring that actions appearing only at the end of the rule do -// not cause bloating of the {@link DFA} created for the lexer.
- -type LexerActionExecutor struct { - lexerActions []LexerAction - cachedHash int -} - -func NewLexerActionExecutor(lexerActions []LexerAction) *LexerActionExecutor { - - if lexerActions == nil { - lexerActions = make([]LexerAction, 0) - } - - l := new(LexerActionExecutor) - - l.lexerActions = lexerActions - - // Caches the result of {@link //hashCode} since the hash code is an element - // of the performance-critical {@link LexerATNConfig//hashCode} operation. - l.cachedHash = murmurInit(57) - for _, a := range lexerActions { - l.cachedHash = murmurUpdate(l.cachedHash, a.Hash()) - } - - return l -} - -// Creates a {@link LexerActionExecutor} which executes the actions for -// the input {@code lexerActionExecutor} followed by a specified -// {@code lexerAction}. -// -// @param lexerActionExecutor The executor for actions already traversed by -// the lexer while Matching a token within a particular -// {@link LexerATNConfig}. If this is {@code nil}, the method behaves as -// though it were an empty executor. -// @param lexerAction The lexer action to execute after the actions -// specified in {@code lexerActionExecutor}. -// -// @return A {@link LexerActionExecutor} for executing the combine actions -// of {@code lexerActionExecutor} and {@code lexerAction}. -func LexerActionExecutorappend(lexerActionExecutor *LexerActionExecutor, lexerAction LexerAction) *LexerActionExecutor { - if lexerActionExecutor == nil { - return NewLexerActionExecutor([]LexerAction{lexerAction}) - } - - return NewLexerActionExecutor(append(lexerActionExecutor.lexerActions, lexerAction)) -} - -// Creates a {@link LexerActionExecutor} which encodes the current offset -// for position-dependent lexer actions. -// -//Normally, when the executor encounters lexer actions where -// {@link LexerAction//isPositionDependent} returns {@code true}, it calls -// {@link IntStream//seek} on the input {@link CharStream} to set the input -// position to the end of the current token. This behavior provides -// for efficient DFA representation of lexer actions which appear at the end -// of a lexer rule, even when the lexer rule Matches a variable number of -// characters.
-// -//Prior to traversing a Match transition in the ATN, the current offset -// from the token start index is assigned to all position-dependent lexer -// actions which have not already been assigned a fixed offset. By storing -// the offsets relative to the token start index, the DFA representation of -// lexer actions which appear in the middle of tokens remains efficient due -// to sharing among tokens of the same length, regardless of their absolute -// position in the input stream.
-// -//If the current executor already has offsets assigned to all -// position-dependent lexer actions, the method returns {@code this}.
-// -// @param offset The current offset to assign to all position-dependent -// lexer actions which do not already have offsets assigned. -// -// @return A {@link LexerActionExecutor} which stores input stream offsets -// for all position-dependent lexer actions. -// / -func (l *LexerActionExecutor) fixOffsetBeforeMatch(offset int) *LexerActionExecutor { - var updatedLexerActions []LexerAction - for i := 0; i < len(l.lexerActions); i++ { - _, ok := l.lexerActions[i].(*LexerIndexedCustomAction) - if l.lexerActions[i].getIsPositionDependent() && !ok { - if updatedLexerActions == nil { - updatedLexerActions = make([]LexerAction, 0) - - for _, a := range l.lexerActions { - updatedLexerActions = append(updatedLexerActions, a) - } - } - - updatedLexerActions[i] = NewLexerIndexedCustomAction(offset, l.lexerActions[i]) - } - } - if updatedLexerActions == nil { - return l - } - - return NewLexerActionExecutor(updatedLexerActions) -} - -// Execute the actions encapsulated by l executor within the context of a -// particular {@link Lexer}. -// -//This method calls {@link IntStream//seek} to set the position of the -// {@code input} {@link CharStream} prior to calling -// {@link LexerAction//execute} on a position-dependent action. Before the -// method returns, the input position will be restored to the same position -// it was in when the method was invoked.
-// -// @param lexer The lexer instance. -// @param input The input stream which is the source for the current token. -// When l method is called, the current {@link IntStream//index} for -// {@code input} should be the start of the following token, i.e. 1 -// character past the end of the current token. -// @param startIndex The token start index. This value may be passed to -// {@link IntStream//seek} to set the {@code input} position to the beginning -// of the token. -// / -func (l *LexerActionExecutor) execute(lexer Lexer, input CharStream, startIndex int) { - requiresSeek := false - stopIndex := input.Index() - - defer func() { - if requiresSeek { - input.Seek(stopIndex) - } - }() - - for i := 0; i < len(l.lexerActions); i++ { - lexerAction := l.lexerActions[i] - if la, ok := lexerAction.(*LexerIndexedCustomAction); ok { - offset := la.offset - input.Seek(startIndex + offset) - lexerAction = la.lexerAction - requiresSeek = (startIndex + offset) != stopIndex - } else if lexerAction.getIsPositionDependent() { - input.Seek(stopIndex) - requiresSeek = false - } - lexerAction.execute(lexer) - } -} - -func (l *LexerActionExecutor) Hash() int { - if l == nil { - // TODO: Why is this here? l should not be nil - return 61 - } - - // TODO: This is created from the action itself when the struct is created - will this be an issue at some point? Java uses the runtime assign hashcode - return l.cachedHash -} - -func (l *LexerActionExecutor) Equals(other interface{}) bool { - if l == other { - return true - } - othert, ok := other.(*LexerActionExecutor) - if !ok { - return false - } - if othert == nil { - return false - } - if l.cachedHash != othert.cachedHash { - return false - } - if len(l.lexerActions) != len(othert.lexerActions) { - return false - } - return slices.EqualFunc(l.lexerActions, othert.lexerActions, func(i, j LexerAction) bool { - return i.Equals(j) - }) -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import "golang.org/x/exp/slices" + +// Represents an executor for a sequence of lexer actions which traversed during +// the Matching operation of a lexer rule (token). +// +//The executor tracks position information for position-dependent lexer actions +// efficiently, ensuring that actions appearing only at the end of the rule do +// not cause bloating of the {@link DFA} created for the lexer.
+ +type LexerActionExecutor struct { + lexerActions []LexerAction + cachedHash int +} + +func NewLexerActionExecutor(lexerActions []LexerAction) *LexerActionExecutor { + + if lexerActions == nil { + lexerActions = make([]LexerAction, 0) + } + + l := new(LexerActionExecutor) + + l.lexerActions = lexerActions + + // Caches the result of {@link //hashCode} since the hash code is an element + // of the performance-critical {@link LexerATNConfig//hashCode} operation. + l.cachedHash = murmurInit(57) + for _, a := range lexerActions { + l.cachedHash = murmurUpdate(l.cachedHash, a.Hash()) + } + + return l +} + +// Creates a {@link LexerActionExecutor} which executes the actions for +// the input {@code lexerActionExecutor} followed by a specified +// {@code lexerAction}. +// +// @param lexerActionExecutor The executor for actions already traversed by +// the lexer while Matching a token within a particular +// {@link LexerATNConfig}. If this is {@code nil}, the method behaves as +// though it were an empty executor. +// @param lexerAction The lexer action to execute after the actions +// specified in {@code lexerActionExecutor}. +// +// @return A {@link LexerActionExecutor} for executing the combine actions +// of {@code lexerActionExecutor} and {@code lexerAction}. +func LexerActionExecutorappend(lexerActionExecutor *LexerActionExecutor, lexerAction LexerAction) *LexerActionExecutor { + if lexerActionExecutor == nil { + return NewLexerActionExecutor([]LexerAction{lexerAction}) + } + + return NewLexerActionExecutor(append(lexerActionExecutor.lexerActions, lexerAction)) +} + +// Creates a {@link LexerActionExecutor} which encodes the current offset +// for position-dependent lexer actions. +// +//Normally, when the executor encounters lexer actions where +// {@link LexerAction//isPositionDependent} returns {@code true}, it calls +// {@link IntStream//seek} on the input {@link CharStream} to set the input +// position to the end of the current token. This behavior provides +// for efficient DFA representation of lexer actions which appear at the end +// of a lexer rule, even when the lexer rule Matches a variable number of +// characters.
+// +//Prior to traversing a Match transition in the ATN, the current offset +// from the token start index is assigned to all position-dependent lexer +// actions which have not already been assigned a fixed offset. By storing +// the offsets relative to the token start index, the DFA representation of +// lexer actions which appear in the middle of tokens remains efficient due +// to sharing among tokens of the same length, regardless of their absolute +// position in the input stream.
+// +//If the current executor already has offsets assigned to all +// position-dependent lexer actions, the method returns {@code this}.
+// +// @param offset The current offset to assign to all position-dependent +// lexer actions which do not already have offsets assigned. +// +// @return A {@link LexerActionExecutor} which stores input stream offsets +// for all position-dependent lexer actions. +// / +func (l *LexerActionExecutor) fixOffsetBeforeMatch(offset int) *LexerActionExecutor { + var updatedLexerActions []LexerAction + for i := 0; i < len(l.lexerActions); i++ { + _, ok := l.lexerActions[i].(*LexerIndexedCustomAction) + if l.lexerActions[i].getIsPositionDependent() && !ok { + if updatedLexerActions == nil { + updatedLexerActions = make([]LexerAction, 0) + + for _, a := range l.lexerActions { + updatedLexerActions = append(updatedLexerActions, a) + } + } + + updatedLexerActions[i] = NewLexerIndexedCustomAction(offset, l.lexerActions[i]) + } + } + if updatedLexerActions == nil { + return l + } + + return NewLexerActionExecutor(updatedLexerActions) +} + +// Execute the actions encapsulated by l executor within the context of a +// particular {@link Lexer}. +// +//This method calls {@link IntStream//seek} to set the position of the +// {@code input} {@link CharStream} prior to calling +// {@link LexerAction//execute} on a position-dependent action. Before the +// method returns, the input position will be restored to the same position +// it was in when the method was invoked.
+// +// @param lexer The lexer instance. +// @param input The input stream which is the source for the current token. +// When l method is called, the current {@link IntStream//index} for +// {@code input} should be the start of the following token, i.e. 1 +// character past the end of the current token. +// @param startIndex The token start index. This value may be passed to +// {@link IntStream//seek} to set the {@code input} position to the beginning +// of the token. +// / +func (l *LexerActionExecutor) execute(lexer Lexer, input CharStream, startIndex int) { + requiresSeek := false + stopIndex := input.Index() + + defer func() { + if requiresSeek { + input.Seek(stopIndex) + } + }() + + for i := 0; i < len(l.lexerActions); i++ { + lexerAction := l.lexerActions[i] + if la, ok := lexerAction.(*LexerIndexedCustomAction); ok { + offset := la.offset + input.Seek(startIndex + offset) + lexerAction = la.lexerAction + requiresSeek = (startIndex + offset) != stopIndex + } else if lexerAction.getIsPositionDependent() { + input.Seek(stopIndex) + requiresSeek = false + } + lexerAction.execute(lexer) + } +} + +func (l *LexerActionExecutor) Hash() int { + if l == nil { + // TODO: Why is this here? l should not be nil + return 61 + } + + // TODO: This is created from the action itself when the struct is created - will this be an issue at some point? Java uses the runtime assign hashcode + return l.cachedHash +} + +func (l *LexerActionExecutor) Equals(other interface{}) bool { + if l == other { + return true + } + othert, ok := other.(*LexerActionExecutor) + if !ok { + return false + } + if othert == nil { + return false + } + if l.cachedHash != othert.cachedHash { + return false + } + if len(l.lexerActions) != len(othert.lexerActions) { + return false + } + return slices.EqualFunc(l.lexerActions, othert.lexerActions, func(i, j LexerAction) bool { + return i.Equals(j) + }) +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_atn_simulator.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_atn_simulator.go index c573b75210..e0299f9edf 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_atn_simulator.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/lexer_atn_simulator.go @@ -1,684 +1,684 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "fmt" - "strconv" - "strings" -) - -var ( - LexerATNSimulatorDebug = false - LexerATNSimulatorDFADebug = false - - LexerATNSimulatorMinDFAEdge = 0 - LexerATNSimulatorMaxDFAEdge = 127 // forces unicode to stay in ATN - - LexerATNSimulatorMatchCalls = 0 -) - -type ILexerATNSimulator interface { - IATNSimulator - - reset() - Match(input CharStream, mode int) int - GetCharPositionInLine() int - GetLine() int - GetText(input CharStream) string - Consume(input CharStream) -} - -type LexerATNSimulator struct { - *BaseATNSimulator - - recog Lexer - predictionMode int - mergeCache DoubleDict - startIndex int - Line int - CharPositionInLine int - mode int - prevAccept *SimState - MatchCalls int -} - -func NewLexerATNSimulator(recog Lexer, atn *ATN, decisionToDFA []*DFA, sharedContextCache *PredictionContextCache) *LexerATNSimulator { - l := new(LexerATNSimulator) - - l.BaseATNSimulator = NewBaseATNSimulator(atn, sharedContextCache) - - l.decisionToDFA = decisionToDFA - l.recog = recog - // The current token's starting index into the character stream. - // Shared across DFA to ATN simulation in case the ATN fails and the - // DFA did not have a previous accept state. In l case, we use the - // ATN-generated exception object. - l.startIndex = -1 - // line number 1..n within the input/// - l.Line = 1 - // The index of the character relative to the beginning of the line - // 0..n-1/// - l.CharPositionInLine = 0 - l.mode = LexerDefaultMode - // Used during DFA/ATN exec to record the most recent accept configuration - // info - l.prevAccept = NewSimState() - // done - return l -} - -func (l *LexerATNSimulator) copyState(simulator *LexerATNSimulator) { - l.CharPositionInLine = simulator.CharPositionInLine - l.Line = simulator.Line - l.mode = simulator.mode - l.startIndex = simulator.startIndex -} - -func (l *LexerATNSimulator) Match(input CharStream, mode int) int { - l.MatchCalls++ - l.mode = mode - mark := input.Mark() - - defer func() { - input.Release(mark) - }() - - l.startIndex = input.Index() - l.prevAccept.reset() - - dfa := l.decisionToDFA[mode] - - var s0 *DFAState - l.atn.stateMu.RLock() - s0 = dfa.getS0() - l.atn.stateMu.RUnlock() - - if s0 == nil { - return l.MatchATN(input) - } - - return l.execATN(input, s0) -} - -func (l *LexerATNSimulator) reset() { - l.prevAccept.reset() - l.startIndex = -1 - l.Line = 1 - l.CharPositionInLine = 0 - l.mode = LexerDefaultMode -} - -func (l *LexerATNSimulator) MatchATN(input CharStream) int { - startState := l.atn.modeToStartState[l.mode] - - if LexerATNSimulatorDebug { - fmt.Println("MatchATN mode " + strconv.Itoa(l.mode) + " start: " + startState.String()) - } - oldMode := l.mode - s0Closure := l.computeStartState(input, startState) - suppressEdge := s0Closure.hasSemanticContext - s0Closure.hasSemanticContext = false - - next := l.addDFAState(s0Closure, suppressEdge) - - predict := l.execATN(input, next) - - if LexerATNSimulatorDebug { - fmt.Println("DFA after MatchATN: " + l.decisionToDFA[oldMode].ToLexerString()) - } - return predict -} - -func (l *LexerATNSimulator) execATN(input CharStream, ds0 *DFAState) int { - - if LexerATNSimulatorDebug { - fmt.Println("start state closure=" + ds0.configs.String()) - } - if ds0.isAcceptState { - // allow zero-length tokens - l.captureSimState(l.prevAccept, input, ds0) - } - t := input.LA(1) - s := ds0 // s is current/from DFA state - - for { // while more work - if LexerATNSimulatorDebug { - fmt.Println("execATN loop starting closure: " + s.configs.String()) - } - - // As we move src->trg, src->trg, we keep track of the previous trg to - // avoid looking up the DFA state again, which is expensive. - // If the previous target was already part of the DFA, we might - // be able to avoid doing a reach operation upon t. If s!=nil, - // it means that semantic predicates didn't prevent us from - // creating a DFA state. Once we know s!=nil, we check to see if - // the DFA state has an edge already for t. If so, we can just reuse - // it's configuration set there's no point in re-computing it. - // This is kind of like doing DFA simulation within the ATN - // simulation because DFA simulation is really just a way to avoid - // computing reach/closure sets. Technically, once we know that - // we have a previously added DFA state, we could jump over to - // the DFA simulator. But, that would mean popping back and forth - // a lot and making things more complicated algorithmically. - // This optimization makes a lot of sense for loops within DFA. - // A character will take us back to an existing DFA state - // that already has lots of edges out of it. e.g., .* in comments. - target := l.getExistingTargetState(s, t) - if target == nil { - target = l.computeTargetState(input, s, t) - // print("Computed:" + str(target)) - } - if target == ATNSimulatorError { - break - } - // If l is a consumable input element, make sure to consume before - // capturing the accept state so the input index, line, and char - // position accurately reflect the state of the interpreter at the - // end of the token. - if t != TokenEOF { - l.Consume(input) - } - if target.isAcceptState { - l.captureSimState(l.prevAccept, input, target) - if t == TokenEOF { - break - } - } - t = input.LA(1) - s = target // flip current DFA target becomes Newsrc/from state - } - - return l.failOrAccept(l.prevAccept, input, s.configs, t) -} - -// Get an existing target state for an edge in the DFA. If the target state -// for the edge has not yet been computed or is otherwise not available, -// l method returns {@code nil}. -// -// @param s The current DFA state -// @param t The next input symbol -// @return The existing target DFA state for the given input symbol -// {@code t}, or {@code nil} if the target state for l edge is not -// already cached -func (l *LexerATNSimulator) getExistingTargetState(s *DFAState, t int) *DFAState { - if t < LexerATNSimulatorMinDFAEdge || t > LexerATNSimulatorMaxDFAEdge { - return nil - } - - l.atn.edgeMu.RLock() - defer l.atn.edgeMu.RUnlock() - if s.getEdges() == nil { - return nil - } - target := s.getIthEdge(t - LexerATNSimulatorMinDFAEdge) - if LexerATNSimulatorDebug && target != nil { - fmt.Println("reuse state " + strconv.Itoa(s.stateNumber) + " edge to " + strconv.Itoa(target.stateNumber)) - } - return target -} - -// Compute a target state for an edge in the DFA, and attempt to add the -// computed state and corresponding edge to the DFA. -// -// @param input The input stream -// @param s The current DFA state -// @param t The next input symbol -// -// @return The computed target DFA state for the given input symbol -// {@code t}. If {@code t} does not lead to a valid DFA state, l method -// returns {@link //ERROR}. -func (l *LexerATNSimulator) computeTargetState(input CharStream, s *DFAState, t int) *DFAState { - reach := NewOrderedATNConfigSet() - - // if we don't find an existing DFA state - // Fill reach starting from closure, following t transitions - l.getReachableConfigSet(input, s.configs, reach.BaseATNConfigSet, t) - - if len(reach.configs) == 0 { // we got nowhere on t from s - if !reach.hasSemanticContext { - // we got nowhere on t, don't panic out l knowledge it'd - // cause a failover from DFA later. - l.addDFAEdge(s, t, ATNSimulatorError, nil) - } - // stop when we can't Match any more char - return ATNSimulatorError - } - // Add an edge from s to target DFA found/created for reach - return l.addDFAEdge(s, t, nil, reach.BaseATNConfigSet) -} - -func (l *LexerATNSimulator) failOrAccept(prevAccept *SimState, input CharStream, reach ATNConfigSet, t int) int { - if l.prevAccept.dfaState != nil { - lexerActionExecutor := prevAccept.dfaState.lexerActionExecutor - l.accept(input, lexerActionExecutor, l.startIndex, prevAccept.index, prevAccept.line, prevAccept.column) - return prevAccept.dfaState.prediction - } - - // if no accept and EOF is first char, return EOF - if t == TokenEOF && input.Index() == l.startIndex { - return TokenEOF - } - - panic(NewLexerNoViableAltException(l.recog, input, l.startIndex, reach)) -} - -// Given a starting configuration set, figure out all ATN configurations -// we can reach upon input {@code t}. Parameter {@code reach} is a return -// parameter. -func (l *LexerATNSimulator) getReachableConfigSet(input CharStream, closure ATNConfigSet, reach ATNConfigSet, t int) { - // l is used to Skip processing for configs which have a lower priority - // than a config that already reached an accept state for the same rule - SkipAlt := ATNInvalidAltNumber - - for _, cfg := range closure.GetItems() { - currentAltReachedAcceptState := (cfg.GetAlt() == SkipAlt) - if currentAltReachedAcceptState && cfg.(*LexerATNConfig).passedThroughNonGreedyDecision { - continue - } - - if LexerATNSimulatorDebug { - - fmt.Printf("testing %s at %s\n", l.GetTokenName(t), cfg.String()) // l.recog, true)) - } - - for _, trans := range cfg.GetState().GetTransitions() { - target := l.getReachableTarget(trans, t) - if target != nil { - lexerActionExecutor := cfg.(*LexerATNConfig).lexerActionExecutor - if lexerActionExecutor != nil { - lexerActionExecutor = lexerActionExecutor.fixOffsetBeforeMatch(input.Index() - l.startIndex) - } - treatEOFAsEpsilon := (t == TokenEOF) - config := NewLexerATNConfig3(cfg.(*LexerATNConfig), target, lexerActionExecutor) - if l.closure(input, config, reach, - currentAltReachedAcceptState, true, treatEOFAsEpsilon) { - // any remaining configs for l alt have a lower priority - // than the one that just reached an accept state. - SkipAlt = cfg.GetAlt() - } - } - } - } -} - -func (l *LexerATNSimulator) accept(input CharStream, lexerActionExecutor *LexerActionExecutor, startIndex, index, line, charPos int) { - if LexerATNSimulatorDebug { - fmt.Printf("ACTION %v\n", lexerActionExecutor) - } - // seek to after last char in token - input.Seek(index) - l.Line = line - l.CharPositionInLine = charPos - if lexerActionExecutor != nil && l.recog != nil { - lexerActionExecutor.execute(l.recog, input, startIndex) - } -} - -func (l *LexerATNSimulator) getReachableTarget(trans Transition, t int) ATNState { - if trans.Matches(t, 0, LexerMaxCharValue) { - return trans.getTarget() - } - - return nil -} - -func (l *LexerATNSimulator) computeStartState(input CharStream, p ATNState) *OrderedATNConfigSet { - configs := NewOrderedATNConfigSet() - for i := 0; i < len(p.GetTransitions()); i++ { - target := p.GetTransitions()[i].getTarget() - cfg := NewLexerATNConfig6(target, i+1, BasePredictionContextEMPTY) - l.closure(input, cfg, configs, false, false, false) - } - - return configs -} - -// Since the alternatives within any lexer decision are ordered by -// preference, l method stops pursuing the closure as soon as an accept -// state is reached. After the first accept state is reached by depth-first -// search from {@code config}, all other (potentially reachable) states for -// l rule would have a lower priority. -// -// @return {@code true} if an accept state is reached, otherwise -// {@code false}. -func (l *LexerATNSimulator) closure(input CharStream, config *LexerATNConfig, configs ATNConfigSet, - currentAltReachedAcceptState, speculative, treatEOFAsEpsilon bool) bool { - - if LexerATNSimulatorDebug { - fmt.Println("closure(" + config.String() + ")") // config.String(l.recog, true) + ")") - } - - _, ok := config.state.(*RuleStopState) - if ok { - - if LexerATNSimulatorDebug { - if l.recog != nil { - fmt.Printf("closure at %s rule stop %s\n", l.recog.GetRuleNames()[config.state.GetRuleIndex()], config) - } else { - fmt.Printf("closure at rule stop %s\n", config) - } - } - - if config.context == nil || config.context.hasEmptyPath() { - if config.context == nil || config.context.isEmpty() { - configs.Add(config, nil) - return true - } - - configs.Add(NewLexerATNConfig2(config, config.state, BasePredictionContextEMPTY), nil) - currentAltReachedAcceptState = true - } - if config.context != nil && !config.context.isEmpty() { - for i := 0; i < config.context.length(); i++ { - if config.context.getReturnState(i) != BasePredictionContextEmptyReturnState { - newContext := config.context.GetParent(i) // "pop" return state - returnState := l.atn.states[config.context.getReturnState(i)] - cfg := NewLexerATNConfig2(config, returnState, newContext) - currentAltReachedAcceptState = l.closure(input, cfg, configs, currentAltReachedAcceptState, speculative, treatEOFAsEpsilon) - } - } - } - return currentAltReachedAcceptState - } - // optimization - if !config.state.GetEpsilonOnlyTransitions() { - if !currentAltReachedAcceptState || !config.passedThroughNonGreedyDecision { - configs.Add(config, nil) - } - } - for j := 0; j < len(config.state.GetTransitions()); j++ { - trans := config.state.GetTransitions()[j] - cfg := l.getEpsilonTarget(input, config, trans, configs, speculative, treatEOFAsEpsilon) - if cfg != nil { - currentAltReachedAcceptState = l.closure(input, cfg, configs, - currentAltReachedAcceptState, speculative, treatEOFAsEpsilon) - } - } - return currentAltReachedAcceptState -} - -// side-effect: can alter configs.hasSemanticContext -func (l *LexerATNSimulator) getEpsilonTarget(input CharStream, config *LexerATNConfig, trans Transition, - configs ATNConfigSet, speculative, treatEOFAsEpsilon bool) *LexerATNConfig { - - var cfg *LexerATNConfig - - if trans.getSerializationType() == TransitionRULE { - - rt := trans.(*RuleTransition) - newContext := SingletonBasePredictionContextCreate(config.context, rt.followState.GetStateNumber()) - cfg = NewLexerATNConfig2(config, trans.getTarget(), newContext) - - } else if trans.getSerializationType() == TransitionPRECEDENCE { - panic("Precedence predicates are not supported in lexers.") - } else if trans.getSerializationType() == TransitionPREDICATE { - // Track traversing semantic predicates. If we traverse, - // we cannot add a DFA state for l "reach" computation - // because the DFA would not test the predicate again in the - // future. Rather than creating collections of semantic predicates - // like v3 and testing them on prediction, v4 will test them on the - // fly all the time using the ATN not the DFA. This is slower but - // semantically it's not used that often. One of the key elements to - // l predicate mechanism is not adding DFA states that see - // predicates immediately afterwards in the ATN. For example, - - // a : ID {p1}? | ID {p2}? - - // should create the start state for rule 'a' (to save start state - // competition), but should not create target of ID state. The - // collection of ATN states the following ID references includes - // states reached by traversing predicates. Since l is when we - // test them, we cannot cash the DFA state target of ID. - - pt := trans.(*PredicateTransition) - - if LexerATNSimulatorDebug { - fmt.Println("EVAL rule " + strconv.Itoa(trans.(*PredicateTransition).ruleIndex) + ":" + strconv.Itoa(pt.predIndex)) - } - configs.SetHasSemanticContext(true) - if l.evaluatePredicate(input, pt.ruleIndex, pt.predIndex, speculative) { - cfg = NewLexerATNConfig4(config, trans.getTarget()) - } - } else if trans.getSerializationType() == TransitionACTION { - if config.context == nil || config.context.hasEmptyPath() { - // execute actions anywhere in the start rule for a token. - // - // TODO: if the entry rule is invoked recursively, some - // actions may be executed during the recursive call. The - // problem can appear when hasEmptyPath() is true but - // isEmpty() is false. In l case, the config needs to be - // split into two contexts - one with just the empty path - // and another with everything but the empty path. - // Unfortunately, the current algorithm does not allow - // getEpsilonTarget to return two configurations, so - // additional modifications are needed before we can support - // the split operation. - lexerActionExecutor := LexerActionExecutorappend(config.lexerActionExecutor, l.atn.lexerActions[trans.(*ActionTransition).actionIndex]) - cfg = NewLexerATNConfig3(config, trans.getTarget(), lexerActionExecutor) - } else { - // ignore actions in referenced rules - cfg = NewLexerATNConfig4(config, trans.getTarget()) - } - } else if trans.getSerializationType() == TransitionEPSILON { - cfg = NewLexerATNConfig4(config, trans.getTarget()) - } else if trans.getSerializationType() == TransitionATOM || - trans.getSerializationType() == TransitionRANGE || - trans.getSerializationType() == TransitionSET { - if treatEOFAsEpsilon { - if trans.Matches(TokenEOF, 0, LexerMaxCharValue) { - cfg = NewLexerATNConfig4(config, trans.getTarget()) - } - } - } - return cfg -} - -// Evaluate a predicate specified in the lexer. -// -//If {@code speculative} is {@code true}, l method was called before -// {@link //consume} for the Matched character. This method should call -// {@link //consume} before evaluating the predicate to ensure position -// sensitive values, including {@link Lexer//GetText}, {@link Lexer//GetLine}, -// and {@link Lexer//getcolumn}, properly reflect the current -// lexer state. This method should restore {@code input} and the simulator -// to the original state before returning (i.e. undo the actions made by the -// call to {@link //consume}.
-// -// @param input The input stream. -// @param ruleIndex The rule containing the predicate. -// @param predIndex The index of the predicate within the rule. -// @param speculative {@code true} if the current index in {@code input} is -// one character before the predicate's location. -// -// @return {@code true} if the specified predicate evaluates to -// {@code true}. -// / -func (l *LexerATNSimulator) evaluatePredicate(input CharStream, ruleIndex, predIndex int, speculative bool) bool { - // assume true if no recognizer was provided - if l.recog == nil { - return true - } - if !speculative { - return l.recog.Sempred(nil, ruleIndex, predIndex) - } - savedcolumn := l.CharPositionInLine - savedLine := l.Line - index := input.Index() - marker := input.Mark() - - defer func() { - l.CharPositionInLine = savedcolumn - l.Line = savedLine - input.Seek(index) - input.Release(marker) - }() - - l.Consume(input) - return l.recog.Sempred(nil, ruleIndex, predIndex) -} - -func (l *LexerATNSimulator) captureSimState(settings *SimState, input CharStream, dfaState *DFAState) { - settings.index = input.Index() - settings.line = l.Line - settings.column = l.CharPositionInLine - settings.dfaState = dfaState -} - -func (l *LexerATNSimulator) addDFAEdge(from *DFAState, tk int, to *DFAState, cfgs ATNConfigSet) *DFAState { - if to == nil && cfgs != nil { - // leading to l call, ATNConfigSet.hasSemanticContext is used as a - // marker indicating dynamic predicate evaluation makes l edge - // dependent on the specific input sequence, so the static edge in the - // DFA should be omitted. The target DFAState is still created since - // execATN has the ability to reSynchronize with the DFA state cache - // following the predicate evaluation step. - // - // TJP notes: next time through the DFA, we see a pred again and eval. - // If that gets us to a previously created (but dangling) DFA - // state, we can continue in pure DFA mode from there. - // / - suppressEdge := cfgs.HasSemanticContext() - cfgs.SetHasSemanticContext(false) - - to = l.addDFAState(cfgs, true) - - if suppressEdge { - return to - } - } - // add the edge - if tk < LexerATNSimulatorMinDFAEdge || tk > LexerATNSimulatorMaxDFAEdge { - // Only track edges within the DFA bounds - return to - } - if LexerATNSimulatorDebug { - fmt.Println("EDGE " + from.String() + " -> " + to.String() + " upon " + strconv.Itoa(tk)) - } - l.atn.edgeMu.Lock() - defer l.atn.edgeMu.Unlock() - if from.getEdges() == nil { - // make room for tokens 1..n and -1 masquerading as index 0 - from.setEdges(make([]*DFAState, LexerATNSimulatorMaxDFAEdge-LexerATNSimulatorMinDFAEdge+1)) - } - from.setIthEdge(tk-LexerATNSimulatorMinDFAEdge, to) // connect - - return to -} - -// Add a NewDFA state if there isn't one with l set of -// configurations already. This method also detects the first -// configuration containing an ATN rule stop state. Later, when -// traversing the DFA, we will know which rule to accept. -func (l *LexerATNSimulator) addDFAState(configs ATNConfigSet, suppressEdge bool) *DFAState { - - proposed := NewDFAState(-1, configs) - var firstConfigWithRuleStopState ATNConfig - - for _, cfg := range configs.GetItems() { - - _, ok := cfg.GetState().(*RuleStopState) - - if ok { - firstConfigWithRuleStopState = cfg - break - } - } - if firstConfigWithRuleStopState != nil { - proposed.isAcceptState = true - proposed.lexerActionExecutor = firstConfigWithRuleStopState.(*LexerATNConfig).lexerActionExecutor - proposed.setPrediction(l.atn.ruleToTokenType[firstConfigWithRuleStopState.GetState().GetRuleIndex()]) - } - dfa := l.decisionToDFA[l.mode] - - l.atn.stateMu.Lock() - defer l.atn.stateMu.Unlock() - existing, present := dfa.states.Get(proposed) - if present { - - // This state was already present, so just return it. - // - proposed = existing - } else { - - // We need to add the new state - // - proposed.stateNumber = dfa.states.Len() - configs.SetReadOnly(true) - proposed.configs = configs - dfa.states.Put(proposed) - } - if !suppressEdge { - dfa.setS0(proposed) - } - return proposed -} - -func (l *LexerATNSimulator) getDFA(mode int) *DFA { - return l.decisionToDFA[mode] -} - -// Get the text Matched so far for the current token. -func (l *LexerATNSimulator) GetText(input CharStream) string { - // index is first lookahead char, don't include. - return input.GetTextFromInterval(NewInterval(l.startIndex, input.Index()-1)) -} - -func (l *LexerATNSimulator) Consume(input CharStream) { - curChar := input.LA(1) - if curChar == int('\n') { - l.Line++ - l.CharPositionInLine = 0 - } else { - l.CharPositionInLine++ - } - input.Consume() -} - -func (l *LexerATNSimulator) GetCharPositionInLine() int { - return l.CharPositionInLine -} - -func (l *LexerATNSimulator) GetLine() int { - return l.Line -} - -func (l *LexerATNSimulator) GetTokenName(tt int) string { - if tt == -1 { - return "EOF" - } - - var sb strings.Builder - sb.Grow(6) - sb.WriteByte('\'') - sb.WriteRune(rune(tt)) - sb.WriteByte('\'') - - return sb.String() -} - -func resetSimState(sim *SimState) { - sim.index = -1 - sim.line = 0 - sim.column = -1 - sim.dfaState = nil -} - -type SimState struct { - index int - line int - column int - dfaState *DFAState -} - -func NewSimState() *SimState { - s := new(SimState) - resetSimState(s) - return s -} - -func (s *SimState) reset() { - resetSimState(s) -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "fmt" + "strconv" + "strings" +) + +var ( + LexerATNSimulatorDebug = false + LexerATNSimulatorDFADebug = false + + LexerATNSimulatorMinDFAEdge = 0 + LexerATNSimulatorMaxDFAEdge = 127 // forces unicode to stay in ATN + + LexerATNSimulatorMatchCalls = 0 +) + +type ILexerATNSimulator interface { + IATNSimulator + + reset() + Match(input CharStream, mode int) int + GetCharPositionInLine() int + GetLine() int + GetText(input CharStream) string + Consume(input CharStream) +} + +type LexerATNSimulator struct { + *BaseATNSimulator + + recog Lexer + predictionMode int + mergeCache DoubleDict + startIndex int + Line int + CharPositionInLine int + mode int + prevAccept *SimState + MatchCalls int +} + +func NewLexerATNSimulator(recog Lexer, atn *ATN, decisionToDFA []*DFA, sharedContextCache *PredictionContextCache) *LexerATNSimulator { + l := new(LexerATNSimulator) + + l.BaseATNSimulator = NewBaseATNSimulator(atn, sharedContextCache) + + l.decisionToDFA = decisionToDFA + l.recog = recog + // The current token's starting index into the character stream. + // Shared across DFA to ATN simulation in case the ATN fails and the + // DFA did not have a previous accept state. In l case, we use the + // ATN-generated exception object. + l.startIndex = -1 + // line number 1..n within the input/// + l.Line = 1 + // The index of the character relative to the beginning of the line + // 0..n-1/// + l.CharPositionInLine = 0 + l.mode = LexerDefaultMode + // Used during DFA/ATN exec to record the most recent accept configuration + // info + l.prevAccept = NewSimState() + // done + return l +} + +func (l *LexerATNSimulator) copyState(simulator *LexerATNSimulator) { + l.CharPositionInLine = simulator.CharPositionInLine + l.Line = simulator.Line + l.mode = simulator.mode + l.startIndex = simulator.startIndex +} + +func (l *LexerATNSimulator) Match(input CharStream, mode int) int { + l.MatchCalls++ + l.mode = mode + mark := input.Mark() + + defer func() { + input.Release(mark) + }() + + l.startIndex = input.Index() + l.prevAccept.reset() + + dfa := l.decisionToDFA[mode] + + var s0 *DFAState + l.atn.stateMu.RLock() + s0 = dfa.getS0() + l.atn.stateMu.RUnlock() + + if s0 == nil { + return l.MatchATN(input) + } + + return l.execATN(input, s0) +} + +func (l *LexerATNSimulator) reset() { + l.prevAccept.reset() + l.startIndex = -1 + l.Line = 1 + l.CharPositionInLine = 0 + l.mode = LexerDefaultMode +} + +func (l *LexerATNSimulator) MatchATN(input CharStream) int { + startState := l.atn.modeToStartState[l.mode] + + if LexerATNSimulatorDebug { + fmt.Println("MatchATN mode " + strconv.Itoa(l.mode) + " start: " + startState.String()) + } + oldMode := l.mode + s0Closure := l.computeStartState(input, startState) + suppressEdge := s0Closure.hasSemanticContext + s0Closure.hasSemanticContext = false + + next := l.addDFAState(s0Closure, suppressEdge) + + predict := l.execATN(input, next) + + if LexerATNSimulatorDebug { + fmt.Println("DFA after MatchATN: " + l.decisionToDFA[oldMode].ToLexerString()) + } + return predict +} + +func (l *LexerATNSimulator) execATN(input CharStream, ds0 *DFAState) int { + + if LexerATNSimulatorDebug { + fmt.Println("start state closure=" + ds0.configs.String()) + } + if ds0.isAcceptState { + // allow zero-length tokens + l.captureSimState(l.prevAccept, input, ds0) + } + t := input.LA(1) + s := ds0 // s is current/from DFA state + + for { // while more work + if LexerATNSimulatorDebug { + fmt.Println("execATN loop starting closure: " + s.configs.String()) + } + + // As we move src->trg, src->trg, we keep track of the previous trg to + // avoid looking up the DFA state again, which is expensive. + // If the previous target was already part of the DFA, we might + // be able to avoid doing a reach operation upon t. If s!=nil, + // it means that semantic predicates didn't prevent us from + // creating a DFA state. Once we know s!=nil, we check to see if + // the DFA state has an edge already for t. If so, we can just reuse + // it's configuration set there's no point in re-computing it. + // This is kind of like doing DFA simulation within the ATN + // simulation because DFA simulation is really just a way to avoid + // computing reach/closure sets. Technically, once we know that + // we have a previously added DFA state, we could jump over to + // the DFA simulator. But, that would mean popping back and forth + // a lot and making things more complicated algorithmically. + // This optimization makes a lot of sense for loops within DFA. + // A character will take us back to an existing DFA state + // that already has lots of edges out of it. e.g., .* in comments. + target := l.getExistingTargetState(s, t) + if target == nil { + target = l.computeTargetState(input, s, t) + // print("Computed:" + str(target)) + } + if target == ATNSimulatorError { + break + } + // If l is a consumable input element, make sure to consume before + // capturing the accept state so the input index, line, and char + // position accurately reflect the state of the interpreter at the + // end of the token. + if t != TokenEOF { + l.Consume(input) + } + if target.isAcceptState { + l.captureSimState(l.prevAccept, input, target) + if t == TokenEOF { + break + } + } + t = input.LA(1) + s = target // flip current DFA target becomes Newsrc/from state + } + + return l.failOrAccept(l.prevAccept, input, s.configs, t) +} + +// Get an existing target state for an edge in the DFA. If the target state +// for the edge has not yet been computed or is otherwise not available, +// l method returns {@code nil}. +// +// @param s The current DFA state +// @param t The next input symbol +// @return The existing target DFA state for the given input symbol +// {@code t}, or {@code nil} if the target state for l edge is not +// already cached +func (l *LexerATNSimulator) getExistingTargetState(s *DFAState, t int) *DFAState { + if t < LexerATNSimulatorMinDFAEdge || t > LexerATNSimulatorMaxDFAEdge { + return nil + } + + l.atn.edgeMu.RLock() + defer l.atn.edgeMu.RUnlock() + if s.getEdges() == nil { + return nil + } + target := s.getIthEdge(t - LexerATNSimulatorMinDFAEdge) + if LexerATNSimulatorDebug && target != nil { + fmt.Println("reuse state " + strconv.Itoa(s.stateNumber) + " edge to " + strconv.Itoa(target.stateNumber)) + } + return target +} + +// Compute a target state for an edge in the DFA, and attempt to add the +// computed state and corresponding edge to the DFA. +// +// @param input The input stream +// @param s The current DFA state +// @param t The next input symbol +// +// @return The computed target DFA state for the given input symbol +// {@code t}. If {@code t} does not lead to a valid DFA state, l method +// returns {@link //ERROR}. +func (l *LexerATNSimulator) computeTargetState(input CharStream, s *DFAState, t int) *DFAState { + reach := NewOrderedATNConfigSet() + + // if we don't find an existing DFA state + // Fill reach starting from closure, following t transitions + l.getReachableConfigSet(input, s.configs, reach.BaseATNConfigSet, t) + + if len(reach.configs) == 0 { // we got nowhere on t from s + if !reach.hasSemanticContext { + // we got nowhere on t, don't panic out l knowledge it'd + // cause a failover from DFA later. + l.addDFAEdge(s, t, ATNSimulatorError, nil) + } + // stop when we can't Match any more char + return ATNSimulatorError + } + // Add an edge from s to target DFA found/created for reach + return l.addDFAEdge(s, t, nil, reach.BaseATNConfigSet) +} + +func (l *LexerATNSimulator) failOrAccept(prevAccept *SimState, input CharStream, reach ATNConfigSet, t int) int { + if l.prevAccept.dfaState != nil { + lexerActionExecutor := prevAccept.dfaState.lexerActionExecutor + l.accept(input, lexerActionExecutor, l.startIndex, prevAccept.index, prevAccept.line, prevAccept.column) + return prevAccept.dfaState.prediction + } + + // if no accept and EOF is first char, return EOF + if t == TokenEOF && input.Index() == l.startIndex { + return TokenEOF + } + + panic(NewLexerNoViableAltException(l.recog, input, l.startIndex, reach)) +} + +// Given a starting configuration set, figure out all ATN configurations +// we can reach upon input {@code t}. Parameter {@code reach} is a return +// parameter. +func (l *LexerATNSimulator) getReachableConfigSet(input CharStream, closure ATNConfigSet, reach ATNConfigSet, t int) { + // l is used to Skip processing for configs which have a lower priority + // than a config that already reached an accept state for the same rule + SkipAlt := ATNInvalidAltNumber + + for _, cfg := range closure.GetItems() { + currentAltReachedAcceptState := (cfg.GetAlt() == SkipAlt) + if currentAltReachedAcceptState && cfg.(*LexerATNConfig).passedThroughNonGreedyDecision { + continue + } + + if LexerATNSimulatorDebug { + + fmt.Printf("testing %s at %s\n", l.GetTokenName(t), cfg.String()) // l.recog, true)) + } + + for _, trans := range cfg.GetState().GetTransitions() { + target := l.getReachableTarget(trans, t) + if target != nil { + lexerActionExecutor := cfg.(*LexerATNConfig).lexerActionExecutor + if lexerActionExecutor != nil { + lexerActionExecutor = lexerActionExecutor.fixOffsetBeforeMatch(input.Index() - l.startIndex) + } + treatEOFAsEpsilon := (t == TokenEOF) + config := NewLexerATNConfig3(cfg.(*LexerATNConfig), target, lexerActionExecutor) + if l.closure(input, config, reach, + currentAltReachedAcceptState, true, treatEOFAsEpsilon) { + // any remaining configs for l alt have a lower priority + // than the one that just reached an accept state. + SkipAlt = cfg.GetAlt() + } + } + } + } +} + +func (l *LexerATNSimulator) accept(input CharStream, lexerActionExecutor *LexerActionExecutor, startIndex, index, line, charPos int) { + if LexerATNSimulatorDebug { + fmt.Printf("ACTION %v\n", lexerActionExecutor) + } + // seek to after last char in token + input.Seek(index) + l.Line = line + l.CharPositionInLine = charPos + if lexerActionExecutor != nil && l.recog != nil { + lexerActionExecutor.execute(l.recog, input, startIndex) + } +} + +func (l *LexerATNSimulator) getReachableTarget(trans Transition, t int) ATNState { + if trans.Matches(t, 0, LexerMaxCharValue) { + return trans.getTarget() + } + + return nil +} + +func (l *LexerATNSimulator) computeStartState(input CharStream, p ATNState) *OrderedATNConfigSet { + configs := NewOrderedATNConfigSet() + for i := 0; i < len(p.GetTransitions()); i++ { + target := p.GetTransitions()[i].getTarget() + cfg := NewLexerATNConfig6(target, i+1, BasePredictionContextEMPTY) + l.closure(input, cfg, configs, false, false, false) + } + + return configs +} + +// Since the alternatives within any lexer decision are ordered by +// preference, l method stops pursuing the closure as soon as an accept +// state is reached. After the first accept state is reached by depth-first +// search from {@code config}, all other (potentially reachable) states for +// l rule would have a lower priority. +// +// @return {@code true} if an accept state is reached, otherwise +// {@code false}. +func (l *LexerATNSimulator) closure(input CharStream, config *LexerATNConfig, configs ATNConfigSet, + currentAltReachedAcceptState, speculative, treatEOFAsEpsilon bool) bool { + + if LexerATNSimulatorDebug { + fmt.Println("closure(" + config.String() + ")") // config.String(l.recog, true) + ")") + } + + _, ok := config.state.(*RuleStopState) + if ok { + + if LexerATNSimulatorDebug { + if l.recog != nil { + fmt.Printf("closure at %s rule stop %s\n", l.recog.GetRuleNames()[config.state.GetRuleIndex()], config) + } else { + fmt.Printf("closure at rule stop %s\n", config) + } + } + + if config.context == nil || config.context.hasEmptyPath() { + if config.context == nil || config.context.isEmpty() { + configs.Add(config, nil) + return true + } + + configs.Add(NewLexerATNConfig2(config, config.state, BasePredictionContextEMPTY), nil) + currentAltReachedAcceptState = true + } + if config.context != nil && !config.context.isEmpty() { + for i := 0; i < config.context.length(); i++ { + if config.context.getReturnState(i) != BasePredictionContextEmptyReturnState { + newContext := config.context.GetParent(i) // "pop" return state + returnState := l.atn.states[config.context.getReturnState(i)] + cfg := NewLexerATNConfig2(config, returnState, newContext) + currentAltReachedAcceptState = l.closure(input, cfg, configs, currentAltReachedAcceptState, speculative, treatEOFAsEpsilon) + } + } + } + return currentAltReachedAcceptState + } + // optimization + if !config.state.GetEpsilonOnlyTransitions() { + if !currentAltReachedAcceptState || !config.passedThroughNonGreedyDecision { + configs.Add(config, nil) + } + } + for j := 0; j < len(config.state.GetTransitions()); j++ { + trans := config.state.GetTransitions()[j] + cfg := l.getEpsilonTarget(input, config, trans, configs, speculative, treatEOFAsEpsilon) + if cfg != nil { + currentAltReachedAcceptState = l.closure(input, cfg, configs, + currentAltReachedAcceptState, speculative, treatEOFAsEpsilon) + } + } + return currentAltReachedAcceptState +} + +// side-effect: can alter configs.hasSemanticContext +func (l *LexerATNSimulator) getEpsilonTarget(input CharStream, config *LexerATNConfig, trans Transition, + configs ATNConfigSet, speculative, treatEOFAsEpsilon bool) *LexerATNConfig { + + var cfg *LexerATNConfig + + if trans.getSerializationType() == TransitionRULE { + + rt := trans.(*RuleTransition) + newContext := SingletonBasePredictionContextCreate(config.context, rt.followState.GetStateNumber()) + cfg = NewLexerATNConfig2(config, trans.getTarget(), newContext) + + } else if trans.getSerializationType() == TransitionPRECEDENCE { + panic("Precedence predicates are not supported in lexers.") + } else if trans.getSerializationType() == TransitionPREDICATE { + // Track traversing semantic predicates. If we traverse, + // we cannot add a DFA state for l "reach" computation + // because the DFA would not test the predicate again in the + // future. Rather than creating collections of semantic predicates + // like v3 and testing them on prediction, v4 will test them on the + // fly all the time using the ATN not the DFA. This is slower but + // semantically it's not used that often. One of the key elements to + // l predicate mechanism is not adding DFA states that see + // predicates immediately afterwards in the ATN. For example, + + // a : ID {p1}? | ID {p2}? + + // should create the start state for rule 'a' (to save start state + // competition), but should not create target of ID state. The + // collection of ATN states the following ID references includes + // states reached by traversing predicates. Since l is when we + // test them, we cannot cash the DFA state target of ID. + + pt := trans.(*PredicateTransition) + + if LexerATNSimulatorDebug { + fmt.Println("EVAL rule " + strconv.Itoa(trans.(*PredicateTransition).ruleIndex) + ":" + strconv.Itoa(pt.predIndex)) + } + configs.SetHasSemanticContext(true) + if l.evaluatePredicate(input, pt.ruleIndex, pt.predIndex, speculative) { + cfg = NewLexerATNConfig4(config, trans.getTarget()) + } + } else if trans.getSerializationType() == TransitionACTION { + if config.context == nil || config.context.hasEmptyPath() { + // execute actions anywhere in the start rule for a token. + // + // TODO: if the entry rule is invoked recursively, some + // actions may be executed during the recursive call. The + // problem can appear when hasEmptyPath() is true but + // isEmpty() is false. In l case, the config needs to be + // split into two contexts - one with just the empty path + // and another with everything but the empty path. + // Unfortunately, the current algorithm does not allow + // getEpsilonTarget to return two configurations, so + // additional modifications are needed before we can support + // the split operation. + lexerActionExecutor := LexerActionExecutorappend(config.lexerActionExecutor, l.atn.lexerActions[trans.(*ActionTransition).actionIndex]) + cfg = NewLexerATNConfig3(config, trans.getTarget(), lexerActionExecutor) + } else { + // ignore actions in referenced rules + cfg = NewLexerATNConfig4(config, trans.getTarget()) + } + } else if trans.getSerializationType() == TransitionEPSILON { + cfg = NewLexerATNConfig4(config, trans.getTarget()) + } else if trans.getSerializationType() == TransitionATOM || + trans.getSerializationType() == TransitionRANGE || + trans.getSerializationType() == TransitionSET { + if treatEOFAsEpsilon { + if trans.Matches(TokenEOF, 0, LexerMaxCharValue) { + cfg = NewLexerATNConfig4(config, trans.getTarget()) + } + } + } + return cfg +} + +// Evaluate a predicate specified in the lexer. +// +//If {@code speculative} is {@code true}, l method was called before +// {@link //consume} for the Matched character. This method should call +// {@link //consume} before evaluating the predicate to ensure position +// sensitive values, including {@link Lexer//GetText}, {@link Lexer//GetLine}, +// and {@link Lexer//getcolumn}, properly reflect the current +// lexer state. This method should restore {@code input} and the simulator +// to the original state before returning (i.e. undo the actions made by the +// call to {@link //consume}.
+// +// @param input The input stream. +// @param ruleIndex The rule containing the predicate. +// @param predIndex The index of the predicate within the rule. +// @param speculative {@code true} if the current index in {@code input} is +// one character before the predicate's location. +// +// @return {@code true} if the specified predicate evaluates to +// {@code true}. +// / +func (l *LexerATNSimulator) evaluatePredicate(input CharStream, ruleIndex, predIndex int, speculative bool) bool { + // assume true if no recognizer was provided + if l.recog == nil { + return true + } + if !speculative { + return l.recog.Sempred(nil, ruleIndex, predIndex) + } + savedcolumn := l.CharPositionInLine + savedLine := l.Line + index := input.Index() + marker := input.Mark() + + defer func() { + l.CharPositionInLine = savedcolumn + l.Line = savedLine + input.Seek(index) + input.Release(marker) + }() + + l.Consume(input) + return l.recog.Sempred(nil, ruleIndex, predIndex) +} + +func (l *LexerATNSimulator) captureSimState(settings *SimState, input CharStream, dfaState *DFAState) { + settings.index = input.Index() + settings.line = l.Line + settings.column = l.CharPositionInLine + settings.dfaState = dfaState +} + +func (l *LexerATNSimulator) addDFAEdge(from *DFAState, tk int, to *DFAState, cfgs ATNConfigSet) *DFAState { + if to == nil && cfgs != nil { + // leading to l call, ATNConfigSet.hasSemanticContext is used as a + // marker indicating dynamic predicate evaluation makes l edge + // dependent on the specific input sequence, so the static edge in the + // DFA should be omitted. The target DFAState is still created since + // execATN has the ability to reSynchronize with the DFA state cache + // following the predicate evaluation step. + // + // TJP notes: next time through the DFA, we see a pred again and eval. + // If that gets us to a previously created (but dangling) DFA + // state, we can continue in pure DFA mode from there. + // / + suppressEdge := cfgs.HasSemanticContext() + cfgs.SetHasSemanticContext(false) + + to = l.addDFAState(cfgs, true) + + if suppressEdge { + return to + } + } + // add the edge + if tk < LexerATNSimulatorMinDFAEdge || tk > LexerATNSimulatorMaxDFAEdge { + // Only track edges within the DFA bounds + return to + } + if LexerATNSimulatorDebug { + fmt.Println("EDGE " + from.String() + " -> " + to.String() + " upon " + strconv.Itoa(tk)) + } + l.atn.edgeMu.Lock() + defer l.atn.edgeMu.Unlock() + if from.getEdges() == nil { + // make room for tokens 1..n and -1 masquerading as index 0 + from.setEdges(make([]*DFAState, LexerATNSimulatorMaxDFAEdge-LexerATNSimulatorMinDFAEdge+1)) + } + from.setIthEdge(tk-LexerATNSimulatorMinDFAEdge, to) // connect + + return to +} + +// Add a NewDFA state if there isn't one with l set of +// configurations already. This method also detects the first +// configuration containing an ATN rule stop state. Later, when +// traversing the DFA, we will know which rule to accept. +func (l *LexerATNSimulator) addDFAState(configs ATNConfigSet, suppressEdge bool) *DFAState { + + proposed := NewDFAState(-1, configs) + var firstConfigWithRuleStopState ATNConfig + + for _, cfg := range configs.GetItems() { + + _, ok := cfg.GetState().(*RuleStopState) + + if ok { + firstConfigWithRuleStopState = cfg + break + } + } + if firstConfigWithRuleStopState != nil { + proposed.isAcceptState = true + proposed.lexerActionExecutor = firstConfigWithRuleStopState.(*LexerATNConfig).lexerActionExecutor + proposed.setPrediction(l.atn.ruleToTokenType[firstConfigWithRuleStopState.GetState().GetRuleIndex()]) + } + dfa := l.decisionToDFA[l.mode] + + l.atn.stateMu.Lock() + defer l.atn.stateMu.Unlock() + existing, present := dfa.states.Get(proposed) + if present { + + // This state was already present, so just return it. + // + proposed = existing + } else { + + // We need to add the new state + // + proposed.stateNumber = dfa.states.Len() + configs.SetReadOnly(true) + proposed.configs = configs + dfa.states.Put(proposed) + } + if !suppressEdge { + dfa.setS0(proposed) + } + return proposed +} + +func (l *LexerATNSimulator) getDFA(mode int) *DFA { + return l.decisionToDFA[mode] +} + +// Get the text Matched so far for the current token. +func (l *LexerATNSimulator) GetText(input CharStream) string { + // index is first lookahead char, don't include. + return input.GetTextFromInterval(NewInterval(l.startIndex, input.Index()-1)) +} + +func (l *LexerATNSimulator) Consume(input CharStream) { + curChar := input.LA(1) + if curChar == int('\n') { + l.Line++ + l.CharPositionInLine = 0 + } else { + l.CharPositionInLine++ + } + input.Consume() +} + +func (l *LexerATNSimulator) GetCharPositionInLine() int { + return l.CharPositionInLine +} + +func (l *LexerATNSimulator) GetLine() int { + return l.Line +} + +func (l *LexerATNSimulator) GetTokenName(tt int) string { + if tt == -1 { + return "EOF" + } + + var sb strings.Builder + sb.Grow(6) + sb.WriteByte('\'') + sb.WriteRune(rune(tt)) + sb.WriteByte('\'') + + return sb.String() +} + +func resetSimState(sim *SimState) { + sim.index = -1 + sim.line = 0 + sim.column = -1 + sim.dfaState = nil +} + +type SimState struct { + index int + line int + column int + dfaState *DFAState +} + +func NewSimState() *SimState { + s := new(SimState) + resetSimState(s) + return s +} + +func (s *SimState) reset() { + resetSimState(s) +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/ll1_analyzer.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/ll1_analyzer.go index 76689615a6..50a617fde6 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/ll1_analyzer.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/ll1_analyzer.go @@ -1,216 +1,216 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -type LL1Analyzer struct { - atn *ATN -} - -func NewLL1Analyzer(atn *ATN) *LL1Analyzer { - la := new(LL1Analyzer) - la.atn = atn - return la -} - -// - Special value added to the lookahead sets to indicate that we hit -// a predicate during analysis if {@code seeThruPreds==false}. -// -// / -const ( - LL1AnalyzerHitPred = TokenInvalidType -) - -// * -// Calculates the SLL(1) expected lookahead set for each outgoing transition -// of an {@link ATNState}. The returned array has one element for each -// outgoing transition in {@code s}. If the closure from transition -// i leads to a semantic predicate before Matching a symbol, the -// element at index i of the result will be {@code nil}. -// -// @param s the ATN state -// @return the expected symbols for each outgoing transition of {@code s}. -func (la *LL1Analyzer) getDecisionLookahead(s ATNState) []*IntervalSet { - if s == nil { - return nil - } - count := len(s.GetTransitions()) - look := make([]*IntervalSet, count) - for alt := 0; alt < count; alt++ { - look[alt] = NewIntervalSet() - lookBusy := NewJStore[ATNConfig, Comparator[ATNConfig]](aConfEqInst) - seeThruPreds := false // fail to get lookahead upon pred - la.look1(s.GetTransitions()[alt].getTarget(), nil, BasePredictionContextEMPTY, look[alt], lookBusy, NewBitSet(), seeThruPreds, false) - // Wipe out lookahead for la alternative if we found nothing - // or we had a predicate when we !seeThruPreds - if look[alt].length() == 0 || look[alt].contains(LL1AnalyzerHitPred) { - look[alt] = nil - } - } - return look -} - -// * -// Compute set of tokens that can follow {@code s} in the ATN in the -// specified {@code ctx}. -// -//If {@code ctx} is {@code nil} and the end of the rule containing -// {@code s} is reached, {@link Token//EPSILON} is added to the result set. -// If {@code ctx} is not {@code nil} and the end of the outermost rule is -// reached, {@link Token//EOF} is added to the result set.
-// -// @param s the ATN state -// @param stopState the ATN state to stop at. This can be a -// {@link BlockEndState} to detect epsilon paths through a closure. -// @param ctx the complete parser context, or {@code nil} if the context -// should be ignored -// -// @return The set of tokens that can follow {@code s} in the ATN in the -// specified {@code ctx}. -// / -func (la *LL1Analyzer) Look(s, stopState ATNState, ctx RuleContext) *IntervalSet { - r := NewIntervalSet() - seeThruPreds := true // ignore preds get all lookahead - var lookContext PredictionContext - if ctx != nil { - lookContext = predictionContextFromRuleContext(s.GetATN(), ctx) - } - la.look1(s, stopState, lookContext, r, NewJStore[ATNConfig, Comparator[ATNConfig]](aConfEqInst), NewBitSet(), seeThruPreds, true) - return r -} - -//* -// Compute set of tokens that can follow {@code s} in the ATN in the -// specified {@code ctx}. -// -//If {@code ctx} is {@code nil} and {@code stopState} or the end of the -// rule containing {@code s} is reached, {@link Token//EPSILON} is added to -// the result set. If {@code ctx} is not {@code nil} and {@code addEOF} is -// {@code true} and {@code stopState} or the end of the outermost rule is -// reached, {@link Token//EOF} is added to the result set.
-// -// @param s the ATN state. -// @param stopState the ATN state to stop at. This can be a -// {@link BlockEndState} to detect epsilon paths through a closure. -// @param ctx The outer context, or {@code nil} if the outer context should -// not be used. -// @param look The result lookahead set. -// @param lookBusy A set used for preventing epsilon closures in the ATN -// from causing a stack overflow. Outside code should pass -// {@code NewSetIf {@code ctx} is {@code nil} and the end of the rule containing +// {@code s} is reached, {@link Token//EPSILON} is added to the result set. +// If {@code ctx} is not {@code nil} and the end of the outermost rule is +// reached, {@link Token//EOF} is added to the result set.
+// +// @param s the ATN state +// @param stopState the ATN state to stop at. This can be a +// {@link BlockEndState} to detect epsilon paths through a closure. +// @param ctx the complete parser context, or {@code nil} if the context +// should be ignored +// +// @return The set of tokens that can follow {@code s} in the ATN in the +// specified {@code ctx}. +// / +func (la *LL1Analyzer) Look(s, stopState ATNState, ctx RuleContext) *IntervalSet { + r := NewIntervalSet() + seeThruPreds := true // ignore preds get all lookahead + var lookContext PredictionContext + if ctx != nil { + lookContext = predictionContextFromRuleContext(s.GetATN(), ctx) + } + la.look1(s, stopState, lookContext, r, NewJStore[ATNConfig, Comparator[ATNConfig]](aConfEqInst), NewBitSet(), seeThruPreds, true) + return r +} + +//* +// Compute set of tokens that can follow {@code s} in the ATN in the +// specified {@code ctx}. +// +//If {@code ctx} is {@code nil} and {@code stopState} or the end of the +// rule containing {@code s} is reached, {@link Token//EPSILON} is added to +// the result set. If {@code ctx} is not {@code nil} and {@code addEOF} is +// {@code true} and {@code stopState} or the end of the outermost rule is +// reached, {@link Token//EOF} is added to the result set.
+// +// @param s the ATN state. +// @param stopState the ATN state to stop at. This can be a +// {@link BlockEndState} to detect epsilon paths through a closure. +// @param ctx The outer context, or {@code nil} if the outer context should +// not be used. +// @param look The result lookahead set. +// @param lookBusy A set used for preventing epsilon closures in the ATN +// from causing a stack overflow. Outside code should pass +// {@code NewSetIf the symbol type does not Match, -// {@link ANTLRErrorStrategy//recoverInline} is called on the current error -// strategy to attempt recovery. If {@link //getBuildParseTree} is -// {@code true} and the token index of the symbol returned by -// {@link ANTLRErrorStrategy//recoverInline} is -1, the symbol is added to -// the parse tree by calling {@link ParserRuleContext//addErrorNode}.
-// -// @param ttype the token type to Match -// @return the Matched symbol -// @panics RecognitionException if the current input symbol did not Match -// {@code ttype} and the error strategy could not recover from the -// mismatched symbol - -func (p *BaseParser) Match(ttype int) Token { - - t := p.GetCurrentToken() - - if t.GetTokenType() == ttype { - p.errHandler.ReportMatch(p) - p.Consume() - } else { - t = p.errHandler.RecoverInline(p) - if p.BuildParseTrees && t.GetTokenIndex() == -1 { - // we must have conjured up a Newtoken during single token - // insertion - // if it's not the current symbol - p.ctx.AddErrorNode(t) - } - } - - return t -} - -// Match current input symbol as a wildcard. If the symbol type Matches -// (i.e. has a value greater than 0), {@link ANTLRErrorStrategy//ReportMatch} -// and {@link //consume} are called to complete the Match process. -// -//If the symbol type does not Match, -// {@link ANTLRErrorStrategy//recoverInline} is called on the current error -// strategy to attempt recovery. If {@link //getBuildParseTree} is -// {@code true} and the token index of the symbol returned by -// {@link ANTLRErrorStrategy//recoverInline} is -1, the symbol is added to -// the parse tree by calling {@link ParserRuleContext//addErrorNode}.
-// -// @return the Matched symbol -// @panics RecognitionException if the current input symbol did not Match -// a wildcard and the error strategy could not recover from the mismatched -// symbol - -func (p *BaseParser) MatchWildcard() Token { - t := p.GetCurrentToken() - if t.GetTokenType() > 0 { - p.errHandler.ReportMatch(p) - p.Consume() - } else { - t = p.errHandler.RecoverInline(p) - if p.BuildParseTrees && t.GetTokenIndex() == -1 { - // we must have conjured up a Newtoken during single token - // insertion - // if it's not the current symbol - p.ctx.AddErrorNode(t) - } - } - return t -} - -func (p *BaseParser) GetParserRuleContext() ParserRuleContext { - return p.ctx -} - -func (p *BaseParser) SetParserRuleContext(v ParserRuleContext) { - p.ctx = v -} - -func (p *BaseParser) GetParseListeners() []ParseTreeListener { - if p.parseListeners == nil { - return make([]ParseTreeListener, 0) - } - return p.parseListeners -} - -// Registers {@code listener} to receive events during the parsing process. -// -//To support output-preserving grammar transformations (including but not -// limited to left-recursion removal, automated left-factoring, and -// optimized code generation), calls to listener methods during the parse -// may differ substantially from calls made by -// {@link ParseTreeWalker//DEFAULT} used after the parse is complete. In -// particular, rule entry and exit events may occur in a different order -// during the parse than after the parser. In addition, calls to certain -// rule entry methods may be omitted.
-// -//With the following specific exceptions, calls to listener events are -// deterministic, i.e. for identical input the calls to listener -// methods will be the same.
-// -//-
-//
- Alterations to the grammar used to generate code may change the -// behavior of the listener calls. -//
- Alterations to the command line options passed to ANTLR 4 when -// generating the parser may change the behavior of the listener calls. -//
- Changing the version of the ANTLR Tool used to generate the parser -// may change the behavior of the listener calls. -//
If {@code listener} is {@code nil} or has not been added as a parse -// listener, p.method does nothing.
-// @param listener the listener to remove -func (p *BaseParser) RemoveParseListener(listener ParseTreeListener) { - - if p.parseListeners != nil { - - idx := -1 - for i, v := range p.parseListeners { - if v == listener { - idx = i - break - } - } - - if idx == -1 { - return - } - - // remove the listener from the slice - p.parseListeners = append(p.parseListeners[0:idx], p.parseListeners[idx+1:]...) - - if len(p.parseListeners) == 0 { - p.parseListeners = nil - } - } -} - -// Remove all parse listeners. -func (p *BaseParser) removeParseListeners() { - p.parseListeners = nil -} - -// Notify any parse listeners of an enter rule event. -func (p *BaseParser) TriggerEnterRuleEvent() { - if p.parseListeners != nil { - ctx := p.ctx - for _, listener := range p.parseListeners { - listener.EnterEveryRule(ctx) - ctx.EnterRule(listener) - } - } -} - -// Notify any parse listeners of an exit rule event. -// -// @see //addParseListener -func (p *BaseParser) TriggerExitRuleEvent() { - if p.parseListeners != nil { - // reverse order walk of listeners - ctx := p.ctx - l := len(p.parseListeners) - 1 - - for i := range p.parseListeners { - listener := p.parseListeners[l-i] - ctx.ExitRule(listener) - listener.ExitEveryRule(ctx) - } - } -} - -func (p *BaseParser) GetInterpreter() *ParserATNSimulator { - return p.Interpreter -} - -func (p *BaseParser) GetATN() *ATN { - return p.Interpreter.atn -} - -func (p *BaseParser) GetTokenFactory() TokenFactory { - return p.input.GetTokenSource().GetTokenFactory() -} - -// Tell our token source and error strategy about a Newway to create tokens.// -func (p *BaseParser) setTokenFactory(factory TokenFactory) { - p.input.GetTokenSource().setTokenFactory(factory) -} - -// The ATN with bypass alternatives is expensive to create so we create it -// lazily. -// -// @panics UnsupportedOperationException if the current parser does not -// implement the {@link //getSerializedATN()} method. -func (p *BaseParser) GetATNWithBypassAlts() { - - // TODO - panic("Not implemented!") - - // serializedAtn := p.getSerializedATN() - // if (serializedAtn == nil) { - // panic("The current parser does not support an ATN with bypass alternatives.") - // } - // result := p.bypassAltsAtnCache[serializedAtn] - // if (result == nil) { - // deserializationOptions := NewATNDeserializationOptions(nil) - // deserializationOptions.generateRuleBypassTransitions = true - // result = NewATNDeserializer(deserializationOptions).deserialize(serializedAtn) - // p.bypassAltsAtnCache[serializedAtn] = result - // } - // return result -} - -// The preferred method of getting a tree pattern. For example, here's a -// sample use: -// -//
-// ParseTree t = parser.expr()
-// ParseTreePattern p = parser.compileParseTreePattern("<ID>+0",
-// MyParser.RULE_expr)
-// ParseTreeMatch m = p.Match(t)
-// String id = m.Get("ID")
-//
-
-func (p *BaseParser) compileParseTreePattern(pattern, patternRuleIndex, lexer Lexer) {
-
- panic("NewParseTreePatternMatcher not implemented!")
- //
- // if (lexer == nil) {
- // if (p.GetTokenStream() != nil) {
- // tokenSource := p.GetTokenStream().GetTokenSource()
- // if _, ok := tokenSource.(ILexer); ok {
- // lexer = tokenSource
- // }
- // }
- // }
- // if (lexer == nil) {
- // panic("Parser can't discover a lexer to use")
- // }
-
- // m := NewParseTreePatternMatcher(lexer, p)
- // return m.compile(pattern, patternRuleIndex)
-}
-
-func (p *BaseParser) GetInputStream() IntStream {
- return p.GetTokenStream()
-}
-
-func (p *BaseParser) SetInputStream(input TokenStream) {
- p.SetTokenStream(input)
-}
-
-func (p *BaseParser) GetTokenStream() TokenStream {
- return p.input
-}
-
-// Set the token stream and reset the parser.//
-func (p *BaseParser) SetTokenStream(input TokenStream) {
- p.input = nil
- p.reset()
- p.input = input
-}
-
-// Match needs to return the current input symbol, which gets put
-// into the label for the associated token ref e.g., x=ID.
-func (p *BaseParser) GetCurrentToken() Token {
- return p.input.LT(1)
-}
-
-func (p *BaseParser) NotifyErrorListeners(msg string, offendingToken Token, err RecognitionException) {
- if offendingToken == nil {
- offendingToken = p.GetCurrentToken()
- }
- p._SyntaxErrors++
- line := offendingToken.GetLine()
- column := offendingToken.GetColumn()
- listener := p.GetErrorListenerDispatch()
- listener.SyntaxError(p, offendingToken, line, column, msg, err)
-}
-
-func (p *BaseParser) Consume() Token {
- o := p.GetCurrentToken()
- if o.GetTokenType() != TokenEOF {
- p.GetInputStream().Consume()
- }
- hasListener := p.parseListeners != nil && len(p.parseListeners) > 0
- if p.BuildParseTrees || hasListener {
- if p.errHandler.InErrorRecoveryMode(p) {
- node := p.ctx.AddErrorNode(o)
- if p.parseListeners != nil {
- for _, l := range p.parseListeners {
- l.VisitErrorNode(node)
- }
- }
-
- } else {
- node := p.ctx.AddTokenNode(o)
- if p.parseListeners != nil {
- for _, l := range p.parseListeners {
- l.VisitTerminal(node)
- }
- }
- }
- // node.invokingState = p.state
- }
-
- return o
-}
-
-func (p *BaseParser) addContextToParseTree() {
- // add current context to parent if we have a parent
- if p.ctx.GetParent() != nil {
- p.ctx.GetParent().(ParserRuleContext).AddChild(p.ctx)
- }
-}
-
-func (p *BaseParser) EnterRule(localctx ParserRuleContext, state, ruleIndex int) {
- p.SetState(state)
- p.ctx = localctx
- p.ctx.SetStart(p.input.LT(1))
- if p.BuildParseTrees {
- p.addContextToParseTree()
- }
- if p.parseListeners != nil {
- p.TriggerEnterRuleEvent()
- }
-}
-
-func (p *BaseParser) ExitRule() {
- p.ctx.SetStop(p.input.LT(-1))
- // trigger event on ctx, before it reverts to parent
- if p.parseListeners != nil {
- p.TriggerExitRuleEvent()
- }
- p.SetState(p.ctx.GetInvokingState())
- if p.ctx.GetParent() != nil {
- p.ctx = p.ctx.GetParent().(ParserRuleContext)
- } else {
- p.ctx = nil
- }
-}
-
-func (p *BaseParser) EnterOuterAlt(localctx ParserRuleContext, altNum int) {
- localctx.SetAltNumber(altNum)
- // if we have Newlocalctx, make sure we replace existing ctx
- // that is previous child of parse tree
- if p.BuildParseTrees && p.ctx != localctx {
- if p.ctx.GetParent() != nil {
- p.ctx.GetParent().(ParserRuleContext).RemoveLastChild()
- p.ctx.GetParent().(ParserRuleContext).AddChild(localctx)
- }
- }
- p.ctx = localctx
-}
-
-// Get the precedence level for the top-most precedence rule.
-//
-// @return The precedence level for the top-most precedence rule, or -1 if
-// the parser context is not nested within a precedence rule.
-
-func (p *BaseParser) GetPrecedence() int {
- if len(p.precedenceStack) == 0 {
- return -1
- }
-
- return p.precedenceStack[len(p.precedenceStack)-1]
-}
-
-func (p *BaseParser) EnterRecursionRule(localctx ParserRuleContext, state, ruleIndex, precedence int) {
- p.SetState(state)
- p.precedenceStack.Push(precedence)
- p.ctx = localctx
- p.ctx.SetStart(p.input.LT(1))
- if p.parseListeners != nil {
- p.TriggerEnterRuleEvent() // simulates rule entry for
- // left-recursive rules
- }
-}
-
-//
-// Like {@link //EnterRule} but for recursive rules.
-
-func (p *BaseParser) PushNewRecursionContext(localctx ParserRuleContext, state, ruleIndex int) {
- previous := p.ctx
- previous.SetParent(localctx)
- previous.SetInvokingState(state)
- previous.SetStop(p.input.LT(-1))
-
- p.ctx = localctx
- p.ctx.SetStart(previous.GetStart())
- if p.BuildParseTrees {
- p.ctx.AddChild(previous)
- }
- if p.parseListeners != nil {
- p.TriggerEnterRuleEvent() // simulates rule entry for
- // left-recursive rules
- }
-}
-
-func (p *BaseParser) UnrollRecursionContexts(parentCtx ParserRuleContext) {
- p.precedenceStack.Pop()
- p.ctx.SetStop(p.input.LT(-1))
- retCtx := p.ctx // save current ctx (return value)
- // unroll so ctx is as it was before call to recursive method
- if p.parseListeners != nil {
- for p.ctx != parentCtx {
- p.TriggerExitRuleEvent()
- p.ctx = p.ctx.GetParent().(ParserRuleContext)
- }
- } else {
- p.ctx = parentCtx
- }
- // hook into tree
- retCtx.SetParent(parentCtx)
- if p.BuildParseTrees && parentCtx != nil {
- // add return ctx into invoking rule's tree
- parentCtx.AddChild(retCtx)
- }
-}
-
-func (p *BaseParser) GetInvokingContext(ruleIndex int) ParserRuleContext {
- ctx := p.ctx
- for ctx != nil {
- if ctx.GetRuleIndex() == ruleIndex {
- return ctx
- }
- ctx = ctx.GetParent().(ParserRuleContext)
- }
- return nil
-}
-
-func (p *BaseParser) Precpred(localctx RuleContext, precedence int) bool {
- return precedence >= p.precedenceStack[len(p.precedenceStack)-1]
-}
-
-func (p *BaseParser) inContext(context ParserRuleContext) bool {
- // TODO: useful in parser?
- return false
-}
-
-//
-// Checks whether or not {@code symbol} can follow the current state in the
-// ATN. The behavior of p.method is equivalent to the following, but is
-// implemented such that the complete context-sensitive follow set does not
-// need to be explicitly constructed.
-//
-// -// return getExpectedTokens().contains(symbol) -//-// -// @param symbol the symbol type to check -// @return {@code true} if {@code symbol} can follow the current state in -// the ATN, otherwise {@code false}. - -func (p *BaseParser) IsExpectedToken(symbol int) bool { - atn := p.Interpreter.atn - ctx := p.ctx - s := atn.states[p.state] - following := atn.NextTokens(s, nil) - if following.contains(symbol) { - return true - } - if !following.contains(TokenEpsilon) { - return false - } - for ctx != nil && ctx.GetInvokingState() >= 0 && following.contains(TokenEpsilon) { - invokingState := atn.states[ctx.GetInvokingState()] - rt := invokingState.GetTransitions()[0] - following = atn.NextTokens(rt.(*RuleTransition).followState, nil) - if following.contains(symbol) { - return true - } - ctx = ctx.GetParent().(ParserRuleContext) - } - if following.contains(TokenEpsilon) && symbol == TokenEOF { - return true - } - - return false -} - -// Computes the set of input symbols which could follow the current parser -// state and context, as given by {@link //GetState} and {@link //GetContext}, -// respectively. -// -// @see ATN//getExpectedTokens(int, RuleContext) -func (p *BaseParser) GetExpectedTokens() *IntervalSet { - return p.Interpreter.atn.getExpectedTokens(p.state, p.ctx) -} - -func (p *BaseParser) GetExpectedTokensWithinCurrentRule() *IntervalSet { - atn := p.Interpreter.atn - s := atn.states[p.state] - return atn.NextTokens(s, nil) -} - -// Get a rule's index (i.e., {@code RULE_ruleName} field) or -1 if not found.// -func (p *BaseParser) GetRuleIndex(ruleName string) int { - var ruleIndex, ok = p.GetRuleIndexMap()[ruleName] - if ok { - return ruleIndex - } - - return -1 -} - -// Return List<String> of the rule names in your parser instance -// leading up to a call to the current rule. You could override if -// you want more details such as the file/line info of where -// in the ATN a rule is invoked. -// -// this very useful for error messages. - -func (p *BaseParser) GetRuleInvocationStack(c ParserRuleContext) []string { - if c == nil { - c = p.ctx - } - stack := make([]string, 0) - for c != nil { - // compute what follows who invoked us - ruleIndex := c.GetRuleIndex() - if ruleIndex < 0 { - stack = append(stack, "n/a") - } else { - stack = append(stack, p.GetRuleNames()[ruleIndex]) - } - - vp := c.GetParent() - - if vp == nil { - break - } - - c = vp.(ParserRuleContext) - } - return stack -} - -// For debugging and other purposes.// -func (p *BaseParser) GetDFAStrings() string { - return fmt.Sprint(p.Interpreter.decisionToDFA) -} - -// For debugging and other purposes.// -func (p *BaseParser) DumpDFA() { - seenOne := false - for _, dfa := range p.Interpreter.decisionToDFA { - if dfa.states.Len() > 0 { - if seenOne { - fmt.Println() - } - fmt.Println("Decision " + strconv.Itoa(dfa.decision) + ":") - fmt.Print(dfa.String(p.LiteralNames, p.SymbolicNames)) - seenOne = true - } - } -} - -func (p *BaseParser) GetSourceName() string { - return p.GrammarFileName -} - -// During a parse is sometimes useful to listen in on the rule entry and exit -// events as well as token Matches. p.is for quick and dirty debugging. -func (p *BaseParser) SetTrace(trace *TraceListener) { - if trace == nil { - p.RemoveParseListener(p.tracer) - p.tracer = nil - } else { - if p.tracer != nil { - p.RemoveParseListener(p.tracer) - } - p.tracer = NewTraceListener(p) - p.AddParseListener(p.tracer) - } -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "fmt" + "strconv" +) + +type Parser interface { + Recognizer + + GetInterpreter() *ParserATNSimulator + + GetTokenStream() TokenStream + GetTokenFactory() TokenFactory + GetParserRuleContext() ParserRuleContext + SetParserRuleContext(ParserRuleContext) + Consume() Token + GetParseListeners() []ParseTreeListener + + GetErrorHandler() ErrorStrategy + SetErrorHandler(ErrorStrategy) + GetInputStream() IntStream + GetCurrentToken() Token + GetExpectedTokens() *IntervalSet + NotifyErrorListeners(string, Token, RecognitionException) + IsExpectedToken(int) bool + GetPrecedence() int + GetRuleInvocationStack(ParserRuleContext) []string +} + +type BaseParser struct { + *BaseRecognizer + + Interpreter *ParserATNSimulator + BuildParseTrees bool + + input TokenStream + errHandler ErrorStrategy + precedenceStack IntStack + ctx ParserRuleContext + + tracer *TraceListener + parseListeners []ParseTreeListener + _SyntaxErrors int +} + +// p.is all the parsing support code essentially most of it is error +// recovery stuff.// +func NewBaseParser(input TokenStream) *BaseParser { + + p := new(BaseParser) + + p.BaseRecognizer = NewBaseRecognizer() + + // The input stream. + p.input = nil + // The error handling strategy for the parser. The default value is a new + // instance of {@link DefaultErrorStrategy}. + p.errHandler = NewDefaultErrorStrategy() + p.precedenceStack = make([]int, 0) + p.precedenceStack.Push(0) + // The {@link ParserRuleContext} object for the currently executing rule. + // p.is always non-nil during the parsing process. + p.ctx = nil + // Specifies whether or not the parser should construct a parse tree during + // the parsing process. The default value is {@code true}. + p.BuildParseTrees = true + // When {@link //setTrace}{@code (true)} is called, a reference to the + // {@link TraceListener} is stored here so it can be easily removed in a + // later call to {@link //setTrace}{@code (false)}. The listener itself is + // implemented as a parser listener so p.field is not directly used by + // other parser methods. + p.tracer = nil + // The list of {@link ParseTreeListener} listeners registered to receive + // events during the parse. + p.parseListeners = nil + // The number of syntax errors Reported during parsing. p.value is + // incremented each time {@link //NotifyErrorListeners} is called. + p._SyntaxErrors = 0 + p.SetInputStream(input) + + return p +} + +// p.field maps from the serialized ATN string to the deserialized {@link +// ATN} with +// bypass alternatives. +// +// @see ATNDeserializationOptions//isGenerateRuleBypassTransitions() +var bypassAltsAtnCache = make(map[string]int) + +// reset the parser's state// +func (p *BaseParser) reset() { + if p.input != nil { + p.input.Seek(0) + } + p.errHandler.reset(p) + p.ctx = nil + p._SyntaxErrors = 0 + p.SetTrace(nil) + p.precedenceStack = make([]int, 0) + p.precedenceStack.Push(0) + if p.Interpreter != nil { + p.Interpreter.reset() + } +} + +func (p *BaseParser) GetErrorHandler() ErrorStrategy { + return p.errHandler +} + +func (p *BaseParser) SetErrorHandler(e ErrorStrategy) { + p.errHandler = e +} + +// Match current input symbol against {@code ttype}. If the symbol type +// Matches, {@link ANTLRErrorStrategy//ReportMatch} and {@link //consume} are +// called to complete the Match process. +// +//
If the symbol type does not Match, +// {@link ANTLRErrorStrategy//recoverInline} is called on the current error +// strategy to attempt recovery. If {@link //getBuildParseTree} is +// {@code true} and the token index of the symbol returned by +// {@link ANTLRErrorStrategy//recoverInline} is -1, the symbol is added to +// the parse tree by calling {@link ParserRuleContext//addErrorNode}.
+// +// @param ttype the token type to Match +// @return the Matched symbol +// @panics RecognitionException if the current input symbol did not Match +// {@code ttype} and the error strategy could not recover from the +// mismatched symbol + +func (p *BaseParser) Match(ttype int) Token { + + t := p.GetCurrentToken() + + if t.GetTokenType() == ttype { + p.errHandler.ReportMatch(p) + p.Consume() + } else { + t = p.errHandler.RecoverInline(p) + if p.BuildParseTrees && t.GetTokenIndex() == -1 { + // we must have conjured up a Newtoken during single token + // insertion + // if it's not the current symbol + p.ctx.AddErrorNode(t) + } + } + + return t +} + +// Match current input symbol as a wildcard. If the symbol type Matches +// (i.e. has a value greater than 0), {@link ANTLRErrorStrategy//ReportMatch} +// and {@link //consume} are called to complete the Match process. +// +//If the symbol type does not Match, +// {@link ANTLRErrorStrategy//recoverInline} is called on the current error +// strategy to attempt recovery. If {@link //getBuildParseTree} is +// {@code true} and the token index of the symbol returned by +// {@link ANTLRErrorStrategy//recoverInline} is -1, the symbol is added to +// the parse tree by calling {@link ParserRuleContext//addErrorNode}.
+// +// @return the Matched symbol +// @panics RecognitionException if the current input symbol did not Match +// a wildcard and the error strategy could not recover from the mismatched +// symbol + +func (p *BaseParser) MatchWildcard() Token { + t := p.GetCurrentToken() + if t.GetTokenType() > 0 { + p.errHandler.ReportMatch(p) + p.Consume() + } else { + t = p.errHandler.RecoverInline(p) + if p.BuildParseTrees && t.GetTokenIndex() == -1 { + // we must have conjured up a Newtoken during single token + // insertion + // if it's not the current symbol + p.ctx.AddErrorNode(t) + } + } + return t +} + +func (p *BaseParser) GetParserRuleContext() ParserRuleContext { + return p.ctx +} + +func (p *BaseParser) SetParserRuleContext(v ParserRuleContext) { + p.ctx = v +} + +func (p *BaseParser) GetParseListeners() []ParseTreeListener { + if p.parseListeners == nil { + return make([]ParseTreeListener, 0) + } + return p.parseListeners +} + +// Registers {@code listener} to receive events during the parsing process. +// +//To support output-preserving grammar transformations (including but not +// limited to left-recursion removal, automated left-factoring, and +// optimized code generation), calls to listener methods during the parse +// may differ substantially from calls made by +// {@link ParseTreeWalker//DEFAULT} used after the parse is complete. In +// particular, rule entry and exit events may occur in a different order +// during the parse than after the parser. In addition, calls to certain +// rule entry methods may be omitted.
+// +//With the following specific exceptions, calls to listener events are +// deterministic, i.e. for identical input the calls to listener +// methods will be the same.
+// +//-
+//
- Alterations to the grammar used to generate code may change the +// behavior of the listener calls. +//
- Alterations to the command line options passed to ANTLR 4 when +// generating the parser may change the behavior of the listener calls. +//
- Changing the version of the ANTLR Tool used to generate the parser +// may change the behavior of the listener calls. +//
If {@code listener} is {@code nil} or has not been added as a parse +// listener, p.method does nothing.
+// @param listener the listener to remove +func (p *BaseParser) RemoveParseListener(listener ParseTreeListener) { + + if p.parseListeners != nil { + + idx := -1 + for i, v := range p.parseListeners { + if v == listener { + idx = i + break + } + } + + if idx == -1 { + return + } + + // remove the listener from the slice + p.parseListeners = append(p.parseListeners[0:idx], p.parseListeners[idx+1:]...) + + if len(p.parseListeners) == 0 { + p.parseListeners = nil + } + } +} + +// Remove all parse listeners. +func (p *BaseParser) removeParseListeners() { + p.parseListeners = nil +} + +// Notify any parse listeners of an enter rule event. +func (p *BaseParser) TriggerEnterRuleEvent() { + if p.parseListeners != nil { + ctx := p.ctx + for _, listener := range p.parseListeners { + listener.EnterEveryRule(ctx) + ctx.EnterRule(listener) + } + } +} + +// Notify any parse listeners of an exit rule event. +// +// @see //addParseListener +func (p *BaseParser) TriggerExitRuleEvent() { + if p.parseListeners != nil { + // reverse order walk of listeners + ctx := p.ctx + l := len(p.parseListeners) - 1 + + for i := range p.parseListeners { + listener := p.parseListeners[l-i] + ctx.ExitRule(listener) + listener.ExitEveryRule(ctx) + } + } +} + +func (p *BaseParser) GetInterpreter() *ParserATNSimulator { + return p.Interpreter +} + +func (p *BaseParser) GetATN() *ATN { + return p.Interpreter.atn +} + +func (p *BaseParser) GetTokenFactory() TokenFactory { + return p.input.GetTokenSource().GetTokenFactory() +} + +// Tell our token source and error strategy about a Newway to create tokens.// +func (p *BaseParser) setTokenFactory(factory TokenFactory) { + p.input.GetTokenSource().setTokenFactory(factory) +} + +// The ATN with bypass alternatives is expensive to create so we create it +// lazily. +// +// @panics UnsupportedOperationException if the current parser does not +// implement the {@link //getSerializedATN()} method. +func (p *BaseParser) GetATNWithBypassAlts() { + + // TODO + panic("Not implemented!") + + // serializedAtn := p.getSerializedATN() + // if (serializedAtn == nil) { + // panic("The current parser does not support an ATN with bypass alternatives.") + // } + // result := p.bypassAltsAtnCache[serializedAtn] + // if (result == nil) { + // deserializationOptions := NewATNDeserializationOptions(nil) + // deserializationOptions.generateRuleBypassTransitions = true + // result = NewATNDeserializer(deserializationOptions).deserialize(serializedAtn) + // p.bypassAltsAtnCache[serializedAtn] = result + // } + // return result +} + +// The preferred method of getting a tree pattern. For example, here's a +// sample use: +// +//
+// ParseTree t = parser.expr()
+// ParseTreePattern p = parser.compileParseTreePattern("<ID>+0",
+// MyParser.RULE_expr)
+// ParseTreeMatch m = p.Match(t)
+// String id = m.Get("ID")
+//
+
+func (p *BaseParser) compileParseTreePattern(pattern, patternRuleIndex, lexer Lexer) {
+
+ panic("NewParseTreePatternMatcher not implemented!")
+ //
+ // if (lexer == nil) {
+ // if (p.GetTokenStream() != nil) {
+ // tokenSource := p.GetTokenStream().GetTokenSource()
+ // if _, ok := tokenSource.(ILexer); ok {
+ // lexer = tokenSource
+ // }
+ // }
+ // }
+ // if (lexer == nil) {
+ // panic("Parser can't discover a lexer to use")
+ // }
+
+ // m := NewParseTreePatternMatcher(lexer, p)
+ // return m.compile(pattern, patternRuleIndex)
+}
+
+func (p *BaseParser) GetInputStream() IntStream {
+ return p.GetTokenStream()
+}
+
+func (p *BaseParser) SetInputStream(input TokenStream) {
+ p.SetTokenStream(input)
+}
+
+func (p *BaseParser) GetTokenStream() TokenStream {
+ return p.input
+}
+
+// Set the token stream and reset the parser.//
+func (p *BaseParser) SetTokenStream(input TokenStream) {
+ p.input = nil
+ p.reset()
+ p.input = input
+}
+
+// Match needs to return the current input symbol, which gets put
+// into the label for the associated token ref e.g., x=ID.
+func (p *BaseParser) GetCurrentToken() Token {
+ return p.input.LT(1)
+}
+
+func (p *BaseParser) NotifyErrorListeners(msg string, offendingToken Token, err RecognitionException) {
+ if offendingToken == nil {
+ offendingToken = p.GetCurrentToken()
+ }
+ p._SyntaxErrors++
+ line := offendingToken.GetLine()
+ column := offendingToken.GetColumn()
+ listener := p.GetErrorListenerDispatch()
+ listener.SyntaxError(p, offendingToken, line, column, msg, err)
+}
+
+func (p *BaseParser) Consume() Token {
+ o := p.GetCurrentToken()
+ if o.GetTokenType() != TokenEOF {
+ p.GetInputStream().Consume()
+ }
+ hasListener := p.parseListeners != nil && len(p.parseListeners) > 0
+ if p.BuildParseTrees || hasListener {
+ if p.errHandler.InErrorRecoveryMode(p) {
+ node := p.ctx.AddErrorNode(o)
+ if p.parseListeners != nil {
+ for _, l := range p.parseListeners {
+ l.VisitErrorNode(node)
+ }
+ }
+
+ } else {
+ node := p.ctx.AddTokenNode(o)
+ if p.parseListeners != nil {
+ for _, l := range p.parseListeners {
+ l.VisitTerminal(node)
+ }
+ }
+ }
+ // node.invokingState = p.state
+ }
+
+ return o
+}
+
+func (p *BaseParser) addContextToParseTree() {
+ // add current context to parent if we have a parent
+ if p.ctx.GetParent() != nil {
+ p.ctx.GetParent().(ParserRuleContext).AddChild(p.ctx)
+ }
+}
+
+func (p *BaseParser) EnterRule(localctx ParserRuleContext, state, ruleIndex int) {
+ p.SetState(state)
+ p.ctx = localctx
+ p.ctx.SetStart(p.input.LT(1))
+ if p.BuildParseTrees {
+ p.addContextToParseTree()
+ }
+ if p.parseListeners != nil {
+ p.TriggerEnterRuleEvent()
+ }
+}
+
+func (p *BaseParser) ExitRule() {
+ p.ctx.SetStop(p.input.LT(-1))
+ // trigger event on ctx, before it reverts to parent
+ if p.parseListeners != nil {
+ p.TriggerExitRuleEvent()
+ }
+ p.SetState(p.ctx.GetInvokingState())
+ if p.ctx.GetParent() != nil {
+ p.ctx = p.ctx.GetParent().(ParserRuleContext)
+ } else {
+ p.ctx = nil
+ }
+}
+
+func (p *BaseParser) EnterOuterAlt(localctx ParserRuleContext, altNum int) {
+ localctx.SetAltNumber(altNum)
+ // if we have Newlocalctx, make sure we replace existing ctx
+ // that is previous child of parse tree
+ if p.BuildParseTrees && p.ctx != localctx {
+ if p.ctx.GetParent() != nil {
+ p.ctx.GetParent().(ParserRuleContext).RemoveLastChild()
+ p.ctx.GetParent().(ParserRuleContext).AddChild(localctx)
+ }
+ }
+ p.ctx = localctx
+}
+
+// Get the precedence level for the top-most precedence rule.
+//
+// @return The precedence level for the top-most precedence rule, or -1 if
+// the parser context is not nested within a precedence rule.
+
+func (p *BaseParser) GetPrecedence() int {
+ if len(p.precedenceStack) == 0 {
+ return -1
+ }
+
+ return p.precedenceStack[len(p.precedenceStack)-1]
+}
+
+func (p *BaseParser) EnterRecursionRule(localctx ParserRuleContext, state, ruleIndex, precedence int) {
+ p.SetState(state)
+ p.precedenceStack.Push(precedence)
+ p.ctx = localctx
+ p.ctx.SetStart(p.input.LT(1))
+ if p.parseListeners != nil {
+ p.TriggerEnterRuleEvent() // simulates rule entry for
+ // left-recursive rules
+ }
+}
+
+//
+// Like {@link //EnterRule} but for recursive rules.
+
+func (p *BaseParser) PushNewRecursionContext(localctx ParserRuleContext, state, ruleIndex int) {
+ previous := p.ctx
+ previous.SetParent(localctx)
+ previous.SetInvokingState(state)
+ previous.SetStop(p.input.LT(-1))
+
+ p.ctx = localctx
+ p.ctx.SetStart(previous.GetStart())
+ if p.BuildParseTrees {
+ p.ctx.AddChild(previous)
+ }
+ if p.parseListeners != nil {
+ p.TriggerEnterRuleEvent() // simulates rule entry for
+ // left-recursive rules
+ }
+}
+
+func (p *BaseParser) UnrollRecursionContexts(parentCtx ParserRuleContext) {
+ p.precedenceStack.Pop()
+ p.ctx.SetStop(p.input.LT(-1))
+ retCtx := p.ctx // save current ctx (return value)
+ // unroll so ctx is as it was before call to recursive method
+ if p.parseListeners != nil {
+ for p.ctx != parentCtx {
+ p.TriggerExitRuleEvent()
+ p.ctx = p.ctx.GetParent().(ParserRuleContext)
+ }
+ } else {
+ p.ctx = parentCtx
+ }
+ // hook into tree
+ retCtx.SetParent(parentCtx)
+ if p.BuildParseTrees && parentCtx != nil {
+ // add return ctx into invoking rule's tree
+ parentCtx.AddChild(retCtx)
+ }
+}
+
+func (p *BaseParser) GetInvokingContext(ruleIndex int) ParserRuleContext {
+ ctx := p.ctx
+ for ctx != nil {
+ if ctx.GetRuleIndex() == ruleIndex {
+ return ctx
+ }
+ ctx = ctx.GetParent().(ParserRuleContext)
+ }
+ return nil
+}
+
+func (p *BaseParser) Precpred(localctx RuleContext, precedence int) bool {
+ return precedence >= p.precedenceStack[len(p.precedenceStack)-1]
+}
+
+func (p *BaseParser) inContext(context ParserRuleContext) bool {
+ // TODO: useful in parser?
+ return false
+}
+
+//
+// Checks whether or not {@code symbol} can follow the current state in the
+// ATN. The behavior of p.method is equivalent to the following, but is
+// implemented such that the complete context-sensitive follow set does not
+// need to be explicitly constructed.
+//
+// +// return getExpectedTokens().contains(symbol) +//+// +// @param symbol the symbol type to check +// @return {@code true} if {@code symbol} can follow the current state in +// the ATN, otherwise {@code false}. + +func (p *BaseParser) IsExpectedToken(symbol int) bool { + atn := p.Interpreter.atn + ctx := p.ctx + s := atn.states[p.state] + following := atn.NextTokens(s, nil) + if following.contains(symbol) { + return true + } + if !following.contains(TokenEpsilon) { + return false + } + for ctx != nil && ctx.GetInvokingState() >= 0 && following.contains(TokenEpsilon) { + invokingState := atn.states[ctx.GetInvokingState()] + rt := invokingState.GetTransitions()[0] + following = atn.NextTokens(rt.(*RuleTransition).followState, nil) + if following.contains(symbol) { + return true + } + ctx = ctx.GetParent().(ParserRuleContext) + } + if following.contains(TokenEpsilon) && symbol == TokenEOF { + return true + } + + return false +} + +// Computes the set of input symbols which could follow the current parser +// state and context, as given by {@link //GetState} and {@link //GetContext}, +// respectively. +// +// @see ATN//getExpectedTokens(int, RuleContext) +func (p *BaseParser) GetExpectedTokens() *IntervalSet { + return p.Interpreter.atn.getExpectedTokens(p.state, p.ctx) +} + +func (p *BaseParser) GetExpectedTokensWithinCurrentRule() *IntervalSet { + atn := p.Interpreter.atn + s := atn.states[p.state] + return atn.NextTokens(s, nil) +} + +// Get a rule's index (i.e., {@code RULE_ruleName} field) or -1 if not found.// +func (p *BaseParser) GetRuleIndex(ruleName string) int { + var ruleIndex, ok = p.GetRuleIndexMap()[ruleName] + if ok { + return ruleIndex + } + + return -1 +} + +// Return List<String> of the rule names in your parser instance +// leading up to a call to the current rule. You could override if +// you want more details such as the file/line info of where +// in the ATN a rule is invoked. +// +// this very useful for error messages. + +func (p *BaseParser) GetRuleInvocationStack(c ParserRuleContext) []string { + if c == nil { + c = p.ctx + } + stack := make([]string, 0) + for c != nil { + // compute what follows who invoked us + ruleIndex := c.GetRuleIndex() + if ruleIndex < 0 { + stack = append(stack, "n/a") + } else { + stack = append(stack, p.GetRuleNames()[ruleIndex]) + } + + vp := c.GetParent() + + if vp == nil { + break + } + + c = vp.(ParserRuleContext) + } + return stack +} + +// For debugging and other purposes.// +func (p *BaseParser) GetDFAStrings() string { + return fmt.Sprint(p.Interpreter.decisionToDFA) +} + +// For debugging and other purposes.// +func (p *BaseParser) DumpDFA() { + seenOne := false + for _, dfa := range p.Interpreter.decisionToDFA { + if dfa.states.Len() > 0 { + if seenOne { + fmt.Println() + } + fmt.Println("Decision " + strconv.Itoa(dfa.decision) + ":") + fmt.Print(dfa.String(p.LiteralNames, p.SymbolicNames)) + seenOne = true + } + } +} + +func (p *BaseParser) GetSourceName() string { + return p.GrammarFileName +} + +// During a parse is sometimes useful to listen in on the rule entry and exit +// events as well as token Matches. p.is for quick and dirty debugging. +func (p *BaseParser) SetTrace(trace *TraceListener) { + if trace == nil { + p.RemoveParseListener(p.tracer) + p.tracer = nil + } else { + if p.tracer != nil { + p.RemoveParseListener(p.tracer) + } + p.tracer = NewTraceListener(p) + p.AddParseListener(p.tracer) + } +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_atn_simulator.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_atn_simulator.go index 8bcc46a0d9..95a3bb000c 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_atn_simulator.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_atn_simulator.go @@ -1,1559 +1,1559 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "fmt" - "strconv" - "strings" -) - -var ( - ParserATNSimulatorDebug = false - ParserATNSimulatorTraceATNSim = false - ParserATNSimulatorDFADebug = false - ParserATNSimulatorRetryDebug = false - TurnOffLRLoopEntryBranchOpt = false -) - -type ParserATNSimulator struct { - *BaseATNSimulator - - parser Parser - predictionMode int - input TokenStream - startIndex int - dfa *DFA - mergeCache *DoubleDict - outerContext ParserRuleContext -} - -func NewParserATNSimulator(parser Parser, atn *ATN, decisionToDFA []*DFA, sharedContextCache *PredictionContextCache) *ParserATNSimulator { - - p := new(ParserATNSimulator) - - p.BaseATNSimulator = NewBaseATNSimulator(atn, sharedContextCache) - - p.parser = parser - p.decisionToDFA = decisionToDFA - // SLL, LL, or LL + exact ambig detection?// - p.predictionMode = PredictionModeLL - // LAME globals to avoid parameters!!!!! I need these down deep in predTransition - p.input = nil - p.startIndex = 0 - p.outerContext = nil - p.dfa = nil - // Each prediction operation uses a cache for merge of prediction contexts. - // Don't keep around as it wastes huge amounts of memory. DoubleKeyMap - // isn't Synchronized but we're ok since two threads shouldn't reuse same - // parser/atnsim object because it can only handle one input at a time. - // This maps graphs a and b to merged result c. (a,b)&rarrc. We can avoid - // the merge if we ever see a and b again. Note that (b,a)&rarrc should - // also be examined during cache lookup. - // - p.mergeCache = nil - - return p -} - -func (p *ParserATNSimulator) GetPredictionMode() int { - return p.predictionMode -} - -func (p *ParserATNSimulator) SetPredictionMode(v int) { - p.predictionMode = v -} - -func (p *ParserATNSimulator) reset() { -} - -func (p *ParserATNSimulator) AdaptivePredict(input TokenStream, decision int, outerContext ParserRuleContext) int { - if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { - fmt.Println("adaptivePredict decision " + strconv.Itoa(decision) + - " exec LA(1)==" + p.getLookaheadName(input) + - " line " + strconv.Itoa(input.LT(1).GetLine()) + ":" + - strconv.Itoa(input.LT(1).GetColumn())) - } - - p.input = input - p.startIndex = input.Index() - p.outerContext = outerContext - - dfa := p.decisionToDFA[decision] - p.dfa = dfa - m := input.Mark() - index := input.Index() - - defer func() { - p.dfa = nil - p.mergeCache = nil // wack cache after each prediction - input.Seek(index) - input.Release(m) - }() - - // Now we are certain to have a specific decision's DFA - // But, do we still need an initial state? - var s0 *DFAState - p.atn.stateMu.RLock() - if dfa.getPrecedenceDfa() { - p.atn.edgeMu.RLock() - // the start state for a precedence DFA depends on the current - // parser precedence, and is provided by a DFA method. - s0 = dfa.getPrecedenceStartState(p.parser.GetPrecedence()) - p.atn.edgeMu.RUnlock() - } else { - // the start state for a "regular" DFA is just s0 - s0 = dfa.getS0() - } - p.atn.stateMu.RUnlock() - - if s0 == nil { - if outerContext == nil { - outerContext = ParserRuleContextEmpty - } - if ParserATNSimulatorDebug { - fmt.Println("predictATN decision " + strconv.Itoa(dfa.decision) + - " exec LA(1)==" + p.getLookaheadName(input) + - ", outerContext=" + outerContext.String(p.parser.GetRuleNames(), nil)) - } - fullCtx := false - s0Closure := p.computeStartState(dfa.atnStartState, ParserRuleContextEmpty, fullCtx) - - p.atn.stateMu.Lock() - if dfa.getPrecedenceDfa() { - // If p is a precedence DFA, we use applyPrecedenceFilter - // to convert the computed start state to a precedence start - // state. We then use DFA.setPrecedenceStartState to set the - // appropriate start state for the precedence level rather - // than simply setting DFA.s0. - // - dfa.s0.configs = s0Closure - s0Closure = p.applyPrecedenceFilter(s0Closure) - s0 = p.addDFAState(dfa, NewDFAState(-1, s0Closure)) - p.atn.edgeMu.Lock() - dfa.setPrecedenceStartState(p.parser.GetPrecedence(), s0) - p.atn.edgeMu.Unlock() - } else { - s0 = p.addDFAState(dfa, NewDFAState(-1, s0Closure)) - dfa.setS0(s0) - } - p.atn.stateMu.Unlock() - } - - alt := p.execATN(dfa, s0, input, index, outerContext) - if ParserATNSimulatorDebug { - fmt.Println("DFA after predictATN: " + dfa.String(p.parser.GetLiteralNames(), nil)) - } - return alt - -} - -// Performs ATN simulation to compute a predicted alternative based -// upon the remaining input, but also updates the DFA cache to avoid -// having to traverse the ATN again for the same input sequence. - -// There are some key conditions we're looking for after computing a new -// set of ATN configs (proposed DFA state): -// if the set is empty, there is no viable alternative for current symbol -// does the state uniquely predict an alternative? -// does the state have a conflict that would prevent us from -// putting it on the work list? - -// We also have some key operations to do: -// add an edge from previous DFA state to potentially NewDFA state, D, -// upon current symbol but only if adding to work list, which means in all -// cases except no viable alternative (and possibly non-greedy decisions?) -// collecting predicates and adding semantic context to DFA accept states -// adding rule context to context-sensitive DFA accept states -// consuming an input symbol -// Reporting a conflict -// Reporting an ambiguity -// Reporting a context sensitivity -// Reporting insufficient predicates - -// cover these cases: -// -// dead end -// single alt -// single alt + preds -// conflict -// conflict + preds -func (p *ParserATNSimulator) execATN(dfa *DFA, s0 *DFAState, input TokenStream, startIndex int, outerContext ParserRuleContext) int { - - if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { - fmt.Println("execATN decision " + strconv.Itoa(dfa.decision) + - ", DFA state " + s0.String() + - ", LA(1)==" + p.getLookaheadName(input) + - " line " + strconv.Itoa(input.LT(1).GetLine()) + ":" + strconv.Itoa(input.LT(1).GetColumn())) - } - - previousD := s0 - - if ParserATNSimulatorDebug { - fmt.Println("s0 = " + s0.String()) - } - t := input.LA(1) - for { // for more work - D := p.getExistingTargetState(previousD, t) - if D == nil { - D = p.computeTargetState(dfa, previousD, t) - } - if D == ATNSimulatorError { - // if any configs in previous dipped into outer context, that - // means that input up to t actually finished entry rule - // at least for SLL decision. Full LL doesn't dip into outer - // so don't need special case. - // We will get an error no matter what so delay until after - // decision better error message. Also, no reachable target - // ATN states in SLL implies LL will also get nowhere. - // If conflict in states that dip out, choose min since we - // will get error no matter what. - e := p.noViableAlt(input, outerContext, previousD.configs, startIndex) - input.Seek(startIndex) - alt := p.getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(previousD.configs, outerContext) - if alt != ATNInvalidAltNumber { - return alt - } - - panic(e) - } - if D.requiresFullContext && p.predictionMode != PredictionModeSLL { - // IF PREDS, MIGHT RESOLVE TO SINGLE ALT => SLL (or syntax error) - conflictingAlts := D.configs.GetConflictingAlts() - if D.predicates != nil { - if ParserATNSimulatorDebug { - fmt.Println("DFA state has preds in DFA sim LL failover") - } - conflictIndex := input.Index() - if conflictIndex != startIndex { - input.Seek(startIndex) - } - conflictingAlts = p.evalSemanticContext(D.predicates, outerContext, true) - if conflictingAlts.length() == 1 { - if ParserATNSimulatorDebug { - fmt.Println("Full LL avoided") - } - return conflictingAlts.minValue() - } - if conflictIndex != startIndex { - // restore the index so Reporting the fallback to full - // context occurs with the index at the correct spot - input.Seek(conflictIndex) - } - } - if ParserATNSimulatorDFADebug { - fmt.Println("ctx sensitive state " + outerContext.String(nil, nil) + " in " + D.String()) - } - fullCtx := true - s0Closure := p.computeStartState(dfa.atnStartState, outerContext, fullCtx) - p.ReportAttemptingFullContext(dfa, conflictingAlts, D.configs, startIndex, input.Index()) - alt := p.execATNWithFullContext(dfa, D, s0Closure, input, startIndex, outerContext) - return alt - } - if D.isAcceptState { - if D.predicates == nil { - return D.prediction - } - stopIndex := input.Index() - input.Seek(startIndex) - alts := p.evalSemanticContext(D.predicates, outerContext, true) - - switch alts.length() { - case 0: - panic(p.noViableAlt(input, outerContext, D.configs, startIndex)) - case 1: - return alts.minValue() - default: - // Report ambiguity after predicate evaluation to make sure the correct set of ambig alts is Reported. - p.ReportAmbiguity(dfa, D, startIndex, stopIndex, false, alts, D.configs) - return alts.minValue() - } - } - previousD = D - - if t != TokenEOF { - input.Consume() - t = input.LA(1) - } - } -} - -// Get an existing target state for an edge in the DFA. If the target state -// for the edge has not yet been computed or is otherwise not available, -// p method returns {@code nil}. -// -// @param previousD The current DFA state -// @param t The next input symbol -// @return The existing target DFA state for the given input symbol -// {@code t}, or {@code nil} if the target state for p edge is not -// already cached - -func (p *ParserATNSimulator) getExistingTargetState(previousD *DFAState, t int) *DFAState { - if t+1 < 0 { - return nil - } - - p.atn.edgeMu.RLock() - defer p.atn.edgeMu.RUnlock() - edges := previousD.getEdges() - if edges == nil || t+1 >= len(edges) { - return nil - } - return previousD.getIthEdge(t + 1) -} - -// Compute a target state for an edge in the DFA, and attempt to add the -// computed state and corresponding edge to the DFA. -// -// @param dfa The DFA -// @param previousD The current DFA state -// @param t The next input symbol -// -// @return The computed target DFA state for the given input symbol -// {@code t}. If {@code t} does not lead to a valid DFA state, p method -// returns {@link //ERROR}. - -func (p *ParserATNSimulator) computeTargetState(dfa *DFA, previousD *DFAState, t int) *DFAState { - reach := p.computeReachSet(previousD.configs, t, false) - - if reach == nil { - p.addDFAEdge(dfa, previousD, t, ATNSimulatorError) - return ATNSimulatorError - } - // create Newtarget state we'll add to DFA after it's complete - D := NewDFAState(-1, reach) - - predictedAlt := p.getUniqueAlt(reach) - - if ParserATNSimulatorDebug { - altSubSets := PredictionModegetConflictingAltSubsets(reach) - fmt.Println("SLL altSubSets=" + fmt.Sprint(altSubSets) + - ", previous=" + previousD.configs.String() + - ", configs=" + reach.String() + - ", predict=" + strconv.Itoa(predictedAlt) + - ", allSubsetsConflict=" + - fmt.Sprint(PredictionModeallSubsetsConflict(altSubSets)) + - ", conflictingAlts=" + p.getConflictingAlts(reach).String()) - } - if predictedAlt != ATNInvalidAltNumber { - // NO CONFLICT, UNIQUELY PREDICTED ALT - D.isAcceptState = true - D.configs.SetUniqueAlt(predictedAlt) - D.setPrediction(predictedAlt) - } else if PredictionModehasSLLConflictTerminatingPrediction(p.predictionMode, reach) { - // MORE THAN ONE VIABLE ALTERNATIVE - D.configs.SetConflictingAlts(p.getConflictingAlts(reach)) - D.requiresFullContext = true - // in SLL-only mode, we will stop at p state and return the minimum alt - D.isAcceptState = true - D.setPrediction(D.configs.GetConflictingAlts().minValue()) - } - if D.isAcceptState && D.configs.HasSemanticContext() { - p.predicateDFAState(D, p.atn.getDecisionState(dfa.decision)) - if D.predicates != nil { - D.setPrediction(ATNInvalidAltNumber) - } - } - // all adds to dfa are done after we've created full D state - D = p.addDFAEdge(dfa, previousD, t, D) - return D -} - -func (p *ParserATNSimulator) predicateDFAState(dfaState *DFAState, decisionState DecisionState) { - // We need to test all predicates, even in DFA states that - // uniquely predict alternative. - nalts := len(decisionState.GetTransitions()) - // Update DFA so reach becomes accept state with (predicate,alt) - // pairs if preds found for conflicting alts - altsToCollectPredsFrom := p.getConflictingAltsOrUniqueAlt(dfaState.configs) - altToPred := p.getPredsForAmbigAlts(altsToCollectPredsFrom, dfaState.configs, nalts) - if altToPred != nil { - dfaState.predicates = p.getPredicatePredictions(altsToCollectPredsFrom, altToPred) - dfaState.setPrediction(ATNInvalidAltNumber) // make sure we use preds - } else { - // There are preds in configs but they might go away - // when OR'd together like {p}? || NONE == NONE. If neither - // alt has preds, resolve to min alt - dfaState.setPrediction(altsToCollectPredsFrom.minValue()) - } -} - -// comes back with reach.uniqueAlt set to a valid alt -func (p *ParserATNSimulator) execATNWithFullContext(dfa *DFA, D *DFAState, s0 ATNConfigSet, input TokenStream, startIndex int, outerContext ParserRuleContext) int { - - if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { - fmt.Println("execATNWithFullContext " + s0.String()) - } - - fullCtx := true - foundExactAmbig := false - var reach ATNConfigSet - previous := s0 - input.Seek(startIndex) - t := input.LA(1) - predictedAlt := -1 - - for { // for more work - reach = p.computeReachSet(previous, t, fullCtx) - if reach == nil { - // if any configs in previous dipped into outer context, that - // means that input up to t actually finished entry rule - // at least for LL decision. Full LL doesn't dip into outer - // so don't need special case. - // We will get an error no matter what so delay until after - // decision better error message. Also, no reachable target - // ATN states in SLL implies LL will also get nowhere. - // If conflict in states that dip out, choose min since we - // will get error no matter what. - e := p.noViableAlt(input, outerContext, previous, startIndex) - input.Seek(startIndex) - alt := p.getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(previous, outerContext) - if alt != ATNInvalidAltNumber { - return alt - } - - panic(e) - } - altSubSets := PredictionModegetConflictingAltSubsets(reach) - if ParserATNSimulatorDebug { - fmt.Println("LL altSubSets=" + fmt.Sprint(altSubSets) + ", predict=" + - strconv.Itoa(PredictionModegetUniqueAlt(altSubSets)) + ", resolvesToJustOneViableAlt=" + - fmt.Sprint(PredictionModeresolvesToJustOneViableAlt(altSubSets))) - } - reach.SetUniqueAlt(p.getUniqueAlt(reach)) - // unique prediction? - if reach.GetUniqueAlt() != ATNInvalidAltNumber { - predictedAlt = reach.GetUniqueAlt() - break - } - if p.predictionMode != PredictionModeLLExactAmbigDetection { - predictedAlt = PredictionModeresolvesToJustOneViableAlt(altSubSets) - if predictedAlt != ATNInvalidAltNumber { - break - } - } else { - // In exact ambiguity mode, we never try to terminate early. - // Just keeps scarfing until we know what the conflict is - if PredictionModeallSubsetsConflict(altSubSets) && PredictionModeallSubsetsEqual(altSubSets) { - foundExactAmbig = true - predictedAlt = PredictionModegetSingleViableAlt(altSubSets) - break - } - // else there are multiple non-conflicting subsets or - // we're not sure what the ambiguity is yet. - // So, keep going. - } - previous = reach - if t != TokenEOF { - input.Consume() - t = input.LA(1) - } - } - // If the configuration set uniquely predicts an alternative, - // without conflict, then we know that it's a full LL decision - // not SLL. - if reach.GetUniqueAlt() != ATNInvalidAltNumber { - p.ReportContextSensitivity(dfa, predictedAlt, reach, startIndex, input.Index()) - return predictedAlt - } - // We do not check predicates here because we have checked them - // on-the-fly when doing full context prediction. - - // - // In non-exact ambiguity detection mode, we might actually be able to - // detect an exact ambiguity, but I'm not going to spend the cycles - // needed to check. We only emit ambiguity warnings in exact ambiguity - // mode. - // - // For example, we might know that we have conflicting configurations. - // But, that does not mean that there is no way forward without a - // conflict. It's possible to have nonconflicting alt subsets as in: - - // altSubSets=[{1, 2}, {1, 2}, {1}, {1, 2}] - - // from - // - // [(17,1,[5 $]), (13,1,[5 10 $]), (21,1,[5 10 $]), (11,1,[$]), - // (13,2,[5 10 $]), (21,2,[5 10 $]), (11,2,[$])] - // - // In p case, (17,1,[5 $]) indicates there is some next sequence that - // would resolve p without conflict to alternative 1. Any other viable - // next sequence, however, is associated with a conflict. We stop - // looking for input because no amount of further lookahead will alter - // the fact that we should predict alternative 1. We just can't say for - // sure that there is an ambiguity without looking further. - - p.ReportAmbiguity(dfa, D, startIndex, input.Index(), foundExactAmbig, reach.Alts(), reach) - - return predictedAlt -} - -func (p *ParserATNSimulator) computeReachSet(closure ATNConfigSet, t int, fullCtx bool) ATNConfigSet { - if p.mergeCache == nil { - p.mergeCache = NewDoubleDict() - } - intermediate := NewBaseATNConfigSet(fullCtx) - - // Configurations already in a rule stop state indicate reaching the end - // of the decision rule (local context) or end of the start rule (full - // context). Once reached, these configurations are never updated by a - // closure operation, so they are handled separately for the performance - // advantage of having a smaller intermediate set when calling closure. - // - // For full-context reach operations, separate handling is required to - // ensure that the alternative Matching the longest overall sequence is - // chosen when multiple such configurations can Match the input. - - var skippedStopStates []*BaseATNConfig - - // First figure out where we can reach on input t - for _, c := range closure.GetItems() { - if ParserATNSimulatorDebug { - fmt.Println("testing " + p.GetTokenName(t) + " at " + c.String()) - } - - if _, ok := c.GetState().(*RuleStopState); ok { - if fullCtx || t == TokenEOF { - skippedStopStates = append(skippedStopStates, c.(*BaseATNConfig)) - if ParserATNSimulatorDebug { - fmt.Println("added " + c.String() + " to SkippedStopStates") - } - } - continue - } - - for _, trans := range c.GetState().GetTransitions() { - target := p.getReachableTarget(trans, t) - if target != nil { - cfg := NewBaseATNConfig4(c, target) - intermediate.Add(cfg, p.mergeCache) - if ParserATNSimulatorDebug { - fmt.Println("added " + cfg.String() + " to intermediate") - } - } - } - } - - // Now figure out where the reach operation can take us... - var reach ATNConfigSet - - // This block optimizes the reach operation for intermediate sets which - // trivially indicate a termination state for the overall - // AdaptivePredict operation. - // - // The conditions assume that intermediate - // contains all configurations relevant to the reach set, but p - // condition is not true when one or more configurations have been - // withheld in SkippedStopStates, or when the current symbol is EOF. - // - if skippedStopStates == nil && t != TokenEOF { - if len(intermediate.configs) == 1 { - // Don't pursue the closure if there is just one state. - // It can only have one alternative just add to result - // Also don't pursue the closure if there is unique alternative - // among the configurations. - reach = intermediate - } else if p.getUniqueAlt(intermediate) != ATNInvalidAltNumber { - // Also don't pursue the closure if there is unique alternative - // among the configurations. - reach = intermediate - } - } - // If the reach set could not be trivially determined, perform a closure - // operation on the intermediate set to compute its initial value. - // - if reach == nil { - reach = NewBaseATNConfigSet(fullCtx) - closureBusy := NewJStore[ATNConfig, Comparator[ATNConfig]](aConfEqInst) - treatEOFAsEpsilon := t == TokenEOF - amount := len(intermediate.configs) - for k := 0; k < amount; k++ { - p.closure(intermediate.configs[k], reach, closureBusy, false, fullCtx, treatEOFAsEpsilon) - } - } - if t == TokenEOF { - // After consuming EOF no additional input is possible, so we are - // only interested in configurations which reached the end of the - // decision rule (local context) or end of the start rule (full - // context). Update reach to contain only these configurations. This - // handles both explicit EOF transitions in the grammar and implicit - // EOF transitions following the end of the decision or start rule. - // - // When reach==intermediate, no closure operation was performed. In - // p case, removeAllConfigsNotInRuleStopState needs to check for - // reachable rule stop states as well as configurations already in - // a rule stop state. - // - // This is handled before the configurations in SkippedStopStates, - // because any configurations potentially added from that list are - // already guaranteed to meet p condition whether or not it's - // required. - // - reach = p.removeAllConfigsNotInRuleStopState(reach, reach == intermediate) - } - // If SkippedStopStates!=nil, then it contains at least one - // configuration. For full-context reach operations, these - // configurations reached the end of the start rule, in which case we - // only add them back to reach if no configuration during the current - // closure operation reached such a state. This ensures AdaptivePredict - // chooses an alternative Matching the longest overall sequence when - // multiple alternatives are viable. - // - if skippedStopStates != nil && ((!fullCtx) || (!PredictionModehasConfigInRuleStopState(reach))) { - for l := 0; l < len(skippedStopStates); l++ { - reach.Add(skippedStopStates[l], p.mergeCache) - } - } - - if ParserATNSimulatorTraceATNSim { - fmt.Println("computeReachSet " + closure.String() + " -> " + reach.String()) - } - - if len(reach.GetItems()) == 0 { - return nil - } - - return reach -} - -// Return a configuration set containing only the configurations from -// {@code configs} which are in a {@link RuleStopState}. If all -// configurations in {@code configs} are already in a rule stop state, p -// method simply returns {@code configs}. -// -//
When {@code lookToEndOfRule} is true, p method uses -// {@link ATN//NextTokens} for each configuration in {@code configs} which is -// not already in a rule stop state to see if a rule stop state is reachable -// from the configuration via epsilon-only transitions.
-// -// @param configs the configuration set to update -// @param lookToEndOfRule when true, p method checks for rule stop states -// reachable by epsilon-only transitions from each configuration in -// {@code configs}. -// -// @return {@code configs} if all configurations in {@code configs} are in a -// rule stop state, otherwise return a Newconfiguration set containing only -// the configurations from {@code configs} which are in a rule stop state -func (p *ParserATNSimulator) removeAllConfigsNotInRuleStopState(configs ATNConfigSet, lookToEndOfRule bool) ATNConfigSet { - if PredictionModeallConfigsInRuleStopStates(configs) { - return configs - } - result := NewBaseATNConfigSet(configs.FullContext()) - for _, config := range configs.GetItems() { - if _, ok := config.GetState().(*RuleStopState); ok { - result.Add(config, p.mergeCache) - continue - } - if lookToEndOfRule && config.GetState().GetEpsilonOnlyTransitions() { - NextTokens := p.atn.NextTokens(config.GetState(), nil) - if NextTokens.contains(TokenEpsilon) { - endOfRuleState := p.atn.ruleToStopState[config.GetState().GetRuleIndex()] - result.Add(NewBaseATNConfig4(config, endOfRuleState), p.mergeCache) - } - } - } - return result -} - -func (p *ParserATNSimulator) computeStartState(a ATNState, ctx RuleContext, fullCtx bool) ATNConfigSet { - // always at least the implicit call to start rule - initialContext := predictionContextFromRuleContext(p.atn, ctx) - configs := NewBaseATNConfigSet(fullCtx) - if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { - fmt.Println("computeStartState from ATN state " + a.String() + - " initialContext=" + initialContext.String()) - } - - for i := 0; i < len(a.GetTransitions()); i++ { - target := a.GetTransitions()[i].getTarget() - c := NewBaseATNConfig6(target, i+1, initialContext) - closureBusy := NewJStore[ATNConfig, Comparator[ATNConfig]](atnConfCompInst) - p.closure(c, configs, closureBusy, true, fullCtx, false) - } - return configs -} - -// This method transforms the start state computed by -// {@link //computeStartState} to the special start state used by a -// precedence DFA for a particular precedence value. The transformation -// process applies the following changes to the start state's configuration -// set. -// -//-
-//
- Evaluate the precedence predicates for each configuration using -// {@link SemanticContext//evalPrecedence}. -//
- Remove all configurations which predict an alternative greater than
-// 1, for which another configuration that predicts alternative 1 is in the
-// same ATN state with the same prediction context. This transformation is
-// valid for the following reasons:
-//
-
-//
- The closure block cannot contain any epsilon transitions which bypass -// the body of the closure, so all states reachable via alternative 1 are -// part of the precedence alternatives of the transformed left-recursive -// rule. -//
- The "primary" portion of a left recursive rule cannot contain an -// epsilon transition, so the only way an alternative other than 1 can exist -// in a state that is also reachable via alternative 1 is by nesting calls -// to the left-recursive rule, with the outer calls not being at the -// preferred precedence level. -//
-//
-// The prediction context must be considered by p filter to address -// situations like the following. -//
-//
-//
-// grammar TA
-// prog: statement* EOF
-// statement: letterA | statement letterA 'b'
-// letterA: 'a'
-//
-//
-// -// If the above grammar, the ATN state immediately before the token -// reference {@code 'a'} in {@code letterA} is reachable from the left edge -// of both the primary and closure blocks of the left-recursive rule -// {@code statement}. The prediction context associated with each of these -// configurations distinguishes between them, and prevents the alternative -// which stepped out to {@code prog} (and then back in to {@code statement} -// from being eliminated by the filter. -//
-// -// @param configs The configuration set computed by -// {@link //computeStartState} as the start state for the DFA. -// @return The transformed configuration set representing the start state -// for a precedence DFA at a particular precedence level (determined by -// calling {@link Parser//getPrecedence}). -func (p *ParserATNSimulator) applyPrecedenceFilter(configs ATNConfigSet) ATNConfigSet { - - statesFromAlt1 := make(map[int]PredictionContext) - configSet := NewBaseATNConfigSet(configs.FullContext()) - - for _, config := range configs.GetItems() { - // handle alt 1 first - if config.GetAlt() != 1 { - continue - } - updatedContext := config.GetSemanticContext().evalPrecedence(p.parser, p.outerContext) - if updatedContext == nil { - // the configuration was eliminated - continue - } - statesFromAlt1[config.GetState().GetStateNumber()] = config.GetContext() - if updatedContext != config.GetSemanticContext() { - configSet.Add(NewBaseATNConfig2(config, updatedContext), p.mergeCache) - } else { - configSet.Add(config, p.mergeCache) - } - } - for _, config := range configs.GetItems() { - - if config.GetAlt() == 1 { - // already handled - continue - } - // In the future, p elimination step could be updated to also - // filter the prediction context for alternatives predicting alt>1 - // (basically a graph subtraction algorithm). - if !config.getPrecedenceFilterSuppressed() { - context := statesFromAlt1[config.GetState().GetStateNumber()] - if context != nil && context.Equals(config.GetContext()) { - // eliminated - continue - } - } - configSet.Add(config, p.mergeCache) - } - return configSet -} - -func (p *ParserATNSimulator) getReachableTarget(trans Transition, ttype int) ATNState { - if trans.Matches(ttype, 0, p.atn.maxTokenType) { - return trans.getTarget() - } - - return nil -} - -func (p *ParserATNSimulator) getPredsForAmbigAlts(ambigAlts *BitSet, configs ATNConfigSet, nalts int) []SemanticContext { - - altToPred := make([]SemanticContext, nalts+1) - for _, c := range configs.GetItems() { - if ambigAlts.contains(c.GetAlt()) { - altToPred[c.GetAlt()] = SemanticContextorContext(altToPred[c.GetAlt()], c.GetSemanticContext()) - } - } - nPredAlts := 0 - for i := 1; i <= nalts; i++ { - pred := altToPred[i] - if pred == nil { - altToPred[i] = SemanticContextNone - } else if pred != SemanticContextNone { - nPredAlts++ - } - } - // nonambig alts are nil in altToPred - if nPredAlts == 0 { - altToPred = nil - } - if ParserATNSimulatorDebug { - fmt.Println("getPredsForAmbigAlts result " + fmt.Sprint(altToPred)) - } - return altToPred -} - -func (p *ParserATNSimulator) getPredicatePredictions(ambigAlts *BitSet, altToPred []SemanticContext) []*PredPrediction { - pairs := make([]*PredPrediction, 0) - containsPredicate := false - for i := 1; i < len(altToPred); i++ { - pred := altToPred[i] - // unpredicated is indicated by SemanticContextNONE - if ambigAlts != nil && ambigAlts.contains(i) { - pairs = append(pairs, NewPredPrediction(pred, i)) - } - if pred != SemanticContextNone { - containsPredicate = true - } - } - if !containsPredicate { - return nil - } - return pairs -} - -// This method is used to improve the localization of error messages by -// choosing an alternative rather than panicing a -// {@link NoViableAltException} in particular prediction scenarios where the -// {@link //ERROR} state was reached during ATN simulation. -// -//-// The default implementation of p method uses the following -// algorithm to identify an ATN configuration which successfully parsed the -// decision entry rule. Choosing such an alternative ensures that the -// {@link ParserRuleContext} returned by the calling rule will be complete -// and valid, and the syntax error will be Reported later at a more -// localized location.
-// -//-
-//
- If a syntactically valid path or paths reach the end of the decision rule and -// they are semantically valid if predicated, return the min associated alt. -//
- Else, if a semantically invalid but syntactically valid path exist -// or paths exist, return the minimum associated alt. -// -//
- Otherwise, return {@link ATN//INVALID_ALT_NUMBER}. -//
-// In some scenarios, the algorithm described above could predict an -// alternative which will result in a {@link FailedPredicateException} in -// the parser. Specifically, p could occur if the only configuration -// capable of successfully parsing to the end of the decision rule is -// blocked by a semantic predicate. By choosing p alternative within -// {@link //AdaptivePredict} instead of panicing a -// {@link NoViableAltException}, the resulting -// {@link FailedPredicateException} in the parser will identify the specific -// predicate which is preventing the parser from successfully parsing the -// decision rule, which helps developers identify and correct logic errors -// in semantic predicates. -//
-// -// @param configs The ATN configurations which were valid immediately before -// the {@link //ERROR} state was reached -// @param outerContext The is the \gamma_0 initial parser context from the paper -// or the parser stack at the instant before prediction commences. -// -// @return The value to return from {@link //AdaptivePredict}, or -// {@link ATN//INVALID_ALT_NUMBER} if a suitable alternative was not -// identified and {@link //AdaptivePredict} should Report an error instead. -func (p *ParserATNSimulator) getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(configs ATNConfigSet, outerContext ParserRuleContext) int { - cfgs := p.splitAccordingToSemanticValidity(configs, outerContext) - semValidConfigs := cfgs[0] - semInvalidConfigs := cfgs[1] - alt := p.GetAltThatFinishedDecisionEntryRule(semValidConfigs) - if alt != ATNInvalidAltNumber { // semantically/syntactically viable path exists - return alt - } - // Is there a syntactically valid path with a failed pred? - if len(semInvalidConfigs.GetItems()) > 0 { - alt = p.GetAltThatFinishedDecisionEntryRule(semInvalidConfigs) - if alt != ATNInvalidAltNumber { // syntactically viable path exists - return alt - } - } - return ATNInvalidAltNumber -} - -func (p *ParserATNSimulator) GetAltThatFinishedDecisionEntryRule(configs ATNConfigSet) int { - alts := NewIntervalSet() - - for _, c := range configs.GetItems() { - _, ok := c.GetState().(*RuleStopState) - - if c.GetReachesIntoOuterContext() > 0 || (ok && c.GetContext().hasEmptyPath()) { - alts.addOne(c.GetAlt()) - } - } - if alts.length() == 0 { - return ATNInvalidAltNumber - } - - return alts.first() -} - -// Walk the list of configurations and split them according to -// those that have preds evaluating to true/false. If no pred, assume -// true pred and include in succeeded set. Returns Pair of sets. -// -// Create a NewSet so as not to alter the incoming parameter. -// -// Assumption: the input stream has been restored to the starting point -// prediction, which is where predicates need to evaluate. - -type ATNConfigSetPair struct { - item0, item1 ATNConfigSet -} - -func (p *ParserATNSimulator) splitAccordingToSemanticValidity(configs ATNConfigSet, outerContext ParserRuleContext) []ATNConfigSet { - succeeded := NewBaseATNConfigSet(configs.FullContext()) - failed := NewBaseATNConfigSet(configs.FullContext()) - - for _, c := range configs.GetItems() { - if c.GetSemanticContext() != SemanticContextNone { - predicateEvaluationResult := c.GetSemanticContext().evaluate(p.parser, outerContext) - if predicateEvaluationResult { - succeeded.Add(c, nil) - } else { - failed.Add(c, nil) - } - } else { - succeeded.Add(c, nil) - } - } - return []ATNConfigSet{succeeded, failed} -} - -// Look through a list of predicate/alt pairs, returning alts for the -// -// pairs that win. A {@code NONE} predicate indicates an alt containing an -// unpredicated config which behaves as "always true." If !complete -// then we stop at the first predicate that evaluates to true. This -// includes pairs with nil predicates. -func (p *ParserATNSimulator) evalSemanticContext(predPredictions []*PredPrediction, outerContext ParserRuleContext, complete bool) *BitSet { - predictions := NewBitSet() - for i := 0; i < len(predPredictions); i++ { - pair := predPredictions[i] - if pair.pred == SemanticContextNone { - predictions.add(pair.alt) - if !complete { - break - } - continue - } - - predicateEvaluationResult := pair.pred.evaluate(p.parser, outerContext) - if ParserATNSimulatorDebug || ParserATNSimulatorDFADebug { - fmt.Println("eval pred " + pair.String() + "=" + fmt.Sprint(predicateEvaluationResult)) - } - if predicateEvaluationResult { - if ParserATNSimulatorDebug || ParserATNSimulatorDFADebug { - fmt.Println("PREDICT " + fmt.Sprint(pair.alt)) - } - predictions.add(pair.alt) - if !complete { - break - } - } - } - return predictions -} - -func (p *ParserATNSimulator) closure(config ATNConfig, configs ATNConfigSet, closureBusy *JStore[ATNConfig, Comparator[ATNConfig]], collectPredicates, fullCtx, treatEOFAsEpsilon bool) { - initialDepth := 0 - p.closureCheckingStopState(config, configs, closureBusy, collectPredicates, - fullCtx, initialDepth, treatEOFAsEpsilon) -} - -func (p *ParserATNSimulator) closureCheckingStopState(config ATNConfig, configs ATNConfigSet, closureBusy *JStore[ATNConfig, Comparator[ATNConfig]], collectPredicates, fullCtx bool, depth int, treatEOFAsEpsilon bool) { - if ParserATNSimulatorTraceATNSim { - fmt.Println("closure(" + config.String() + ")") - //fmt.Println("configs(" + configs.String() + ")") - if config.GetReachesIntoOuterContext() > 50 { - panic("problem") - } - } - - if _, ok := config.GetState().(*RuleStopState); ok { - // We hit rule end. If we have context info, use it - // run thru all possible stack tops in ctx - if !config.GetContext().isEmpty() { - for i := 0; i < config.GetContext().length(); i++ { - if config.GetContext().getReturnState(i) == BasePredictionContextEmptyReturnState { - if fullCtx { - configs.Add(NewBaseATNConfig1(config, config.GetState(), BasePredictionContextEMPTY), p.mergeCache) - continue - } else { - // we have no context info, just chase follow links (if greedy) - if ParserATNSimulatorDebug { - fmt.Println("FALLING off rule " + p.getRuleName(config.GetState().GetRuleIndex())) - } - p.closureWork(config, configs, closureBusy, collectPredicates, fullCtx, depth, treatEOFAsEpsilon) - } - continue - } - returnState := p.atn.states[config.GetContext().getReturnState(i)] - newContext := config.GetContext().GetParent(i) // "pop" return state - - c := NewBaseATNConfig5(returnState, config.GetAlt(), newContext, config.GetSemanticContext()) - // While we have context to pop back from, we may have - // gotten that context AFTER having falling off a rule. - // Make sure we track that we are now out of context. - c.SetReachesIntoOuterContext(config.GetReachesIntoOuterContext()) - p.closureCheckingStopState(c, configs, closureBusy, collectPredicates, fullCtx, depth-1, treatEOFAsEpsilon) - } - return - } else if fullCtx { - // reached end of start rule - configs.Add(config, p.mergeCache) - return - } else { - // else if we have no context info, just chase follow links (if greedy) - if ParserATNSimulatorDebug { - fmt.Println("FALLING off rule " + p.getRuleName(config.GetState().GetRuleIndex())) - } - } - } - p.closureWork(config, configs, closureBusy, collectPredicates, fullCtx, depth, treatEOFAsEpsilon) -} - -// Do the actual work of walking epsilon edges// -func (p *ParserATNSimulator) closureWork(config ATNConfig, configs ATNConfigSet, closureBusy *JStore[ATNConfig, Comparator[ATNConfig]], collectPredicates, fullCtx bool, depth int, treatEOFAsEpsilon bool) { - state := config.GetState() - // optimization - if !state.GetEpsilonOnlyTransitions() { - configs.Add(config, p.mergeCache) - // make sure to not return here, because EOF transitions can act as - // both epsilon transitions and non-epsilon transitions. - } - for i := 0; i < len(state.GetTransitions()); i++ { - if i == 0 && p.canDropLoopEntryEdgeInLeftRecursiveRule(config) { - continue - } - - t := state.GetTransitions()[i] - _, ok := t.(*ActionTransition) - continueCollecting := collectPredicates && !ok - c := p.getEpsilonTarget(config, t, continueCollecting, depth == 0, fullCtx, treatEOFAsEpsilon) - if ci, ok := c.(*BaseATNConfig); ok && ci != nil { - newDepth := depth - - if _, ok := config.GetState().(*RuleStopState); ok { - // target fell off end of rule mark resulting c as having dipped into outer context - // We can't get here if incoming config was rule stop and we had context - // track how far we dip into outer context. Might - // come in handy and we avoid evaluating context dependent - // preds if p is > 0. - - if p.dfa != nil && p.dfa.getPrecedenceDfa() { - if t.(*EpsilonTransition).outermostPrecedenceReturn == p.dfa.atnStartState.GetRuleIndex() { - c.setPrecedenceFilterSuppressed(true) - } - } - - c.SetReachesIntoOuterContext(c.GetReachesIntoOuterContext() + 1) - - _, present := closureBusy.Put(c) - if present { - // avoid infinite recursion for right-recursive rules - continue - } - - configs.SetDipsIntoOuterContext(true) // TODO: can remove? only care when we add to set per middle of p method - newDepth-- - if ParserATNSimulatorDebug { - fmt.Println("dips into outer ctx: " + c.String()) - } - } else { - - if !t.getIsEpsilon() { - _, present := closureBusy.Put(c) - if present { - // avoid infinite recursion for EOF* and EOF+ - continue - } - } - if _, ok := t.(*RuleTransition); ok { - // latch when newDepth goes negative - once we step out of the entry context we can't return - if newDepth >= 0 { - newDepth++ - } - } - } - p.closureCheckingStopState(c, configs, closureBusy, continueCollecting, fullCtx, newDepth, treatEOFAsEpsilon) - } - } -} - -func (p *ParserATNSimulator) canDropLoopEntryEdgeInLeftRecursiveRule(config ATNConfig) bool { - if TurnOffLRLoopEntryBranchOpt { - return false - } - - _p := config.GetState() - - // First check to see if we are in StarLoopEntryState generated during - // left-recursion elimination. For efficiency, also check if - // the context has an empty stack case. If so, it would mean - // global FOLLOW so we can't perform optimization - if _p.GetStateType() != ATNStateStarLoopEntry { - return false - } - startLoop, ok := _p.(*StarLoopEntryState) - if !ok { - return false - } - if !startLoop.precedenceRuleDecision || - config.GetContext().isEmpty() || - config.GetContext().hasEmptyPath() { - return false - } - - // Require all return states to return back to the same rule - // that p is in. - numCtxs := config.GetContext().length() - for i := 0; i < numCtxs; i++ { - returnState := p.atn.states[config.GetContext().getReturnState(i)] - if returnState.GetRuleIndex() != _p.GetRuleIndex() { - return false - } - } - x := _p.GetTransitions()[0].getTarget() - decisionStartState := x.(BlockStartState) - blockEndStateNum := decisionStartState.getEndState().stateNumber - blockEndState := p.atn.states[blockEndStateNum].(*BlockEndState) - - // Verify that the top of each stack context leads to loop entry/exit - // state through epsilon edges and w/o leaving rule. - - for i := 0; i < numCtxs; i++ { // for each stack context - returnStateNumber := config.GetContext().getReturnState(i) - returnState := p.atn.states[returnStateNumber] - - // all states must have single outgoing epsilon edge - if len(returnState.GetTransitions()) != 1 || !returnState.GetTransitions()[0].getIsEpsilon() { - return false - } - - // Look for prefix op case like 'not expr', (' type ')' expr - returnStateTarget := returnState.GetTransitions()[0].getTarget() - if returnState.GetStateType() == ATNStateBlockEnd && returnStateTarget == _p { - continue - } - - // Look for 'expr op expr' or case where expr's return state is block end - // of (...)* internal block; the block end points to loop back - // which points to p but we don't need to check that - if returnState == blockEndState { - continue - } - - // Look for ternary expr ? expr : expr. The return state points at block end, - // which points at loop entry state - if returnStateTarget == blockEndState { - continue - } - - // Look for complex prefix 'between expr and expr' case where 2nd expr's - // return state points at block end state of (...)* internal block - if returnStateTarget.GetStateType() == ATNStateBlockEnd && - len(returnStateTarget.GetTransitions()) == 1 && - returnStateTarget.GetTransitions()[0].getIsEpsilon() && - returnStateTarget.GetTransitions()[0].getTarget() == _p { - continue - } - - // anything else ain't conforming - return false - } - - return true -} - -func (p *ParserATNSimulator) getRuleName(index int) string { - if p.parser != nil && index >= 0 { - return p.parser.GetRuleNames()[index] - } - var sb strings.Builder - sb.Grow(32) - - sb.WriteString("If {@code to} is {@code nil}, p method returns {@code nil}. -// Otherwise, p method returns the {@link DFAState} returned by calling -// {@link //addDFAState} for the {@code to} state.
-// -// @param dfa The DFA -// @param from The source state for the edge -// @param t The input symbol -// @param to The target state for the edge -// -// @return If {@code to} is {@code nil}, p method returns {@code nil} -// otherwise p method returns the result of calling {@link //addDFAState} -// on {@code to} -func (p *ParserATNSimulator) addDFAEdge(dfa *DFA, from *DFAState, t int, to *DFAState) *DFAState { - if ParserATNSimulatorDebug { - fmt.Println("EDGE " + from.String() + " -> " + to.String() + " upon " + p.GetTokenName(t)) - } - if to == nil { - return nil - } - p.atn.stateMu.Lock() - to = p.addDFAState(dfa, to) // used existing if possible not incoming - p.atn.stateMu.Unlock() - if from == nil || t < -1 || t > p.atn.maxTokenType { - return to - } - p.atn.edgeMu.Lock() - if from.getEdges() == nil { - from.setEdges(make([]*DFAState, p.atn.maxTokenType+1+1)) - } - from.setIthEdge(t+1, to) // connect - p.atn.edgeMu.Unlock() - - if ParserATNSimulatorDebug { - var names []string - if p.parser != nil { - names = p.parser.GetLiteralNames() - } - - fmt.Println("DFA=\n" + dfa.String(names, nil)) - } - return to -} - -// Add state {@code D} to the DFA if it is not already present, and return -// the actual instance stored in the DFA. If a state equivalent to {@code D} -// is already in the DFA, the existing state is returned. Otherwise p -// method returns {@code D} after adding it to the DFA. -// -//If {@code D} is {@link //ERROR}, p method returns {@link //ERROR} and -// does not change the DFA.
-// -// @param dfa The dfa -// @param D The DFA state to add -// @return The state stored in the DFA. This will be either the existing -// state if {@code D} is already in the DFA, or {@code D} itself if the -// state was not already present. -func (p *ParserATNSimulator) addDFAState(dfa *DFA, d *DFAState) *DFAState { - if d == ATNSimulatorError { - return d - } - existing, present := dfa.states.Get(d) - if present { - if ParserATNSimulatorTraceATNSim { - fmt.Print("addDFAState " + d.String() + " exists") - } - return existing - } - - // The state was not present, so update it with configs - // - d.stateNumber = dfa.states.Len() - if !d.configs.ReadOnly() { - d.configs.OptimizeConfigs(p.BaseATNSimulator) - d.configs.SetReadOnly(true) - } - dfa.states.Put(d) - if ParserATNSimulatorTraceATNSim { - fmt.Println("addDFAState new " + d.String()) - } - - return d -} - -func (p *ParserATNSimulator) ReportAttemptingFullContext(dfa *DFA, conflictingAlts *BitSet, configs ATNConfigSet, startIndex, stopIndex int) { - if ParserATNSimulatorDebug || ParserATNSimulatorRetryDebug { - interval := NewInterval(startIndex, stopIndex+1) - fmt.Println("ReportAttemptingFullContext decision=" + strconv.Itoa(dfa.decision) + ":" + configs.String() + - ", input=" + p.parser.GetTokenStream().GetTextFromInterval(interval)) - } - if p.parser != nil { - p.parser.GetErrorListenerDispatch().ReportAttemptingFullContext(p.parser, dfa, startIndex, stopIndex, conflictingAlts, configs) - } -} - -func (p *ParserATNSimulator) ReportContextSensitivity(dfa *DFA, prediction int, configs ATNConfigSet, startIndex, stopIndex int) { - if ParserATNSimulatorDebug || ParserATNSimulatorRetryDebug { - interval := NewInterval(startIndex, stopIndex+1) - fmt.Println("ReportContextSensitivity decision=" + strconv.Itoa(dfa.decision) + ":" + configs.String() + - ", input=" + p.parser.GetTokenStream().GetTextFromInterval(interval)) - } - if p.parser != nil { - p.parser.GetErrorListenerDispatch().ReportContextSensitivity(p.parser, dfa, startIndex, stopIndex, prediction, configs) - } -} - -// If context sensitive parsing, we know it's ambiguity not conflict// -func (p *ParserATNSimulator) ReportAmbiguity(dfa *DFA, D *DFAState, startIndex, stopIndex int, - exact bool, ambigAlts *BitSet, configs ATNConfigSet) { - if ParserATNSimulatorDebug || ParserATNSimulatorRetryDebug { - interval := NewInterval(startIndex, stopIndex+1) - fmt.Println("ReportAmbiguity " + ambigAlts.String() + ":" + configs.String() + - ", input=" + p.parser.GetTokenStream().GetTextFromInterval(interval)) - } - if p.parser != nil { - p.parser.GetErrorListenerDispatch().ReportAmbiguity(p.parser, dfa, startIndex, stopIndex, exact, ambigAlts, configs) - } -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "fmt" + "strconv" + "strings" +) + +var ( + ParserATNSimulatorDebug = false + ParserATNSimulatorTraceATNSim = false + ParserATNSimulatorDFADebug = false + ParserATNSimulatorRetryDebug = false + TurnOffLRLoopEntryBranchOpt = false +) + +type ParserATNSimulator struct { + *BaseATNSimulator + + parser Parser + predictionMode int + input TokenStream + startIndex int + dfa *DFA + mergeCache *DoubleDict + outerContext ParserRuleContext +} + +func NewParserATNSimulator(parser Parser, atn *ATN, decisionToDFA []*DFA, sharedContextCache *PredictionContextCache) *ParserATNSimulator { + + p := new(ParserATNSimulator) + + p.BaseATNSimulator = NewBaseATNSimulator(atn, sharedContextCache) + + p.parser = parser + p.decisionToDFA = decisionToDFA + // SLL, LL, or LL + exact ambig detection?// + p.predictionMode = PredictionModeLL + // LAME globals to avoid parameters!!!!! I need these down deep in predTransition + p.input = nil + p.startIndex = 0 + p.outerContext = nil + p.dfa = nil + // Each prediction operation uses a cache for merge of prediction contexts. + // Don't keep around as it wastes huge amounts of memory. DoubleKeyMap + // isn't Synchronized but we're ok since two threads shouldn't reuse same + // parser/atnsim object because it can only handle one input at a time. + // This maps graphs a and b to merged result c. (a,b)&rarrc. We can avoid + // the merge if we ever see a and b again. Note that (b,a)&rarrc should + // also be examined during cache lookup. + // + p.mergeCache = nil + + return p +} + +func (p *ParserATNSimulator) GetPredictionMode() int { + return p.predictionMode +} + +func (p *ParserATNSimulator) SetPredictionMode(v int) { + p.predictionMode = v +} + +func (p *ParserATNSimulator) reset() { +} + +func (p *ParserATNSimulator) AdaptivePredict(input TokenStream, decision int, outerContext ParserRuleContext) int { + if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { + fmt.Println("adaptivePredict decision " + strconv.Itoa(decision) + + " exec LA(1)==" + p.getLookaheadName(input) + + " line " + strconv.Itoa(input.LT(1).GetLine()) + ":" + + strconv.Itoa(input.LT(1).GetColumn())) + } + + p.input = input + p.startIndex = input.Index() + p.outerContext = outerContext + + dfa := p.decisionToDFA[decision] + p.dfa = dfa + m := input.Mark() + index := input.Index() + + defer func() { + p.dfa = nil + p.mergeCache = nil // wack cache after each prediction + input.Seek(index) + input.Release(m) + }() + + // Now we are certain to have a specific decision's DFA + // But, do we still need an initial state? + var s0 *DFAState + p.atn.stateMu.RLock() + if dfa.getPrecedenceDfa() { + p.atn.edgeMu.RLock() + // the start state for a precedence DFA depends on the current + // parser precedence, and is provided by a DFA method. + s0 = dfa.getPrecedenceStartState(p.parser.GetPrecedence()) + p.atn.edgeMu.RUnlock() + } else { + // the start state for a "regular" DFA is just s0 + s0 = dfa.getS0() + } + p.atn.stateMu.RUnlock() + + if s0 == nil { + if outerContext == nil { + outerContext = ParserRuleContextEmpty + } + if ParserATNSimulatorDebug { + fmt.Println("predictATN decision " + strconv.Itoa(dfa.decision) + + " exec LA(1)==" + p.getLookaheadName(input) + + ", outerContext=" + outerContext.String(p.parser.GetRuleNames(), nil)) + } + fullCtx := false + s0Closure := p.computeStartState(dfa.atnStartState, ParserRuleContextEmpty, fullCtx) + + p.atn.stateMu.Lock() + if dfa.getPrecedenceDfa() { + // If p is a precedence DFA, we use applyPrecedenceFilter + // to convert the computed start state to a precedence start + // state. We then use DFA.setPrecedenceStartState to set the + // appropriate start state for the precedence level rather + // than simply setting DFA.s0. + // + dfa.s0.configs = s0Closure + s0Closure = p.applyPrecedenceFilter(s0Closure) + s0 = p.addDFAState(dfa, NewDFAState(-1, s0Closure)) + p.atn.edgeMu.Lock() + dfa.setPrecedenceStartState(p.parser.GetPrecedence(), s0) + p.atn.edgeMu.Unlock() + } else { + s0 = p.addDFAState(dfa, NewDFAState(-1, s0Closure)) + dfa.setS0(s0) + } + p.atn.stateMu.Unlock() + } + + alt := p.execATN(dfa, s0, input, index, outerContext) + if ParserATNSimulatorDebug { + fmt.Println("DFA after predictATN: " + dfa.String(p.parser.GetLiteralNames(), nil)) + } + return alt + +} + +// Performs ATN simulation to compute a predicted alternative based +// upon the remaining input, but also updates the DFA cache to avoid +// having to traverse the ATN again for the same input sequence. + +// There are some key conditions we're looking for after computing a new +// set of ATN configs (proposed DFA state): +// if the set is empty, there is no viable alternative for current symbol +// does the state uniquely predict an alternative? +// does the state have a conflict that would prevent us from +// putting it on the work list? + +// We also have some key operations to do: +// add an edge from previous DFA state to potentially NewDFA state, D, +// upon current symbol but only if adding to work list, which means in all +// cases except no viable alternative (and possibly non-greedy decisions?) +// collecting predicates and adding semantic context to DFA accept states +// adding rule context to context-sensitive DFA accept states +// consuming an input symbol +// Reporting a conflict +// Reporting an ambiguity +// Reporting a context sensitivity +// Reporting insufficient predicates + +// cover these cases: +// +// dead end +// single alt +// single alt + preds +// conflict +// conflict + preds +func (p *ParserATNSimulator) execATN(dfa *DFA, s0 *DFAState, input TokenStream, startIndex int, outerContext ParserRuleContext) int { + + if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { + fmt.Println("execATN decision " + strconv.Itoa(dfa.decision) + + ", DFA state " + s0.String() + + ", LA(1)==" + p.getLookaheadName(input) + + " line " + strconv.Itoa(input.LT(1).GetLine()) + ":" + strconv.Itoa(input.LT(1).GetColumn())) + } + + previousD := s0 + + if ParserATNSimulatorDebug { + fmt.Println("s0 = " + s0.String()) + } + t := input.LA(1) + for { // for more work + D := p.getExistingTargetState(previousD, t) + if D == nil { + D = p.computeTargetState(dfa, previousD, t) + } + if D == ATNSimulatorError { + // if any configs in previous dipped into outer context, that + // means that input up to t actually finished entry rule + // at least for SLL decision. Full LL doesn't dip into outer + // so don't need special case. + // We will get an error no matter what so delay until after + // decision better error message. Also, no reachable target + // ATN states in SLL implies LL will also get nowhere. + // If conflict in states that dip out, choose min since we + // will get error no matter what. + e := p.noViableAlt(input, outerContext, previousD.configs, startIndex) + input.Seek(startIndex) + alt := p.getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(previousD.configs, outerContext) + if alt != ATNInvalidAltNumber { + return alt + } + + panic(e) + } + if D.requiresFullContext && p.predictionMode != PredictionModeSLL { + // IF PREDS, MIGHT RESOLVE TO SINGLE ALT => SLL (or syntax error) + conflictingAlts := D.configs.GetConflictingAlts() + if D.predicates != nil { + if ParserATNSimulatorDebug { + fmt.Println("DFA state has preds in DFA sim LL failover") + } + conflictIndex := input.Index() + if conflictIndex != startIndex { + input.Seek(startIndex) + } + conflictingAlts = p.evalSemanticContext(D.predicates, outerContext, true) + if conflictingAlts.length() == 1 { + if ParserATNSimulatorDebug { + fmt.Println("Full LL avoided") + } + return conflictingAlts.minValue() + } + if conflictIndex != startIndex { + // restore the index so Reporting the fallback to full + // context occurs with the index at the correct spot + input.Seek(conflictIndex) + } + } + if ParserATNSimulatorDFADebug { + fmt.Println("ctx sensitive state " + outerContext.String(nil, nil) + " in " + D.String()) + } + fullCtx := true + s0Closure := p.computeStartState(dfa.atnStartState, outerContext, fullCtx) + p.ReportAttemptingFullContext(dfa, conflictingAlts, D.configs, startIndex, input.Index()) + alt := p.execATNWithFullContext(dfa, D, s0Closure, input, startIndex, outerContext) + return alt + } + if D.isAcceptState { + if D.predicates == nil { + return D.prediction + } + stopIndex := input.Index() + input.Seek(startIndex) + alts := p.evalSemanticContext(D.predicates, outerContext, true) + + switch alts.length() { + case 0: + panic(p.noViableAlt(input, outerContext, D.configs, startIndex)) + case 1: + return alts.minValue() + default: + // Report ambiguity after predicate evaluation to make sure the correct set of ambig alts is Reported. + p.ReportAmbiguity(dfa, D, startIndex, stopIndex, false, alts, D.configs) + return alts.minValue() + } + } + previousD = D + + if t != TokenEOF { + input.Consume() + t = input.LA(1) + } + } +} + +// Get an existing target state for an edge in the DFA. If the target state +// for the edge has not yet been computed or is otherwise not available, +// p method returns {@code nil}. +// +// @param previousD The current DFA state +// @param t The next input symbol +// @return The existing target DFA state for the given input symbol +// {@code t}, or {@code nil} if the target state for p edge is not +// already cached + +func (p *ParserATNSimulator) getExistingTargetState(previousD *DFAState, t int) *DFAState { + if t+1 < 0 { + return nil + } + + p.atn.edgeMu.RLock() + defer p.atn.edgeMu.RUnlock() + edges := previousD.getEdges() + if edges == nil || t+1 >= len(edges) { + return nil + } + return previousD.getIthEdge(t + 1) +} + +// Compute a target state for an edge in the DFA, and attempt to add the +// computed state and corresponding edge to the DFA. +// +// @param dfa The DFA +// @param previousD The current DFA state +// @param t The next input symbol +// +// @return The computed target DFA state for the given input symbol +// {@code t}. If {@code t} does not lead to a valid DFA state, p method +// returns {@link //ERROR}. + +func (p *ParserATNSimulator) computeTargetState(dfa *DFA, previousD *DFAState, t int) *DFAState { + reach := p.computeReachSet(previousD.configs, t, false) + + if reach == nil { + p.addDFAEdge(dfa, previousD, t, ATNSimulatorError) + return ATNSimulatorError + } + // create Newtarget state we'll add to DFA after it's complete + D := NewDFAState(-1, reach) + + predictedAlt := p.getUniqueAlt(reach) + + if ParserATNSimulatorDebug { + altSubSets := PredictionModegetConflictingAltSubsets(reach) + fmt.Println("SLL altSubSets=" + fmt.Sprint(altSubSets) + + ", previous=" + previousD.configs.String() + + ", configs=" + reach.String() + + ", predict=" + strconv.Itoa(predictedAlt) + + ", allSubsetsConflict=" + + fmt.Sprint(PredictionModeallSubsetsConflict(altSubSets)) + + ", conflictingAlts=" + p.getConflictingAlts(reach).String()) + } + if predictedAlt != ATNInvalidAltNumber { + // NO CONFLICT, UNIQUELY PREDICTED ALT + D.isAcceptState = true + D.configs.SetUniqueAlt(predictedAlt) + D.setPrediction(predictedAlt) + } else if PredictionModehasSLLConflictTerminatingPrediction(p.predictionMode, reach) { + // MORE THAN ONE VIABLE ALTERNATIVE + D.configs.SetConflictingAlts(p.getConflictingAlts(reach)) + D.requiresFullContext = true + // in SLL-only mode, we will stop at p state and return the minimum alt + D.isAcceptState = true + D.setPrediction(D.configs.GetConflictingAlts().minValue()) + } + if D.isAcceptState && D.configs.HasSemanticContext() { + p.predicateDFAState(D, p.atn.getDecisionState(dfa.decision)) + if D.predicates != nil { + D.setPrediction(ATNInvalidAltNumber) + } + } + // all adds to dfa are done after we've created full D state + D = p.addDFAEdge(dfa, previousD, t, D) + return D +} + +func (p *ParserATNSimulator) predicateDFAState(dfaState *DFAState, decisionState DecisionState) { + // We need to test all predicates, even in DFA states that + // uniquely predict alternative. + nalts := len(decisionState.GetTransitions()) + // Update DFA so reach becomes accept state with (predicate,alt) + // pairs if preds found for conflicting alts + altsToCollectPredsFrom := p.getConflictingAltsOrUniqueAlt(dfaState.configs) + altToPred := p.getPredsForAmbigAlts(altsToCollectPredsFrom, dfaState.configs, nalts) + if altToPred != nil { + dfaState.predicates = p.getPredicatePredictions(altsToCollectPredsFrom, altToPred) + dfaState.setPrediction(ATNInvalidAltNumber) // make sure we use preds + } else { + // There are preds in configs but they might go away + // when OR'd together like {p}? || NONE == NONE. If neither + // alt has preds, resolve to min alt + dfaState.setPrediction(altsToCollectPredsFrom.minValue()) + } +} + +// comes back with reach.uniqueAlt set to a valid alt +func (p *ParserATNSimulator) execATNWithFullContext(dfa *DFA, D *DFAState, s0 ATNConfigSet, input TokenStream, startIndex int, outerContext ParserRuleContext) int { + + if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { + fmt.Println("execATNWithFullContext " + s0.String()) + } + + fullCtx := true + foundExactAmbig := false + var reach ATNConfigSet + previous := s0 + input.Seek(startIndex) + t := input.LA(1) + predictedAlt := -1 + + for { // for more work + reach = p.computeReachSet(previous, t, fullCtx) + if reach == nil { + // if any configs in previous dipped into outer context, that + // means that input up to t actually finished entry rule + // at least for LL decision. Full LL doesn't dip into outer + // so don't need special case. + // We will get an error no matter what so delay until after + // decision better error message. Also, no reachable target + // ATN states in SLL implies LL will also get nowhere. + // If conflict in states that dip out, choose min since we + // will get error no matter what. + e := p.noViableAlt(input, outerContext, previous, startIndex) + input.Seek(startIndex) + alt := p.getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(previous, outerContext) + if alt != ATNInvalidAltNumber { + return alt + } + + panic(e) + } + altSubSets := PredictionModegetConflictingAltSubsets(reach) + if ParserATNSimulatorDebug { + fmt.Println("LL altSubSets=" + fmt.Sprint(altSubSets) + ", predict=" + + strconv.Itoa(PredictionModegetUniqueAlt(altSubSets)) + ", resolvesToJustOneViableAlt=" + + fmt.Sprint(PredictionModeresolvesToJustOneViableAlt(altSubSets))) + } + reach.SetUniqueAlt(p.getUniqueAlt(reach)) + // unique prediction? + if reach.GetUniqueAlt() != ATNInvalidAltNumber { + predictedAlt = reach.GetUniqueAlt() + break + } + if p.predictionMode != PredictionModeLLExactAmbigDetection { + predictedAlt = PredictionModeresolvesToJustOneViableAlt(altSubSets) + if predictedAlt != ATNInvalidAltNumber { + break + } + } else { + // In exact ambiguity mode, we never try to terminate early. + // Just keeps scarfing until we know what the conflict is + if PredictionModeallSubsetsConflict(altSubSets) && PredictionModeallSubsetsEqual(altSubSets) { + foundExactAmbig = true + predictedAlt = PredictionModegetSingleViableAlt(altSubSets) + break + } + // else there are multiple non-conflicting subsets or + // we're not sure what the ambiguity is yet. + // So, keep going. + } + previous = reach + if t != TokenEOF { + input.Consume() + t = input.LA(1) + } + } + // If the configuration set uniquely predicts an alternative, + // without conflict, then we know that it's a full LL decision + // not SLL. + if reach.GetUniqueAlt() != ATNInvalidAltNumber { + p.ReportContextSensitivity(dfa, predictedAlt, reach, startIndex, input.Index()) + return predictedAlt + } + // We do not check predicates here because we have checked them + // on-the-fly when doing full context prediction. + + // + // In non-exact ambiguity detection mode, we might actually be able to + // detect an exact ambiguity, but I'm not going to spend the cycles + // needed to check. We only emit ambiguity warnings in exact ambiguity + // mode. + // + // For example, we might know that we have conflicting configurations. + // But, that does not mean that there is no way forward without a + // conflict. It's possible to have nonconflicting alt subsets as in: + + // altSubSets=[{1, 2}, {1, 2}, {1}, {1, 2}] + + // from + // + // [(17,1,[5 $]), (13,1,[5 10 $]), (21,1,[5 10 $]), (11,1,[$]), + // (13,2,[5 10 $]), (21,2,[5 10 $]), (11,2,[$])] + // + // In p case, (17,1,[5 $]) indicates there is some next sequence that + // would resolve p without conflict to alternative 1. Any other viable + // next sequence, however, is associated with a conflict. We stop + // looking for input because no amount of further lookahead will alter + // the fact that we should predict alternative 1. We just can't say for + // sure that there is an ambiguity without looking further. + + p.ReportAmbiguity(dfa, D, startIndex, input.Index(), foundExactAmbig, reach.Alts(), reach) + + return predictedAlt +} + +func (p *ParserATNSimulator) computeReachSet(closure ATNConfigSet, t int, fullCtx bool) ATNConfigSet { + if p.mergeCache == nil { + p.mergeCache = NewDoubleDict() + } + intermediate := NewBaseATNConfigSet(fullCtx) + + // Configurations already in a rule stop state indicate reaching the end + // of the decision rule (local context) or end of the start rule (full + // context). Once reached, these configurations are never updated by a + // closure operation, so they are handled separately for the performance + // advantage of having a smaller intermediate set when calling closure. + // + // For full-context reach operations, separate handling is required to + // ensure that the alternative Matching the longest overall sequence is + // chosen when multiple such configurations can Match the input. + + var skippedStopStates []*BaseATNConfig + + // First figure out where we can reach on input t + for _, c := range closure.GetItems() { + if ParserATNSimulatorDebug { + fmt.Println("testing " + p.GetTokenName(t) + " at " + c.String()) + } + + if _, ok := c.GetState().(*RuleStopState); ok { + if fullCtx || t == TokenEOF { + skippedStopStates = append(skippedStopStates, c.(*BaseATNConfig)) + if ParserATNSimulatorDebug { + fmt.Println("added " + c.String() + " to SkippedStopStates") + } + } + continue + } + + for _, trans := range c.GetState().GetTransitions() { + target := p.getReachableTarget(trans, t) + if target != nil { + cfg := NewBaseATNConfig4(c, target) + intermediate.Add(cfg, p.mergeCache) + if ParserATNSimulatorDebug { + fmt.Println("added " + cfg.String() + " to intermediate") + } + } + } + } + + // Now figure out where the reach operation can take us... + var reach ATNConfigSet + + // This block optimizes the reach operation for intermediate sets which + // trivially indicate a termination state for the overall + // AdaptivePredict operation. + // + // The conditions assume that intermediate + // contains all configurations relevant to the reach set, but p + // condition is not true when one or more configurations have been + // withheld in SkippedStopStates, or when the current symbol is EOF. + // + if skippedStopStates == nil && t != TokenEOF { + if len(intermediate.configs) == 1 { + // Don't pursue the closure if there is just one state. + // It can only have one alternative just add to result + // Also don't pursue the closure if there is unique alternative + // among the configurations. + reach = intermediate + } else if p.getUniqueAlt(intermediate) != ATNInvalidAltNumber { + // Also don't pursue the closure if there is unique alternative + // among the configurations. + reach = intermediate + } + } + // If the reach set could not be trivially determined, perform a closure + // operation on the intermediate set to compute its initial value. + // + if reach == nil { + reach = NewBaseATNConfigSet(fullCtx) + closureBusy := NewJStore[ATNConfig, Comparator[ATNConfig]](aConfEqInst) + treatEOFAsEpsilon := t == TokenEOF + amount := len(intermediate.configs) + for k := 0; k < amount; k++ { + p.closure(intermediate.configs[k], reach, closureBusy, false, fullCtx, treatEOFAsEpsilon) + } + } + if t == TokenEOF { + // After consuming EOF no additional input is possible, so we are + // only interested in configurations which reached the end of the + // decision rule (local context) or end of the start rule (full + // context). Update reach to contain only these configurations. This + // handles both explicit EOF transitions in the grammar and implicit + // EOF transitions following the end of the decision or start rule. + // + // When reach==intermediate, no closure operation was performed. In + // p case, removeAllConfigsNotInRuleStopState needs to check for + // reachable rule stop states as well as configurations already in + // a rule stop state. + // + // This is handled before the configurations in SkippedStopStates, + // because any configurations potentially added from that list are + // already guaranteed to meet p condition whether or not it's + // required. + // + reach = p.removeAllConfigsNotInRuleStopState(reach, reach == intermediate) + } + // If SkippedStopStates!=nil, then it contains at least one + // configuration. For full-context reach operations, these + // configurations reached the end of the start rule, in which case we + // only add them back to reach if no configuration during the current + // closure operation reached such a state. This ensures AdaptivePredict + // chooses an alternative Matching the longest overall sequence when + // multiple alternatives are viable. + // + if skippedStopStates != nil && ((!fullCtx) || (!PredictionModehasConfigInRuleStopState(reach))) { + for l := 0; l < len(skippedStopStates); l++ { + reach.Add(skippedStopStates[l], p.mergeCache) + } + } + + if ParserATNSimulatorTraceATNSim { + fmt.Println("computeReachSet " + closure.String() + " -> " + reach.String()) + } + + if len(reach.GetItems()) == 0 { + return nil + } + + return reach +} + +// Return a configuration set containing only the configurations from +// {@code configs} which are in a {@link RuleStopState}. If all +// configurations in {@code configs} are already in a rule stop state, p +// method simply returns {@code configs}. +// +//When {@code lookToEndOfRule} is true, p method uses +// {@link ATN//NextTokens} for each configuration in {@code configs} which is +// not already in a rule stop state to see if a rule stop state is reachable +// from the configuration via epsilon-only transitions.
+// +// @param configs the configuration set to update +// @param lookToEndOfRule when true, p method checks for rule stop states +// reachable by epsilon-only transitions from each configuration in +// {@code configs}. +// +// @return {@code configs} if all configurations in {@code configs} are in a +// rule stop state, otherwise return a Newconfiguration set containing only +// the configurations from {@code configs} which are in a rule stop state +func (p *ParserATNSimulator) removeAllConfigsNotInRuleStopState(configs ATNConfigSet, lookToEndOfRule bool) ATNConfigSet { + if PredictionModeallConfigsInRuleStopStates(configs) { + return configs + } + result := NewBaseATNConfigSet(configs.FullContext()) + for _, config := range configs.GetItems() { + if _, ok := config.GetState().(*RuleStopState); ok { + result.Add(config, p.mergeCache) + continue + } + if lookToEndOfRule && config.GetState().GetEpsilonOnlyTransitions() { + NextTokens := p.atn.NextTokens(config.GetState(), nil) + if NextTokens.contains(TokenEpsilon) { + endOfRuleState := p.atn.ruleToStopState[config.GetState().GetRuleIndex()] + result.Add(NewBaseATNConfig4(config, endOfRuleState), p.mergeCache) + } + } + } + return result +} + +func (p *ParserATNSimulator) computeStartState(a ATNState, ctx RuleContext, fullCtx bool) ATNConfigSet { + // always at least the implicit call to start rule + initialContext := predictionContextFromRuleContext(p.atn, ctx) + configs := NewBaseATNConfigSet(fullCtx) + if ParserATNSimulatorDebug || ParserATNSimulatorTraceATNSim { + fmt.Println("computeStartState from ATN state " + a.String() + + " initialContext=" + initialContext.String()) + } + + for i := 0; i < len(a.GetTransitions()); i++ { + target := a.GetTransitions()[i].getTarget() + c := NewBaseATNConfig6(target, i+1, initialContext) + closureBusy := NewJStore[ATNConfig, Comparator[ATNConfig]](atnConfCompInst) + p.closure(c, configs, closureBusy, true, fullCtx, false) + } + return configs +} + +// This method transforms the start state computed by +// {@link //computeStartState} to the special start state used by a +// precedence DFA for a particular precedence value. The transformation +// process applies the following changes to the start state's configuration +// set. +// +//-
+//
- Evaluate the precedence predicates for each configuration using +// {@link SemanticContext//evalPrecedence}. +//
- Remove all configurations which predict an alternative greater than
+// 1, for which another configuration that predicts alternative 1 is in the
+// same ATN state with the same prediction context. This transformation is
+// valid for the following reasons:
+//
-
+//
- The closure block cannot contain any epsilon transitions which bypass +// the body of the closure, so all states reachable via alternative 1 are +// part of the precedence alternatives of the transformed left-recursive +// rule. +//
- The "primary" portion of a left recursive rule cannot contain an +// epsilon transition, so the only way an alternative other than 1 can exist +// in a state that is also reachable via alternative 1 is by nesting calls +// to the left-recursive rule, with the outer calls not being at the +// preferred precedence level. +//
+//
+// The prediction context must be considered by p filter to address +// situations like the following. +//
+//
+//
+// grammar TA
+// prog: statement* EOF
+// statement: letterA | statement letterA 'b'
+// letterA: 'a'
+//
+//
+// +// If the above grammar, the ATN state immediately before the token +// reference {@code 'a'} in {@code letterA} is reachable from the left edge +// of both the primary and closure blocks of the left-recursive rule +// {@code statement}. The prediction context associated with each of these +// configurations distinguishes between them, and prevents the alternative +// which stepped out to {@code prog} (and then back in to {@code statement} +// from being eliminated by the filter. +//
+// +// @param configs The configuration set computed by +// {@link //computeStartState} as the start state for the DFA. +// @return The transformed configuration set representing the start state +// for a precedence DFA at a particular precedence level (determined by +// calling {@link Parser//getPrecedence}). +func (p *ParserATNSimulator) applyPrecedenceFilter(configs ATNConfigSet) ATNConfigSet { + + statesFromAlt1 := make(map[int]PredictionContext) + configSet := NewBaseATNConfigSet(configs.FullContext()) + + for _, config := range configs.GetItems() { + // handle alt 1 first + if config.GetAlt() != 1 { + continue + } + updatedContext := config.GetSemanticContext().evalPrecedence(p.parser, p.outerContext) + if updatedContext == nil { + // the configuration was eliminated + continue + } + statesFromAlt1[config.GetState().GetStateNumber()] = config.GetContext() + if updatedContext != config.GetSemanticContext() { + configSet.Add(NewBaseATNConfig2(config, updatedContext), p.mergeCache) + } else { + configSet.Add(config, p.mergeCache) + } + } + for _, config := range configs.GetItems() { + + if config.GetAlt() == 1 { + // already handled + continue + } + // In the future, p elimination step could be updated to also + // filter the prediction context for alternatives predicting alt>1 + // (basically a graph subtraction algorithm). + if !config.getPrecedenceFilterSuppressed() { + context := statesFromAlt1[config.GetState().GetStateNumber()] + if context != nil && context.Equals(config.GetContext()) { + // eliminated + continue + } + } + configSet.Add(config, p.mergeCache) + } + return configSet +} + +func (p *ParserATNSimulator) getReachableTarget(trans Transition, ttype int) ATNState { + if trans.Matches(ttype, 0, p.atn.maxTokenType) { + return trans.getTarget() + } + + return nil +} + +func (p *ParserATNSimulator) getPredsForAmbigAlts(ambigAlts *BitSet, configs ATNConfigSet, nalts int) []SemanticContext { + + altToPred := make([]SemanticContext, nalts+1) + for _, c := range configs.GetItems() { + if ambigAlts.contains(c.GetAlt()) { + altToPred[c.GetAlt()] = SemanticContextorContext(altToPred[c.GetAlt()], c.GetSemanticContext()) + } + } + nPredAlts := 0 + for i := 1; i <= nalts; i++ { + pred := altToPred[i] + if pred == nil { + altToPred[i] = SemanticContextNone + } else if pred != SemanticContextNone { + nPredAlts++ + } + } + // nonambig alts are nil in altToPred + if nPredAlts == 0 { + altToPred = nil + } + if ParserATNSimulatorDebug { + fmt.Println("getPredsForAmbigAlts result " + fmt.Sprint(altToPred)) + } + return altToPred +} + +func (p *ParserATNSimulator) getPredicatePredictions(ambigAlts *BitSet, altToPred []SemanticContext) []*PredPrediction { + pairs := make([]*PredPrediction, 0) + containsPredicate := false + for i := 1; i < len(altToPred); i++ { + pred := altToPred[i] + // unpredicated is indicated by SemanticContextNONE + if ambigAlts != nil && ambigAlts.contains(i) { + pairs = append(pairs, NewPredPrediction(pred, i)) + } + if pred != SemanticContextNone { + containsPredicate = true + } + } + if !containsPredicate { + return nil + } + return pairs +} + +// This method is used to improve the localization of error messages by +// choosing an alternative rather than panicing a +// {@link NoViableAltException} in particular prediction scenarios where the +// {@link //ERROR} state was reached during ATN simulation. +// +//+// The default implementation of p method uses the following +// algorithm to identify an ATN configuration which successfully parsed the +// decision entry rule. Choosing such an alternative ensures that the +// {@link ParserRuleContext} returned by the calling rule will be complete +// and valid, and the syntax error will be Reported later at a more +// localized location.
+// +//-
+//
- If a syntactically valid path or paths reach the end of the decision rule and +// they are semantically valid if predicated, return the min associated alt. +//
- Else, if a semantically invalid but syntactically valid path exist +// or paths exist, return the minimum associated alt. +// +//
- Otherwise, return {@link ATN//INVALID_ALT_NUMBER}. +//
+// In some scenarios, the algorithm described above could predict an +// alternative which will result in a {@link FailedPredicateException} in +// the parser. Specifically, p could occur if the only configuration +// capable of successfully parsing to the end of the decision rule is +// blocked by a semantic predicate. By choosing p alternative within +// {@link //AdaptivePredict} instead of panicing a +// {@link NoViableAltException}, the resulting +// {@link FailedPredicateException} in the parser will identify the specific +// predicate which is preventing the parser from successfully parsing the +// decision rule, which helps developers identify and correct logic errors +// in semantic predicates. +//
+// +// @param configs The ATN configurations which were valid immediately before +// the {@link //ERROR} state was reached +// @param outerContext The is the \gamma_0 initial parser context from the paper +// or the parser stack at the instant before prediction commences. +// +// @return The value to return from {@link //AdaptivePredict}, or +// {@link ATN//INVALID_ALT_NUMBER} if a suitable alternative was not +// identified and {@link //AdaptivePredict} should Report an error instead. +func (p *ParserATNSimulator) getSynValidOrSemInvalidAltThatFinishedDecisionEntryRule(configs ATNConfigSet, outerContext ParserRuleContext) int { + cfgs := p.splitAccordingToSemanticValidity(configs, outerContext) + semValidConfigs := cfgs[0] + semInvalidConfigs := cfgs[1] + alt := p.GetAltThatFinishedDecisionEntryRule(semValidConfigs) + if alt != ATNInvalidAltNumber { // semantically/syntactically viable path exists + return alt + } + // Is there a syntactically valid path with a failed pred? + if len(semInvalidConfigs.GetItems()) > 0 { + alt = p.GetAltThatFinishedDecisionEntryRule(semInvalidConfigs) + if alt != ATNInvalidAltNumber { // syntactically viable path exists + return alt + } + } + return ATNInvalidAltNumber +} + +func (p *ParserATNSimulator) GetAltThatFinishedDecisionEntryRule(configs ATNConfigSet) int { + alts := NewIntervalSet() + + for _, c := range configs.GetItems() { + _, ok := c.GetState().(*RuleStopState) + + if c.GetReachesIntoOuterContext() > 0 || (ok && c.GetContext().hasEmptyPath()) { + alts.addOne(c.GetAlt()) + } + } + if alts.length() == 0 { + return ATNInvalidAltNumber + } + + return alts.first() +} + +// Walk the list of configurations and split them according to +// those that have preds evaluating to true/false. If no pred, assume +// true pred and include in succeeded set. Returns Pair of sets. +// +// Create a NewSet so as not to alter the incoming parameter. +// +// Assumption: the input stream has been restored to the starting point +// prediction, which is where predicates need to evaluate. + +type ATNConfigSetPair struct { + item0, item1 ATNConfigSet +} + +func (p *ParserATNSimulator) splitAccordingToSemanticValidity(configs ATNConfigSet, outerContext ParserRuleContext) []ATNConfigSet { + succeeded := NewBaseATNConfigSet(configs.FullContext()) + failed := NewBaseATNConfigSet(configs.FullContext()) + + for _, c := range configs.GetItems() { + if c.GetSemanticContext() != SemanticContextNone { + predicateEvaluationResult := c.GetSemanticContext().evaluate(p.parser, outerContext) + if predicateEvaluationResult { + succeeded.Add(c, nil) + } else { + failed.Add(c, nil) + } + } else { + succeeded.Add(c, nil) + } + } + return []ATNConfigSet{succeeded, failed} +} + +// Look through a list of predicate/alt pairs, returning alts for the +// +// pairs that win. A {@code NONE} predicate indicates an alt containing an +// unpredicated config which behaves as "always true." If !complete +// then we stop at the first predicate that evaluates to true. This +// includes pairs with nil predicates. +func (p *ParserATNSimulator) evalSemanticContext(predPredictions []*PredPrediction, outerContext ParserRuleContext, complete bool) *BitSet { + predictions := NewBitSet() + for i := 0; i < len(predPredictions); i++ { + pair := predPredictions[i] + if pair.pred == SemanticContextNone { + predictions.add(pair.alt) + if !complete { + break + } + continue + } + + predicateEvaluationResult := pair.pred.evaluate(p.parser, outerContext) + if ParserATNSimulatorDebug || ParserATNSimulatorDFADebug { + fmt.Println("eval pred " + pair.String() + "=" + fmt.Sprint(predicateEvaluationResult)) + } + if predicateEvaluationResult { + if ParserATNSimulatorDebug || ParserATNSimulatorDFADebug { + fmt.Println("PREDICT " + fmt.Sprint(pair.alt)) + } + predictions.add(pair.alt) + if !complete { + break + } + } + } + return predictions +} + +func (p *ParserATNSimulator) closure(config ATNConfig, configs ATNConfigSet, closureBusy *JStore[ATNConfig, Comparator[ATNConfig]], collectPredicates, fullCtx, treatEOFAsEpsilon bool) { + initialDepth := 0 + p.closureCheckingStopState(config, configs, closureBusy, collectPredicates, + fullCtx, initialDepth, treatEOFAsEpsilon) +} + +func (p *ParserATNSimulator) closureCheckingStopState(config ATNConfig, configs ATNConfigSet, closureBusy *JStore[ATNConfig, Comparator[ATNConfig]], collectPredicates, fullCtx bool, depth int, treatEOFAsEpsilon bool) { + if ParserATNSimulatorTraceATNSim { + fmt.Println("closure(" + config.String() + ")") + //fmt.Println("configs(" + configs.String() + ")") + if config.GetReachesIntoOuterContext() > 50 { + panic("problem") + } + } + + if _, ok := config.GetState().(*RuleStopState); ok { + // We hit rule end. If we have context info, use it + // run thru all possible stack tops in ctx + if !config.GetContext().isEmpty() { + for i := 0; i < config.GetContext().length(); i++ { + if config.GetContext().getReturnState(i) == BasePredictionContextEmptyReturnState { + if fullCtx { + configs.Add(NewBaseATNConfig1(config, config.GetState(), BasePredictionContextEMPTY), p.mergeCache) + continue + } else { + // we have no context info, just chase follow links (if greedy) + if ParserATNSimulatorDebug { + fmt.Println("FALLING off rule " + p.getRuleName(config.GetState().GetRuleIndex())) + } + p.closureWork(config, configs, closureBusy, collectPredicates, fullCtx, depth, treatEOFAsEpsilon) + } + continue + } + returnState := p.atn.states[config.GetContext().getReturnState(i)] + newContext := config.GetContext().GetParent(i) // "pop" return state + + c := NewBaseATNConfig5(returnState, config.GetAlt(), newContext, config.GetSemanticContext()) + // While we have context to pop back from, we may have + // gotten that context AFTER having falling off a rule. + // Make sure we track that we are now out of context. + c.SetReachesIntoOuterContext(config.GetReachesIntoOuterContext()) + p.closureCheckingStopState(c, configs, closureBusy, collectPredicates, fullCtx, depth-1, treatEOFAsEpsilon) + } + return + } else if fullCtx { + // reached end of start rule + configs.Add(config, p.mergeCache) + return + } else { + // else if we have no context info, just chase follow links (if greedy) + if ParserATNSimulatorDebug { + fmt.Println("FALLING off rule " + p.getRuleName(config.GetState().GetRuleIndex())) + } + } + } + p.closureWork(config, configs, closureBusy, collectPredicates, fullCtx, depth, treatEOFAsEpsilon) +} + +// Do the actual work of walking epsilon edges// +func (p *ParserATNSimulator) closureWork(config ATNConfig, configs ATNConfigSet, closureBusy *JStore[ATNConfig, Comparator[ATNConfig]], collectPredicates, fullCtx bool, depth int, treatEOFAsEpsilon bool) { + state := config.GetState() + // optimization + if !state.GetEpsilonOnlyTransitions() { + configs.Add(config, p.mergeCache) + // make sure to not return here, because EOF transitions can act as + // both epsilon transitions and non-epsilon transitions. + } + for i := 0; i < len(state.GetTransitions()); i++ { + if i == 0 && p.canDropLoopEntryEdgeInLeftRecursiveRule(config) { + continue + } + + t := state.GetTransitions()[i] + _, ok := t.(*ActionTransition) + continueCollecting := collectPredicates && !ok + c := p.getEpsilonTarget(config, t, continueCollecting, depth == 0, fullCtx, treatEOFAsEpsilon) + if ci, ok := c.(*BaseATNConfig); ok && ci != nil { + newDepth := depth + + if _, ok := config.GetState().(*RuleStopState); ok { + // target fell off end of rule mark resulting c as having dipped into outer context + // We can't get here if incoming config was rule stop and we had context + // track how far we dip into outer context. Might + // come in handy and we avoid evaluating context dependent + // preds if p is > 0. + + if p.dfa != nil && p.dfa.getPrecedenceDfa() { + if t.(*EpsilonTransition).outermostPrecedenceReturn == p.dfa.atnStartState.GetRuleIndex() { + c.setPrecedenceFilterSuppressed(true) + } + } + + c.SetReachesIntoOuterContext(c.GetReachesIntoOuterContext() + 1) + + _, present := closureBusy.Put(c) + if present { + // avoid infinite recursion for right-recursive rules + continue + } + + configs.SetDipsIntoOuterContext(true) // TODO: can remove? only care when we add to set per middle of p method + newDepth-- + if ParserATNSimulatorDebug { + fmt.Println("dips into outer ctx: " + c.String()) + } + } else { + + if !t.getIsEpsilon() { + _, present := closureBusy.Put(c) + if present { + // avoid infinite recursion for EOF* and EOF+ + continue + } + } + if _, ok := t.(*RuleTransition); ok { + // latch when newDepth goes negative - once we step out of the entry context we can't return + if newDepth >= 0 { + newDepth++ + } + } + } + p.closureCheckingStopState(c, configs, closureBusy, continueCollecting, fullCtx, newDepth, treatEOFAsEpsilon) + } + } +} + +func (p *ParserATNSimulator) canDropLoopEntryEdgeInLeftRecursiveRule(config ATNConfig) bool { + if TurnOffLRLoopEntryBranchOpt { + return false + } + + _p := config.GetState() + + // First check to see if we are in StarLoopEntryState generated during + // left-recursion elimination. For efficiency, also check if + // the context has an empty stack case. If so, it would mean + // global FOLLOW so we can't perform optimization + if _p.GetStateType() != ATNStateStarLoopEntry { + return false + } + startLoop, ok := _p.(*StarLoopEntryState) + if !ok { + return false + } + if !startLoop.precedenceRuleDecision || + config.GetContext().isEmpty() || + config.GetContext().hasEmptyPath() { + return false + } + + // Require all return states to return back to the same rule + // that p is in. + numCtxs := config.GetContext().length() + for i := 0; i < numCtxs; i++ { + returnState := p.atn.states[config.GetContext().getReturnState(i)] + if returnState.GetRuleIndex() != _p.GetRuleIndex() { + return false + } + } + x := _p.GetTransitions()[0].getTarget() + decisionStartState := x.(BlockStartState) + blockEndStateNum := decisionStartState.getEndState().stateNumber + blockEndState := p.atn.states[blockEndStateNum].(*BlockEndState) + + // Verify that the top of each stack context leads to loop entry/exit + // state through epsilon edges and w/o leaving rule. + + for i := 0; i < numCtxs; i++ { // for each stack context + returnStateNumber := config.GetContext().getReturnState(i) + returnState := p.atn.states[returnStateNumber] + + // all states must have single outgoing epsilon edge + if len(returnState.GetTransitions()) != 1 || !returnState.GetTransitions()[0].getIsEpsilon() { + return false + } + + // Look for prefix op case like 'not expr', (' type ')' expr + returnStateTarget := returnState.GetTransitions()[0].getTarget() + if returnState.GetStateType() == ATNStateBlockEnd && returnStateTarget == _p { + continue + } + + // Look for 'expr op expr' or case where expr's return state is block end + // of (...)* internal block; the block end points to loop back + // which points to p but we don't need to check that + if returnState == blockEndState { + continue + } + + // Look for ternary expr ? expr : expr. The return state points at block end, + // which points at loop entry state + if returnStateTarget == blockEndState { + continue + } + + // Look for complex prefix 'between expr and expr' case where 2nd expr's + // return state points at block end state of (...)* internal block + if returnStateTarget.GetStateType() == ATNStateBlockEnd && + len(returnStateTarget.GetTransitions()) == 1 && + returnStateTarget.GetTransitions()[0].getIsEpsilon() && + returnStateTarget.GetTransitions()[0].getTarget() == _p { + continue + } + + // anything else ain't conforming + return false + } + + return true +} + +func (p *ParserATNSimulator) getRuleName(index int) string { + if p.parser != nil && index >= 0 { + return p.parser.GetRuleNames()[index] + } + var sb strings.Builder + sb.Grow(32) + + sb.WriteString("If {@code to} is {@code nil}, p method returns {@code nil}. +// Otherwise, p method returns the {@link DFAState} returned by calling +// {@link //addDFAState} for the {@code to} state.
+// +// @param dfa The DFA +// @param from The source state for the edge +// @param t The input symbol +// @param to The target state for the edge +// +// @return If {@code to} is {@code nil}, p method returns {@code nil} +// otherwise p method returns the result of calling {@link //addDFAState} +// on {@code to} +func (p *ParserATNSimulator) addDFAEdge(dfa *DFA, from *DFAState, t int, to *DFAState) *DFAState { + if ParserATNSimulatorDebug { + fmt.Println("EDGE " + from.String() + " -> " + to.String() + " upon " + p.GetTokenName(t)) + } + if to == nil { + return nil + } + p.atn.stateMu.Lock() + to = p.addDFAState(dfa, to) // used existing if possible not incoming + p.atn.stateMu.Unlock() + if from == nil || t < -1 || t > p.atn.maxTokenType { + return to + } + p.atn.edgeMu.Lock() + if from.getEdges() == nil { + from.setEdges(make([]*DFAState, p.atn.maxTokenType+1+1)) + } + from.setIthEdge(t+1, to) // connect + p.atn.edgeMu.Unlock() + + if ParserATNSimulatorDebug { + var names []string + if p.parser != nil { + names = p.parser.GetLiteralNames() + } + + fmt.Println("DFA=\n" + dfa.String(names, nil)) + } + return to +} + +// Add state {@code D} to the DFA if it is not already present, and return +// the actual instance stored in the DFA. If a state equivalent to {@code D} +// is already in the DFA, the existing state is returned. Otherwise p +// method returns {@code D} after adding it to the DFA. +// +//If {@code D} is {@link //ERROR}, p method returns {@link //ERROR} and +// does not change the DFA.
+// +// @param dfa The dfa +// @param D The DFA state to add +// @return The state stored in the DFA. This will be either the existing +// state if {@code D} is already in the DFA, or {@code D} itself if the +// state was not already present. +func (p *ParserATNSimulator) addDFAState(dfa *DFA, d *DFAState) *DFAState { + if d == ATNSimulatorError { + return d + } + existing, present := dfa.states.Get(d) + if present { + if ParserATNSimulatorTraceATNSim { + fmt.Print("addDFAState " + d.String() + " exists") + } + return existing + } + + // The state was not present, so update it with configs + // + d.stateNumber = dfa.states.Len() + if !d.configs.ReadOnly() { + d.configs.OptimizeConfigs(p.BaseATNSimulator) + d.configs.SetReadOnly(true) + } + dfa.states.Put(d) + if ParserATNSimulatorTraceATNSim { + fmt.Println("addDFAState new " + d.String()) + } + + return d +} + +func (p *ParserATNSimulator) ReportAttemptingFullContext(dfa *DFA, conflictingAlts *BitSet, configs ATNConfigSet, startIndex, stopIndex int) { + if ParserATNSimulatorDebug || ParserATNSimulatorRetryDebug { + interval := NewInterval(startIndex, stopIndex+1) + fmt.Println("ReportAttemptingFullContext decision=" + strconv.Itoa(dfa.decision) + ":" + configs.String() + + ", input=" + p.parser.GetTokenStream().GetTextFromInterval(interval)) + } + if p.parser != nil { + p.parser.GetErrorListenerDispatch().ReportAttemptingFullContext(p.parser, dfa, startIndex, stopIndex, conflictingAlts, configs) + } +} + +func (p *ParserATNSimulator) ReportContextSensitivity(dfa *DFA, prediction int, configs ATNConfigSet, startIndex, stopIndex int) { + if ParserATNSimulatorDebug || ParserATNSimulatorRetryDebug { + interval := NewInterval(startIndex, stopIndex+1) + fmt.Println("ReportContextSensitivity decision=" + strconv.Itoa(dfa.decision) + ":" + configs.String() + + ", input=" + p.parser.GetTokenStream().GetTextFromInterval(interval)) + } + if p.parser != nil { + p.parser.GetErrorListenerDispatch().ReportContextSensitivity(p.parser, dfa, startIndex, stopIndex, prediction, configs) + } +} + +// If context sensitive parsing, we know it's ambiguity not conflict// +func (p *ParserATNSimulator) ReportAmbiguity(dfa *DFA, D *DFAState, startIndex, stopIndex int, + exact bool, ambigAlts *BitSet, configs ATNConfigSet) { + if ParserATNSimulatorDebug || ParserATNSimulatorRetryDebug { + interval := NewInterval(startIndex, stopIndex+1) + fmt.Println("ReportAmbiguity " + ambigAlts.String() + ":" + configs.String() + + ", input=" + p.parser.GetTokenStream().GetTextFromInterval(interval)) + } + if p.parser != nil { + p.parser.GetErrorListenerDispatch().ReportAmbiguity(p.parser, dfa, startIndex, stopIndex, exact, ambigAlts, configs) + } +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_rule_context.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_rule_context.go index 1c8cee7479..1d26d239bd 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_rule_context.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/parser_rule_context.go @@ -1,362 +1,362 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "reflect" - "strconv" -) - -type ParserRuleContext interface { - RuleContext - - SetException(RecognitionException) - - AddTokenNode(token Token) *TerminalNodeImpl - AddErrorNode(badToken Token) *ErrorNodeImpl - - EnterRule(listener ParseTreeListener) - ExitRule(listener ParseTreeListener) - - SetStart(Token) - GetStart() Token - - SetStop(Token) - GetStop() Token - - AddChild(child RuleContext) RuleContext - RemoveLastChild() -} - -type BaseParserRuleContext struct { - *BaseRuleContext - - start, stop Token - exception RecognitionException - children []Tree -} - -func NewBaseParserRuleContext(parent ParserRuleContext, invokingStateNumber int) *BaseParserRuleContext { - prc := new(BaseParserRuleContext) - - prc.BaseRuleContext = NewBaseRuleContext(parent, invokingStateNumber) - - prc.RuleIndex = -1 - // * If we are debugging or building a parse tree for a Visitor, - // we need to track all of the tokens and rule invocations associated - // with prc rule's context. This is empty for parsing w/o tree constr. - // operation because we don't the need to track the details about - // how we parse prc rule. - // / - prc.children = nil - prc.start = nil - prc.stop = nil - // The exception that forced prc rule to return. If the rule successfully - // completed, prc is {@code nil}. - prc.exception = nil - - return prc -} - -func (prc *BaseParserRuleContext) SetException(e RecognitionException) { - prc.exception = e -} - -func (prc *BaseParserRuleContext) GetChildren() []Tree { - return prc.children -} - -func (prc *BaseParserRuleContext) CopyFrom(ctx *BaseParserRuleContext) { - // from RuleContext - prc.parentCtx = ctx.parentCtx - prc.invokingState = ctx.invokingState - prc.children = nil - prc.start = ctx.start - prc.stop = ctx.stop -} - -func (prc *BaseParserRuleContext) GetText() string { - if prc.GetChildCount() == 0 { - return "" - } - - var s string - for _, child := range prc.children { - s += child.(ParseTree).GetText() - } - - return s -} - -// Double dispatch methods for listeners -func (prc *BaseParserRuleContext) EnterRule(listener ParseTreeListener) { -} - -func (prc *BaseParserRuleContext) ExitRule(listener ParseTreeListener) { -} - -// * Does not set parent link other add methods do that/// -func (prc *BaseParserRuleContext) addTerminalNodeChild(child TerminalNode) TerminalNode { - if prc.children == nil { - prc.children = make([]Tree, 0) - } - if child == nil { - panic("Child may not be null") - } - prc.children = append(prc.children, child) - return child -} - -func (prc *BaseParserRuleContext) AddChild(child RuleContext) RuleContext { - if prc.children == nil { - prc.children = make([]Tree, 0) - } - if child == nil { - panic("Child may not be null") - } - prc.children = append(prc.children, child) - return child -} - -// * Used by EnterOuterAlt to toss out a RuleContext previously added as -// we entered a rule. If we have // label, we will need to remove -// generic ruleContext object. -// / -func (prc *BaseParserRuleContext) RemoveLastChild() { - if prc.children != nil && len(prc.children) > 0 { - prc.children = prc.children[0 : len(prc.children)-1] - } -} - -func (prc *BaseParserRuleContext) AddTokenNode(token Token) *TerminalNodeImpl { - - node := NewTerminalNodeImpl(token) - prc.addTerminalNodeChild(node) - node.parentCtx = prc - return node - -} - -func (prc *BaseParserRuleContext) AddErrorNode(badToken Token) *ErrorNodeImpl { - node := NewErrorNodeImpl(badToken) - prc.addTerminalNodeChild(node) - node.parentCtx = prc - return node -} - -func (prc *BaseParserRuleContext) GetChild(i int) Tree { - if prc.children != nil && len(prc.children) >= i { - return prc.children[i] - } - - return nil -} - -func (prc *BaseParserRuleContext) GetChildOfType(i int, childType reflect.Type) RuleContext { - if childType == nil { - return prc.GetChild(i).(RuleContext) - } - - for j := 0; j < len(prc.children); j++ { - child := prc.children[j] - if reflect.TypeOf(child) == childType { - if i == 0 { - return child.(RuleContext) - } - - i-- - } - } - - return nil -} - -func (prc *BaseParserRuleContext) ToStringTree(ruleNames []string, recog Recognizer) string { - return TreesStringTree(prc, ruleNames, recog) -} - -func (prc *BaseParserRuleContext) GetRuleContext() RuleContext { - return prc -} - -func (prc *BaseParserRuleContext) Accept(visitor ParseTreeVisitor) interface{} { - return visitor.VisitChildren(prc) -} - -func (prc *BaseParserRuleContext) SetStart(t Token) { - prc.start = t -} - -func (prc *BaseParserRuleContext) GetStart() Token { - return prc.start -} - -func (prc *BaseParserRuleContext) SetStop(t Token) { - prc.stop = t -} - -func (prc *BaseParserRuleContext) GetStop() Token { - return prc.stop -} - -func (prc *BaseParserRuleContext) GetToken(ttype int, i int) TerminalNode { - - for j := 0; j < len(prc.children); j++ { - child := prc.children[j] - if c2, ok := child.(TerminalNode); ok { - if c2.GetSymbol().GetTokenType() == ttype { - if i == 0 { - return c2 - } - - i-- - } - } - } - return nil -} - -func (prc *BaseParserRuleContext) GetTokens(ttype int) []TerminalNode { - if prc.children == nil { - return make([]TerminalNode, 0) - } - - tokens := make([]TerminalNode, 0) - - for j := 0; j < len(prc.children); j++ { - child := prc.children[j] - if tchild, ok := child.(TerminalNode); ok { - if tchild.GetSymbol().GetTokenType() == ttype { - tokens = append(tokens, tchild) - } - } - } - - return tokens -} - -func (prc *BaseParserRuleContext) GetPayload() interface{} { - return prc -} - -func (prc *BaseParserRuleContext) getChild(ctxType reflect.Type, i int) RuleContext { - if prc.children == nil || i < 0 || i >= len(prc.children) { - return nil - } - - j := -1 // what element have we found with ctxType? - for _, o := range prc.children { - - childType := reflect.TypeOf(o) - - if childType.Implements(ctxType) { - j++ - if j == i { - return o.(RuleContext) - } - } - } - return nil -} - -// Go lacks generics, so it's not possible for us to return the child with the correct type, but we do -// check for convertibility - -func (prc *BaseParserRuleContext) GetTypedRuleContext(ctxType reflect.Type, i int) RuleContext { - return prc.getChild(ctxType, i) -} - -func (prc *BaseParserRuleContext) GetTypedRuleContexts(ctxType reflect.Type) []RuleContext { - if prc.children == nil { - return make([]RuleContext, 0) - } - - contexts := make([]RuleContext, 0) - - for _, child := range prc.children { - childType := reflect.TypeOf(child) - - if childType.ConvertibleTo(ctxType) { - contexts = append(contexts, child.(RuleContext)) - } - } - return contexts -} - -func (prc *BaseParserRuleContext) GetChildCount() int { - if prc.children == nil { - return 0 - } - - return len(prc.children) -} - -func (prc *BaseParserRuleContext) GetSourceInterval() *Interval { - if prc.start == nil || prc.stop == nil { - return TreeInvalidInterval - } - - return NewInterval(prc.start.GetTokenIndex(), prc.stop.GetTokenIndex()) -} - -//need to manage circular dependencies, so export now - -// Print out a whole tree, not just a node, in LISP format -// (root child1 .. childN). Print just a node if b is a leaf. -// - -func (prc *BaseParserRuleContext) String(ruleNames []string, stop RuleContext) string { - - var p ParserRuleContext = prc - s := "[" - for p != nil && p != stop { - if ruleNames == nil { - if !p.IsEmpty() { - s += strconv.Itoa(p.GetInvokingState()) - } - } else { - ri := p.GetRuleIndex() - var ruleName string - if ri >= 0 && ri < len(ruleNames) { - ruleName = ruleNames[ri] - } else { - ruleName = strconv.Itoa(ri) - } - s += ruleName - } - if p.GetParent() != nil && (ruleNames != nil || !p.GetParent().(ParserRuleContext).IsEmpty()) { - s += " " - } - pi := p.GetParent() - if pi != nil { - p = pi.(ParserRuleContext) - } else { - p = nil - } - } - s += "]" - return s -} - -var ParserRuleContextEmpty = NewBaseParserRuleContext(nil, -1) - -type InterpreterRuleContext interface { - ParserRuleContext -} - -type BaseInterpreterRuleContext struct { - *BaseParserRuleContext -} - -func NewBaseInterpreterRuleContext(parent BaseInterpreterRuleContext, invokingStateNumber, ruleIndex int) *BaseInterpreterRuleContext { - - prc := new(BaseInterpreterRuleContext) - - prc.BaseParserRuleContext = NewBaseParserRuleContext(parent, invokingStateNumber) - - prc.RuleIndex = ruleIndex - - return prc -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "reflect" + "strconv" +) + +type ParserRuleContext interface { + RuleContext + + SetException(RecognitionException) + + AddTokenNode(token Token) *TerminalNodeImpl + AddErrorNode(badToken Token) *ErrorNodeImpl + + EnterRule(listener ParseTreeListener) + ExitRule(listener ParseTreeListener) + + SetStart(Token) + GetStart() Token + + SetStop(Token) + GetStop() Token + + AddChild(child RuleContext) RuleContext + RemoveLastChild() +} + +type BaseParserRuleContext struct { + *BaseRuleContext + + start, stop Token + exception RecognitionException + children []Tree +} + +func NewBaseParserRuleContext(parent ParserRuleContext, invokingStateNumber int) *BaseParserRuleContext { + prc := new(BaseParserRuleContext) + + prc.BaseRuleContext = NewBaseRuleContext(parent, invokingStateNumber) + + prc.RuleIndex = -1 + // * If we are debugging or building a parse tree for a Visitor, + // we need to track all of the tokens and rule invocations associated + // with prc rule's context. This is empty for parsing w/o tree constr. + // operation because we don't the need to track the details about + // how we parse prc rule. + // / + prc.children = nil + prc.start = nil + prc.stop = nil + // The exception that forced prc rule to return. If the rule successfully + // completed, prc is {@code nil}. + prc.exception = nil + + return prc +} + +func (prc *BaseParserRuleContext) SetException(e RecognitionException) { + prc.exception = e +} + +func (prc *BaseParserRuleContext) GetChildren() []Tree { + return prc.children +} + +func (prc *BaseParserRuleContext) CopyFrom(ctx *BaseParserRuleContext) { + // from RuleContext + prc.parentCtx = ctx.parentCtx + prc.invokingState = ctx.invokingState + prc.children = nil + prc.start = ctx.start + prc.stop = ctx.stop +} + +func (prc *BaseParserRuleContext) GetText() string { + if prc.GetChildCount() == 0 { + return "" + } + + var s string + for _, child := range prc.children { + s += child.(ParseTree).GetText() + } + + return s +} + +// Double dispatch methods for listeners +func (prc *BaseParserRuleContext) EnterRule(listener ParseTreeListener) { +} + +func (prc *BaseParserRuleContext) ExitRule(listener ParseTreeListener) { +} + +// * Does not set parent link other add methods do that/// +func (prc *BaseParserRuleContext) addTerminalNodeChild(child TerminalNode) TerminalNode { + if prc.children == nil { + prc.children = make([]Tree, 0) + } + if child == nil { + panic("Child may not be null") + } + prc.children = append(prc.children, child) + return child +} + +func (prc *BaseParserRuleContext) AddChild(child RuleContext) RuleContext { + if prc.children == nil { + prc.children = make([]Tree, 0) + } + if child == nil { + panic("Child may not be null") + } + prc.children = append(prc.children, child) + return child +} + +// * Used by EnterOuterAlt to toss out a RuleContext previously added as +// we entered a rule. If we have // label, we will need to remove +// generic ruleContext object. +// / +func (prc *BaseParserRuleContext) RemoveLastChild() { + if prc.children != nil && len(prc.children) > 0 { + prc.children = prc.children[0 : len(prc.children)-1] + } +} + +func (prc *BaseParserRuleContext) AddTokenNode(token Token) *TerminalNodeImpl { + + node := NewTerminalNodeImpl(token) + prc.addTerminalNodeChild(node) + node.parentCtx = prc + return node + +} + +func (prc *BaseParserRuleContext) AddErrorNode(badToken Token) *ErrorNodeImpl { + node := NewErrorNodeImpl(badToken) + prc.addTerminalNodeChild(node) + node.parentCtx = prc + return node +} + +func (prc *BaseParserRuleContext) GetChild(i int) Tree { + if prc.children != nil && len(prc.children) >= i { + return prc.children[i] + } + + return nil +} + +func (prc *BaseParserRuleContext) GetChildOfType(i int, childType reflect.Type) RuleContext { + if childType == nil { + return prc.GetChild(i).(RuleContext) + } + + for j := 0; j < len(prc.children); j++ { + child := prc.children[j] + if reflect.TypeOf(child) == childType { + if i == 0 { + return child.(RuleContext) + } + + i-- + } + } + + return nil +} + +func (prc *BaseParserRuleContext) ToStringTree(ruleNames []string, recog Recognizer) string { + return TreesStringTree(prc, ruleNames, recog) +} + +func (prc *BaseParserRuleContext) GetRuleContext() RuleContext { + return prc +} + +func (prc *BaseParserRuleContext) Accept(visitor ParseTreeVisitor) interface{} { + return visitor.VisitChildren(prc) +} + +func (prc *BaseParserRuleContext) SetStart(t Token) { + prc.start = t +} + +func (prc *BaseParserRuleContext) GetStart() Token { + return prc.start +} + +func (prc *BaseParserRuleContext) SetStop(t Token) { + prc.stop = t +} + +func (prc *BaseParserRuleContext) GetStop() Token { + return prc.stop +} + +func (prc *BaseParserRuleContext) GetToken(ttype int, i int) TerminalNode { + + for j := 0; j < len(prc.children); j++ { + child := prc.children[j] + if c2, ok := child.(TerminalNode); ok { + if c2.GetSymbol().GetTokenType() == ttype { + if i == 0 { + return c2 + } + + i-- + } + } + } + return nil +} + +func (prc *BaseParserRuleContext) GetTokens(ttype int) []TerminalNode { + if prc.children == nil { + return make([]TerminalNode, 0) + } + + tokens := make([]TerminalNode, 0) + + for j := 0; j < len(prc.children); j++ { + child := prc.children[j] + if tchild, ok := child.(TerminalNode); ok { + if tchild.GetSymbol().GetTokenType() == ttype { + tokens = append(tokens, tchild) + } + } + } + + return tokens +} + +func (prc *BaseParserRuleContext) GetPayload() interface{} { + return prc +} + +func (prc *BaseParserRuleContext) getChild(ctxType reflect.Type, i int) RuleContext { + if prc.children == nil || i < 0 || i >= len(prc.children) { + return nil + } + + j := -1 // what element have we found with ctxType? + for _, o := range prc.children { + + childType := reflect.TypeOf(o) + + if childType.Implements(ctxType) { + j++ + if j == i { + return o.(RuleContext) + } + } + } + return nil +} + +// Go lacks generics, so it's not possible for us to return the child with the correct type, but we do +// check for convertibility + +func (prc *BaseParserRuleContext) GetTypedRuleContext(ctxType reflect.Type, i int) RuleContext { + return prc.getChild(ctxType, i) +} + +func (prc *BaseParserRuleContext) GetTypedRuleContexts(ctxType reflect.Type) []RuleContext { + if prc.children == nil { + return make([]RuleContext, 0) + } + + contexts := make([]RuleContext, 0) + + for _, child := range prc.children { + childType := reflect.TypeOf(child) + + if childType.ConvertibleTo(ctxType) { + contexts = append(contexts, child.(RuleContext)) + } + } + return contexts +} + +func (prc *BaseParserRuleContext) GetChildCount() int { + if prc.children == nil { + return 0 + } + + return len(prc.children) +} + +func (prc *BaseParserRuleContext) GetSourceInterval() *Interval { + if prc.start == nil || prc.stop == nil { + return TreeInvalidInterval + } + + return NewInterval(prc.start.GetTokenIndex(), prc.stop.GetTokenIndex()) +} + +//need to manage circular dependencies, so export now + +// Print out a whole tree, not just a node, in LISP format +// (root child1 .. childN). Print just a node if b is a leaf. +// + +func (prc *BaseParserRuleContext) String(ruleNames []string, stop RuleContext) string { + + var p ParserRuleContext = prc + s := "[" + for p != nil && p != stop { + if ruleNames == nil { + if !p.IsEmpty() { + s += strconv.Itoa(p.GetInvokingState()) + } + } else { + ri := p.GetRuleIndex() + var ruleName string + if ri >= 0 && ri < len(ruleNames) { + ruleName = ruleNames[ri] + } else { + ruleName = strconv.Itoa(ri) + } + s += ruleName + } + if p.GetParent() != nil && (ruleNames != nil || !p.GetParent().(ParserRuleContext).IsEmpty()) { + s += " " + } + pi := p.GetParent() + if pi != nil { + p = pi.(ParserRuleContext) + } else { + p = nil + } + } + s += "]" + return s +} + +var ParserRuleContextEmpty = NewBaseParserRuleContext(nil, -1) + +type InterpreterRuleContext interface { + ParserRuleContext +} + +type BaseInterpreterRuleContext struct { + *BaseParserRuleContext +} + +func NewBaseInterpreterRuleContext(parent BaseInterpreterRuleContext, invokingStateNumber, ruleIndex int) *BaseInterpreterRuleContext { + + prc := new(BaseInterpreterRuleContext) + + prc.BaseParserRuleContext = NewBaseParserRuleContext(parent, invokingStateNumber) + + prc.RuleIndex = ruleIndex + + return prc +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/prediction_context.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/prediction_context.go index ba62af3610..d7ff7458a8 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/prediction_context.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/prediction_context.go @@ -1,806 +1,806 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "fmt" - "golang.org/x/exp/slices" - "strconv" -) - -// Represents {@code $} in local context prediction, which means wildcard. -// {@code//+x =//}. -// / -const ( - BasePredictionContextEmptyReturnState = 0x7FFFFFFF -) - -// Represents {@code $} in an array in full context mode, when {@code $} -// doesn't mean wildcard: {@code $ + x = [$,x]}. Here, -// {@code $} = {@link //EmptyReturnState}. -// / - -var ( - BasePredictionContextglobalNodeCount = 1 - BasePredictionContextid = BasePredictionContextglobalNodeCount -) - -type PredictionContext interface { - Hash() int - Equals(interface{}) bool - GetParent(int) PredictionContext - getReturnState(int) int - length() int - isEmpty() bool - hasEmptyPath() bool - String() string -} - -type BasePredictionContext struct { - cachedHash int -} - -func NewBasePredictionContext(cachedHash int) *BasePredictionContext { - pc := new(BasePredictionContext) - pc.cachedHash = cachedHash - - return pc -} - -func (b *BasePredictionContext) isEmpty() bool { - return false -} - -func calculateHash(parent PredictionContext, returnState int) int { - h := murmurInit(1) - h = murmurUpdate(h, parent.Hash()) - h = murmurUpdate(h, returnState) - return murmurFinish(h, 2) -} - -var _emptyPredictionContextHash int - -func init() { - _emptyPredictionContextHash = murmurInit(1) - _emptyPredictionContextHash = murmurFinish(_emptyPredictionContextHash, 0) -} - -func calculateEmptyHash() int { - return _emptyPredictionContextHash -} - -// Used to cache {@link BasePredictionContext} objects. Its used for the shared -// context cash associated with contexts in DFA states. This cache -// can be used for both lexers and parsers. - -type PredictionContextCache struct { - cache map[PredictionContext]PredictionContext -} - -func NewPredictionContextCache() *PredictionContextCache { - t := new(PredictionContextCache) - t.cache = make(map[PredictionContext]PredictionContext) - return t -} - -// Add a context to the cache and return it. If the context already exists, -// return that one instead and do not add a Newcontext to the cache. -// Protect shared cache from unsafe thread access. -func (p *PredictionContextCache) add(ctx PredictionContext) PredictionContext { - if ctx == BasePredictionContextEMPTY { - return BasePredictionContextEMPTY - } - existing := p.cache[ctx] - if existing != nil { - return existing - } - p.cache[ctx] = ctx - return ctx -} - -func (p *PredictionContextCache) Get(ctx PredictionContext) PredictionContext { - return p.cache[ctx] -} - -func (p *PredictionContextCache) length() int { - return len(p.cache) -} - -type SingletonPredictionContext interface { - PredictionContext -} - -type BaseSingletonPredictionContext struct { - *BasePredictionContext - - parentCtx PredictionContext - returnState int -} - -func NewBaseSingletonPredictionContext(parent PredictionContext, returnState int) *BaseSingletonPredictionContext { - var cachedHash int - if parent != nil { - cachedHash = calculateHash(parent, returnState) - } else { - cachedHash = calculateEmptyHash() - } - - s := new(BaseSingletonPredictionContext) - s.BasePredictionContext = NewBasePredictionContext(cachedHash) - - s.parentCtx = parent - s.returnState = returnState - - return s -} - -func SingletonBasePredictionContextCreate(parent PredictionContext, returnState int) PredictionContext { - if returnState == BasePredictionContextEmptyReturnState && parent == nil { - // someone can pass in the bits of an array ctx that mean $ - return BasePredictionContextEMPTY - } - - return NewBaseSingletonPredictionContext(parent, returnState) -} - -func (b *BaseSingletonPredictionContext) length() int { - return 1 -} - -func (b *BaseSingletonPredictionContext) GetParent(index int) PredictionContext { - return b.parentCtx -} - -func (b *BaseSingletonPredictionContext) getReturnState(index int) int { - return b.returnState -} - -func (b *BaseSingletonPredictionContext) hasEmptyPath() bool { - return b.returnState == BasePredictionContextEmptyReturnState -} - -func (b *BaseSingletonPredictionContext) Hash() int { - return b.cachedHash -} - -func (b *BaseSingletonPredictionContext) Equals(other interface{}) bool { - if b == other { - return true - } - if _, ok := other.(*BaseSingletonPredictionContext); !ok { - return false - } - - otherP := other.(*BaseSingletonPredictionContext) - - if b.returnState != otherP.getReturnState(0) { - return false - } - if b.parentCtx == nil { - return otherP.parentCtx == nil - } - - return b.parentCtx.Equals(otherP.parentCtx) -} - -func (b *BaseSingletonPredictionContext) String() string { - var up string - - if b.parentCtx == nil { - up = "" - } else { - up = b.parentCtx.String() - } - - if len(up) == 0 { - if b.returnState == BasePredictionContextEmptyReturnState { - return "$" - } - - return strconv.Itoa(b.returnState) - } - - return strconv.Itoa(b.returnState) + " " + up -} - -var BasePredictionContextEMPTY = NewEmptyPredictionContext() - -type EmptyPredictionContext struct { - *BaseSingletonPredictionContext -} - -func NewEmptyPredictionContext() *EmptyPredictionContext { - - p := new(EmptyPredictionContext) - - p.BaseSingletonPredictionContext = NewBaseSingletonPredictionContext(nil, BasePredictionContextEmptyReturnState) - p.cachedHash = calculateEmptyHash() - return p -} - -func (e *EmptyPredictionContext) isEmpty() bool { - return true -} - -func (e *EmptyPredictionContext) GetParent(index int) PredictionContext { - return nil -} - -func (e *EmptyPredictionContext) getReturnState(index int) int { - return e.returnState -} - -func (e *EmptyPredictionContext) Hash() int { - return e.cachedHash -} - -func (e *EmptyPredictionContext) Equals(other interface{}) bool { - return e == other -} - -func (e *EmptyPredictionContext) String() string { - return "$" -} - -type ArrayPredictionContext struct { - *BasePredictionContext - - parents []PredictionContext - returnStates []int -} - -func NewArrayPredictionContext(parents []PredictionContext, returnStates []int) *ArrayPredictionContext { - // Parent can be nil only if full ctx mode and we make an array - // from {@link //EMPTY} and non-empty. We merge {@link //EMPTY} by using - // nil parent and - // returnState == {@link //EmptyReturnState}. - hash := murmurInit(1) - - for _, parent := range parents { - hash = murmurUpdate(hash, parent.Hash()) - } - - for _, returnState := range returnStates { - hash = murmurUpdate(hash, returnState) - } - - hash = murmurFinish(hash, len(parents)<<1) - - c := new(ArrayPredictionContext) - c.BasePredictionContext = NewBasePredictionContext(hash) - - c.parents = parents - c.returnStates = returnStates - - return c -} - -func (a *ArrayPredictionContext) GetReturnStates() []int { - return a.returnStates -} - -func (a *ArrayPredictionContext) hasEmptyPath() bool { - return a.getReturnState(a.length()-1) == BasePredictionContextEmptyReturnState -} - -func (a *ArrayPredictionContext) isEmpty() bool { - // since EmptyReturnState can only appear in the last position, we - // don't need to verify that size==1 - return a.returnStates[0] == BasePredictionContextEmptyReturnState -} - -func (a *ArrayPredictionContext) length() int { - return len(a.returnStates) -} - -func (a *ArrayPredictionContext) GetParent(index int) PredictionContext { - return a.parents[index] -} - -func (a *ArrayPredictionContext) getReturnState(index int) int { - return a.returnStates[index] -} - -// Equals is the default comparison function for ArrayPredictionContext when no specialized -// implementation is needed for a collection -func (a *ArrayPredictionContext) Equals(o interface{}) bool { - if a == o { - return true - } - other, ok := o.(*ArrayPredictionContext) - if !ok { - return false - } - if a.cachedHash != other.Hash() { - return false // can't be same if hash is different - } - - // Must compare the actual array elements and not just the array address - // - return slices.Equal(a.returnStates, other.returnStates) && - slices.EqualFunc(a.parents, other.parents, func(x, y PredictionContext) bool { - return x.Equals(y) - }) -} - -// Hash is the default hash function for ArrayPredictionContext when no specialized -// implementation is needed for a collection -func (a *ArrayPredictionContext) Hash() int { - return a.BasePredictionContext.cachedHash -} - -func (a *ArrayPredictionContext) String() string { - if a.isEmpty() { - return "[]" - } - - s := "[" - for i := 0; i < len(a.returnStates); i++ { - if i > 0 { - s = s + ", " - } - if a.returnStates[i] == BasePredictionContextEmptyReturnState { - s = s + "$" - continue - } - s = s + strconv.Itoa(a.returnStates[i]) - if a.parents[i] != nil { - s = s + " " + a.parents[i].String() - } else { - s = s + "nil" - } - } - - return s + "]" -} - -// Convert a {@link RuleContext} tree to a {@link BasePredictionContext} graph. -// Return {@link //EMPTY} if {@code outerContext} is empty or nil. -// / -func predictionContextFromRuleContext(a *ATN, outerContext RuleContext) PredictionContext { - if outerContext == nil { - outerContext = ParserRuleContextEmpty - } - // if we are in RuleContext of start rule, s, then BasePredictionContext - // is EMPTY. Nobody called us. (if we are empty, return empty) - if outerContext.GetParent() == nil || outerContext == ParserRuleContextEmpty { - return BasePredictionContextEMPTY - } - // If we have a parent, convert it to a BasePredictionContext graph - parent := predictionContextFromRuleContext(a, outerContext.GetParent().(RuleContext)) - state := a.states[outerContext.GetInvokingState()] - transition := state.GetTransitions()[0] - - return SingletonBasePredictionContextCreate(parent, transition.(*RuleTransition).followState.GetStateNumber()) -} - -func merge(a, b PredictionContext, rootIsWildcard bool, mergeCache *DoubleDict) PredictionContext { - - // Share same graph if both same - // - if a == b || a.Equals(b) { - return a - } - - // In Java, EmptyPredictionContext inherits from SingletonPredictionContext, and so the test - // in java for SingletonPredictionContext will succeed and a new ArrayPredictionContext will be created - // from it. - // In go, EmptyPredictionContext does not equate to SingletonPredictionContext and so that conversion - // will fail. We need to test for both Empty and Singleton and create an ArrayPredictionContext from - // either of them. - - ac, ok1 := a.(*BaseSingletonPredictionContext) - bc, ok2 := b.(*BaseSingletonPredictionContext) - - if ok1 && ok2 { - return mergeSingletons(ac, bc, rootIsWildcard, mergeCache) - } - // At least one of a or b is array - // If one is $ and rootIsWildcard, return $ as// wildcard - if rootIsWildcard { - if _, ok := a.(*EmptyPredictionContext); ok { - return a - } - if _, ok := b.(*EmptyPredictionContext); ok { - return b - } - } - - // Convert Singleton or Empty so both are arrays to normalize - We should not use the existing parameters - // here. - // - // TODO: I think that maybe the Prediction Context structs should be redone as there is a chance we will see this mess again - maybe redo the logic here - - var arp, arb *ArrayPredictionContext - var ok bool - if arp, ok = a.(*ArrayPredictionContext); ok { - } else if _, ok = a.(*BaseSingletonPredictionContext); ok { - arp = NewArrayPredictionContext([]PredictionContext{a.GetParent(0)}, []int{a.getReturnState(0)}) - } else if _, ok = a.(*EmptyPredictionContext); ok { - arp = NewArrayPredictionContext([]PredictionContext{}, []int{}) - } - - if arb, ok = b.(*ArrayPredictionContext); ok { - } else if _, ok = b.(*BaseSingletonPredictionContext); ok { - arb = NewArrayPredictionContext([]PredictionContext{b.GetParent(0)}, []int{b.getReturnState(0)}) - } else if _, ok = b.(*EmptyPredictionContext); ok { - arb = NewArrayPredictionContext([]PredictionContext{}, []int{}) - } - - // Both arp and arb - return mergeArrays(arp, arb, rootIsWildcard, mergeCache) -} - -// Merge two {@link SingletonBasePredictionContext} instances. -// -//Stack tops equal, parents merge is same return left graph.
-//
Same stack top, parents differ merge parents giving array node, then
-// remainders of those graphs. A Newroot node is created to point to the
-// merged parents.
-//
Different stack tops pointing to same parent. Make array node for the
-// root where both element in the root point to the same (original)
-// parent.
-//
Different stack tops pointing to different parents. Make array node for
-// the root where each element points to the corresponding original
-// parent.
-//
Local-Context Merges
-// -//These local-context merge operations are used when {@code rootIsWildcard} -// is true.
-// -//{@link //EMPTY} is superset of any graph return {@link //EMPTY}.
-//
{@link //EMPTY} and anything is {@code //EMPTY}, so merged parent is
-// {@code //EMPTY} return left graph.
-//
Special case of last merge if local context.
-//
Full-Context Merges
-// -//These full-context merge operations are used when {@code rootIsWildcard} -// is false.
-// -// -// -//Must keep all contexts {@link //EMPTY} in array is a special value (and
-// nil parent).
-//
Different tops, different parents.
-//
Shared top, same parents.
-//
Shared top, different parents.
-//
Shared top, all shared parents.
-//
Equal tops, merge parents and reduce top to
-// {@link SingletonBasePredictionContext}.
-//
Stack tops equal, parents merge is same return left graph.
+//
Same stack top, parents differ merge parents giving array node, then
+// remainders of those graphs. A Newroot node is created to point to the
+// merged parents.
+//
Different stack tops pointing to same parent. Make array node for the
+// root where both element in the root point to the same (original)
+// parent.
+//
Different stack tops pointing to different parents. Make array node for
+// the root where each element points to the corresponding original
+// parent.
+//
Local-Context Merges
+// +//These local-context merge operations are used when {@code rootIsWildcard} +// is true.
+// +//{@link //EMPTY} is superset of any graph return {@link //EMPTY}.
+//
{@link //EMPTY} and anything is {@code //EMPTY}, so merged parent is
+// {@code //EMPTY} return left graph.
+//
Special case of last merge if local context.
+//
Full-Context Merges
+// +//These full-context merge operations are used when {@code rootIsWildcard} +// is false.
+// +// +// +//Must keep all contexts {@link //EMPTY} in array is a special value (and
+// nil parent).
+//
Different tops, different parents.
+//
Shared top, same parents.
+//
Shared top, different parents.
+//
Shared top, all shared parents.
+//
Equal tops, merge parents and reduce top to
+// {@link SingletonBasePredictionContext}.
+//
- // When using this prediction mode, the parser will either return a correct - // parse tree (i.e. the same parse tree that would be returned with the - // {@link //LL} prediction mode), or it will Report a syntax error. If a - // syntax error is encountered when using the {@link //SLL} prediction mode, - // it may be due to either an actual syntax error in the input or indicate - // that the particular combination of grammar and input requires the more - // powerful {@link //LL} prediction abilities to complete successfully.
- // - //- // This prediction mode does not provide any guarantees for prediction - // behavior for syntactically-incorrect inputs.
- // - PredictionModeSLL = 0 - // - // The LL(*) prediction mode. This prediction mode allows the current parser - // context to be used for resolving SLL conflicts that occur during - // prediction. This is the fastest prediction mode that guarantees correct - // parse results for all combinations of grammars with syntactically correct - // inputs. - // - //- // When using this prediction mode, the parser will make correct decisions - // for all syntactically-correct grammar and input combinations. However, in - // cases where the grammar is truly ambiguous this prediction mode might not - // Report a precise answer for exactly which alternatives are - // ambiguous.
- // - //- // This prediction mode does not provide any guarantees for prediction - // behavior for syntactically-incorrect inputs.
- // - PredictionModeLL = 1 - // - // The LL(*) prediction mode with exact ambiguity detection. In addition to - // the correctness guarantees provided by the {@link //LL} prediction mode, - // this prediction mode instructs the prediction algorithm to determine the - // complete and exact set of ambiguous alternatives for every ambiguous - // decision encountered while parsing. - // - //- // This prediction mode may be used for diagnosing ambiguities during - // grammar development. Due to the performance overhead of calculating sets - // of ambiguous alternatives, this prediction mode should be avoided when - // the exact results are not necessary.
- // - //- // This prediction mode does not provide any guarantees for prediction - // behavior for syntactically-incorrect inputs.
- // - PredictionModeLLExactAmbigDetection = 2 -) - -// Computes the SLL prediction termination condition. -// -//-// This method computes the SLL prediction termination condition for both of -// the following cases.
-// -//-
-//
- The usual SLL+LL fallback upon SLL conflict -//
- Pure SLL without LL fallback -//
COMBINED SLL+LL PARSING
-// -//When LL-fallback is enabled upon SLL conflict, correct predictions are -// ensured regardless of how the termination condition is computed by this -// method. Due to the substantially higher cost of LL prediction, the -// prediction should only fall back to LL when the additional lookahead -// cannot lead to a unique SLL prediction.
-// -//Assuming combined SLL+LL parsing, an SLL configuration set with only -// conflicting subsets should fall back to full LL, even if the -// configuration sets don't resolve to the same alternative (e.g. -// {@code {1,2}} and {@code {3,4}}. If there is at least one non-conflicting -// configuration, SLL could continue with the hopes that more lookahead will -// resolve via one of those non-conflicting configurations.
-// -//Here's the prediction termination rule them: SLL (for SLL+LL parsing) -// stops when it sees only conflicting configuration subsets. In contrast, -// full LL keeps going when there is uncertainty.
-// -//HEURISTIC
-// -//As a heuristic, we stop prediction when we see any conflicting subset -// unless we see a state that only has one alternative associated with it. -// The single-alt-state thing lets prediction continue upon rules like -// (otherwise, it would admit defeat too soon):
-// -//{@code [12|1|[], 6|2|[], 12|2|[]]. s : (ID | ID ID?) ” }
-// -//When the ATN simulation reaches the state before {@code ”}, it has a -// DFA state that looks like: {@code [12|1|[], 6|2|[], 12|2|[]]}. Naturally -// {@code 12|1|[]} and {@code 12|2|[]} conflict, but we cannot stop -// processing this node because alternative to has another way to continue, -// via {@code [6|2|[]]}.
-// -//It also let's us continue for this rule:
-// -//{@code [1|1|[], 1|2|[], 8|3|[]] a : A | A | A B }
-// -//After Matching input A, we reach the stop state for rule A, state 1. -// State 8 is the state right before B. Clearly alternatives 1 and 2 -// conflict and no amount of further lookahead will separate the two. -// However, alternative 3 will be able to continue and so we do not stop -// working on this state. In the previous example, we're concerned with -// states associated with the conflicting alternatives. Here alt 3 is not -// associated with the conflicting configs, but since we can continue -// looking for input reasonably, don't declare the state done.
-// -//PURE SLL PARSING
-// -//To handle pure SLL parsing, all we have to do is make sure that we -// combine stack contexts for configurations that differ only by semantic -// predicate. From there, we can do the usual SLL termination heuristic.
-// -//PREDICATES IN SLL+LL PARSING
-// -//SLL decisions don't evaluate predicates until after they reach DFA stop -// states because they need to create the DFA cache that works in all -// semantic situations. In contrast, full LL evaluates predicates collected -// during start state computation so it can ignore predicates thereafter. -// This means that SLL termination detection can totally ignore semantic -// predicates.
-// -//Implementation-wise, {@link ATNConfigSet} combines stack contexts but not -// semantic predicate contexts so we might see two configurations like the -// following.
-// -//{@code (s, 1, x, {}), (s, 1, x', {p})}
-// -//Before testing these configurations against others, we have to merge -// {@code x} and {@code x'} (without modifying the existing configurations). -// For example, we test {@code (x+x')==x”} when looking for conflicts in -// the following configurations.
-// -//{@code (s, 1, x, {}), (s, 1, x', {p}), (s, 2, x”, {})}
-// -//If the configuration set has predicates (as indicated by -// {@link ATNConfigSet//hasSemanticContext}), this algorithm makes a copy of -// the configurations to strip out all of the predicates so that a standard -// {@link ATNConfigSet} will merge everything ignoring predicates.
-func PredictionModehasSLLConflictTerminatingPrediction(mode int, configs ATNConfigSet) bool { - // Configs in rule stop states indicate reaching the end of the decision - // rule (local context) or end of start rule (full context). If all - // configs meet this condition, then none of the configurations is able - // to Match additional input so we terminate prediction. - // - if PredictionModeallConfigsInRuleStopStates(configs) { - return true - } - // pure SLL mode parsing - if mode == PredictionModeSLL { - // Don't bother with combining configs from different semantic - // contexts if we can fail over to full LL costs more time - // since we'll often fail over anyway. - if configs.HasSemanticContext() { - // dup configs, tossing out semantic predicates - dup := NewBaseATNConfigSet(false) - for _, c := range configs.GetItems() { - - // NewBaseATNConfig({semanticContext:}, c) - c = NewBaseATNConfig2(c, SemanticContextNone) - dup.Add(c, nil) - } - configs = dup - } - // now we have combined contexts for configs with dissimilar preds - } - // pure SLL or combined SLL+LL mode parsing - altsets := PredictionModegetConflictingAltSubsets(configs) - return PredictionModehasConflictingAltSet(altsets) && !PredictionModehasStateAssociatedWithOneAlt(configs) -} - -// Checks if any configuration in {@code configs} is in a -// {@link RuleStopState}. Configurations meeting this condition have reached -// the end of the decision rule (local context) or end of start rule (full -// context). -// -// @param configs the configuration set to test -// @return {@code true} if any configuration in {@code configs} is in a -// {@link RuleStopState}, otherwise {@code false} -func PredictionModehasConfigInRuleStopState(configs ATNConfigSet) bool { - for _, c := range configs.GetItems() { - if _, ok := c.GetState().(*RuleStopState); ok { - return true - } - } - return false -} - -// Checks if all configurations in {@code configs} are in a -// {@link RuleStopState}. Configurations meeting this condition have reached -// the end of the decision rule (local context) or end of start rule (full -// context). -// -// @param configs the configuration set to test -// @return {@code true} if all configurations in {@code configs} are in a -// {@link RuleStopState}, otherwise {@code false} -func PredictionModeallConfigsInRuleStopStates(configs ATNConfigSet) bool { - - for _, c := range configs.GetItems() { - if _, ok := c.GetState().(*RuleStopState); !ok { - return false - } - } - return true -} - -// Full LL prediction termination. -// -//Can we stop looking ahead during ATN simulation or is there some -// uncertainty as to which alternative we will ultimately pick, after -// consuming more input? Even if there are partial conflicts, we might know -// that everything is going to resolve to the same minimum alternative. That -// means we can stop since no more lookahead will change that fact. On the -// other hand, there might be multiple conflicts that resolve to different -// minimums. That means we need more look ahead to decide which of those -// alternatives we should predict.
-// -//The basic idea is to split the set of configurations {@code C}, into -// conflicting subsets {@code (s, _, ctx, _)} and singleton subsets with -// non-conflicting configurations. Two configurations conflict if they have -// identical {@link ATNConfig//state} and {@link ATNConfig//context} values -// but different {@link ATNConfig//alt} value, e.g. {@code (s, i, ctx, _)} -// and {@code (s, j, ctx, _)} for {@code i!=j}.
-// -//Reduce these configuration subsets to the set of possible alternatives. -// You can compute the alternative subsets in one pass as follows:
-// -//{@code A_s,ctx = {i | (s, i, ctx, _)}} for each configuration in -// {@code C} holding {@code s} and {@code ctx} fixed.
-// -//Or in pseudo-code, for each configuration {@code c} in {@code C}:
-// -//
-// map[c] U= c.{@link ATNConfig//alt alt} // map hash/equals uses s and x, not
-// alt and not pred
-//
-//
-// The values in {@code map} are the set of {@code A_s,ctx} sets.
-// -//If {@code |A_s,ctx|=1} then there is no conflict associated with -// {@code s} and {@code ctx}.
-// -//Reduce the subsets to singletons by choosing a minimum of each subset. If -// the union of these alternative subsets is a singleton, then no amount of -// more lookahead will help us. We will always pick that alternative. If, -// however, there is more than one alternative, then we are uncertain which -// alternative to predict and must continue looking for resolution. We may -// or may not discover an ambiguity in the future, even if there are no -// conflicting subsets this round.
-// -//The biggest sin is to terminate early because it means we've made a -// decision but were uncertain as to the eventual outcome. We haven't used -// enough lookahead. On the other hand, announcing a conflict too late is no -// big deal you will still have the conflict. It's just inefficient. It -// might even look until the end of file.
-// -//No special consideration for semantic predicates is required because -// predicates are evaluated on-the-fly for full LL prediction, ensuring that -// no configuration contains a semantic context during the termination -// check.
-// -//CONFLICTING CONFIGS
-// -//Two configurations {@code (s, i, x)} and {@code (s, j, x')}, conflict -// when {@code i!=j} but {@code x=x'}. Because we merge all -// {@code (s, i, _)} configurations together, that means that there are at -// most {@code n} configurations associated with state {@code s} for -// {@code n} possible alternatives in the decision. The merged stacks -// complicate the comparison of configuration contexts {@code x} and -// {@code x'}. Sam checks to see if one is a subset of the other by calling -// merge and checking to see if the merged result is either {@code x} or -// {@code x'}. If the {@code x} associated with lowest alternative {@code i} -// is the superset, then {@code i} is the only possible prediction since the -// others resolve to {@code min(i)} as well. However, if {@code x} is -// associated with {@code j>i} then at least one stack configuration for -// {@code j} is not in conflict with alternative {@code i}. The algorithm -// should keep going, looking for more lookahead due to the uncertainty.
-// -//For simplicity, I'm doing a equality check between {@code x} and -// {@code x'} that lets the algorithm continue to consume lookahead longer -// than necessary. The reason I like the equality is of course the -// simplicity but also because that is the test you need to detect the -// alternatives that are actually in conflict.
-// -//CONTINUE/STOP RULE
-// -//Continue if union of resolved alternative sets from non-conflicting and -// conflicting alternative subsets has more than one alternative. We are -// uncertain about which alternative to predict.
-// -//The complete set of alternatives, {@code [i for (_,i,_)]}, tells us which -// alternatives are still in the running for the amount of input we've -// consumed at this point. The conflicting sets let us to strip away -// configurations that won't lead to more states because we resolve -// conflicts to the configuration with a minimum alternate for the -// conflicting set.
-// -//CASES
-// -//-
-//
-//
- no conflicts and more than 1 alternative in set => continue -// -//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s, 3, z)}, -// {@code (s', 1, y)}, {@code (s', 2, y)} yields non-conflicting set -// {@code {3}} U conflicting sets {@code min({1,2})} U {@code min({1,2})} = -// {@code {1,3}} => continue -// -// -//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 1, y)}, -// {@code (s', 2, y)}, {@code (s”, 1, z)} yields non-conflicting set -// {@code {1}} U conflicting sets {@code min({1,2})} U {@code min({1,2})} = -// {@code {1}} => stop and predict 1 -// -//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 1, y)}, -// {@code (s', 2, y)} yields conflicting, reduced sets {@code {1}} U -// {@code {1}} = {@code {1}} => stop and predict 1, can announce -// ambiguity {@code {1,2}} -// -//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 2, y)}, -// {@code (s', 3, y)} yields conflicting, reduced sets {@code {1}} U -// {@code {2}} = {@code {1,2}} => continue -// -//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 3, y)}, -// {@code (s', 4, y)} yields conflicting, reduced sets {@code {1}} U -// {@code {3}} = {@code {1,3}} => continue -// -//
EXACT AMBIGUITY DETECTION
-// -//If all states Report the same conflicting set of alternatives, then we -// know we have the exact ambiguity set.
-// -//|A_i|>1 and
-// A_i = A_j for all i, j.
In other words, we continue examining lookahead until all {@code A_i} -// have more than one alternative and all {@code A_i} are the same. If -// {@code A={{1,2}, {1,3}}}, then regular LL prediction would terminate -// because the resolved set is {@code {1}}. To determine what the real -// ambiguity is, we have to know whether the ambiguity is between one and -// two or one and three so we keep going. We can only stop prediction when -// we need exact ambiguity detection when the sets look like -// {@code A={{1,2}}} or {@code {{1,2},{1,2}}}, etc...
-func PredictionModeresolvesToJustOneViableAlt(altsets []*BitSet) int { - return PredictionModegetSingleViableAlt(altsets) -} - -// Determines if every alternative subset in {@code altsets} contains more -// than one alternative. -// -// @param altsets a collection of alternative subsets -// @return {@code true} if every {@link BitSet} in {@code altsets} has -// {@link BitSet//cardinality cardinality} > 1, otherwise {@code false} -func PredictionModeallSubsetsConflict(altsets []*BitSet) bool { - return !PredictionModehasNonConflictingAltSet(altsets) -} - -// Determines if any single alternative subset in {@code altsets} contains -// exactly one alternative. -// -// @param altsets a collection of alternative subsets -// @return {@code true} if {@code altsets} contains a {@link BitSet} with -// {@link BitSet//cardinality cardinality} 1, otherwise {@code false} -func PredictionModehasNonConflictingAltSet(altsets []*BitSet) bool { - for i := 0; i < len(altsets); i++ { - alts := altsets[i] - if alts.length() == 1 { - return true - } - } - return false -} - -// Determines if any single alternative subset in {@code altsets} contains -// more than one alternative. -// -// @param altsets a collection of alternative subsets -// @return {@code true} if {@code altsets} contains a {@link BitSet} with -// {@link BitSet//cardinality cardinality} > 1, otherwise {@code false} -func PredictionModehasConflictingAltSet(altsets []*BitSet) bool { - for i := 0; i < len(altsets); i++ { - alts := altsets[i] - if alts.length() > 1 { - return true - } - } - return false -} - -// Determines if every alternative subset in {@code altsets} is equivalent. -// -// @param altsets a collection of alternative subsets -// @return {@code true} if every member of {@code altsets} is equal to the -// others, otherwise {@code false} -func PredictionModeallSubsetsEqual(altsets []*BitSet) bool { - var first *BitSet - - for i := 0; i < len(altsets); i++ { - alts := altsets[i] - if first == nil { - first = alts - } else if alts != first { - return false - } - } - - return true -} - -// Returns the unique alternative predicted by all alternative subsets in -// {@code altsets}. If no such alternative exists, this method returns -// {@link ATN//INVALID_ALT_NUMBER}. -// -// @param altsets a collection of alternative subsets -func PredictionModegetUniqueAlt(altsets []*BitSet) int { - all := PredictionModeGetAlts(altsets) - if all.length() == 1 { - return all.minValue() - } - - return ATNInvalidAltNumber -} - -// Gets the complete set of represented alternatives for a collection of -// alternative subsets. This method returns the union of each {@link BitSet} -// in {@code altsets}. -// -// @param altsets a collection of alternative subsets -// @return the set of represented alternatives in {@code altsets} -func PredictionModeGetAlts(altsets []*BitSet) *BitSet { - all := NewBitSet() - for _, alts := range altsets { - all.or(alts) - } - return all -} - -// PredictionModegetConflictingAltSubsets gets the conflicting alt subsets from a configuration set. -// For each configuration {@code c} in {@code configs}: -// -//
-// map[c] U= c.{@link ATNConfig//alt alt} // map hash/equals uses s and x, not
-// alt and not pred
-//
-func PredictionModegetConflictingAltSubsets(configs ATNConfigSet) []*BitSet {
- configToAlts := NewJMap[ATNConfig, *BitSet, *ATNAltConfigComparator[ATNConfig]](atnAltCfgEqInst)
-
- for _, c := range configs.GetItems() {
-
- alts, ok := configToAlts.Get(c)
- if !ok {
- alts = NewBitSet()
- configToAlts.Put(c, alts)
- }
- alts.add(c.GetAlt())
- }
-
- return configToAlts.Values()
-}
-
-// PredictionModeGetStateToAltMap gets a map from state to alt subset from a configuration set. For each
-// configuration {@code c} in {@code configs}:
-//
-//
-// map[c.{@link ATNConfig//state state}] U= c.{@link ATNConfig//alt alt}
-//
-func PredictionModeGetStateToAltMap(configs ATNConfigSet) *AltDict {
- m := NewAltDict()
-
- for _, c := range configs.GetItems() {
- alts := m.Get(c.GetState().String())
- if alts == nil {
- alts = NewBitSet()
- m.put(c.GetState().String(), alts)
- }
- alts.(*BitSet).add(c.GetAlt())
- }
- return m
-}
-
-func PredictionModehasStateAssociatedWithOneAlt(configs ATNConfigSet) bool {
- values := PredictionModeGetStateToAltMap(configs).values()
- for i := 0; i < len(values); i++ {
- if values[i].(*BitSet).length() == 1 {
- return true
- }
- }
- return false
-}
-
-func PredictionModegetSingleViableAlt(altsets []*BitSet) int {
- result := ATNInvalidAltNumber
-
- for i := 0; i < len(altsets); i++ {
- alts := altsets[i]
- minAlt := alts.minValue()
- if result == ATNInvalidAltNumber {
- result = minAlt
- } else if result != minAlt { // more than 1 viable alt
- return ATNInvalidAltNumber
- }
- }
- return result
-}
+// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved.
+// Use of this file is governed by the BSD 3-clause license that
+// can be found in the LICENSE.txt file in the project root.
+
+package antlr
+
+// This enumeration defines the prediction modes available in ANTLR 4 along with
+// utility methods for analyzing configuration sets for conflicts and/or
+// ambiguities.
+
+const (
+ //
+ // The SLL(*) prediction mode. This prediction mode ignores the current
+ // parser context when making predictions. This is the fastest prediction
+ // mode, and provides correct results for many grammars. This prediction
+ // mode is more powerful than the prediction mode provided by ANTLR 3, but
+ // may result in syntax errors for grammar and input combinations which are
+ // not SLL.
+ //
+ // + // When using this prediction mode, the parser will either return a correct + // parse tree (i.e. the same parse tree that would be returned with the + // {@link //LL} prediction mode), or it will Report a syntax error. If a + // syntax error is encountered when using the {@link //SLL} prediction mode, + // it may be due to either an actual syntax error in the input or indicate + // that the particular combination of grammar and input requires the more + // powerful {@link //LL} prediction abilities to complete successfully.
+ // + //+ // This prediction mode does not provide any guarantees for prediction + // behavior for syntactically-incorrect inputs.
+ // + PredictionModeSLL = 0 + // + // The LL(*) prediction mode. This prediction mode allows the current parser + // context to be used for resolving SLL conflicts that occur during + // prediction. This is the fastest prediction mode that guarantees correct + // parse results for all combinations of grammars with syntactically correct + // inputs. + // + //+ // When using this prediction mode, the parser will make correct decisions + // for all syntactically-correct grammar and input combinations. However, in + // cases where the grammar is truly ambiguous this prediction mode might not + // Report a precise answer for exactly which alternatives are + // ambiguous.
+ // + //+ // This prediction mode does not provide any guarantees for prediction + // behavior for syntactically-incorrect inputs.
+ // + PredictionModeLL = 1 + // + // The LL(*) prediction mode with exact ambiguity detection. In addition to + // the correctness guarantees provided by the {@link //LL} prediction mode, + // this prediction mode instructs the prediction algorithm to determine the + // complete and exact set of ambiguous alternatives for every ambiguous + // decision encountered while parsing. + // + //+ // This prediction mode may be used for diagnosing ambiguities during + // grammar development. Due to the performance overhead of calculating sets + // of ambiguous alternatives, this prediction mode should be avoided when + // the exact results are not necessary.
+ // + //+ // This prediction mode does not provide any guarantees for prediction + // behavior for syntactically-incorrect inputs.
+ // + PredictionModeLLExactAmbigDetection = 2 +) + +// Computes the SLL prediction termination condition. +// +//+// This method computes the SLL prediction termination condition for both of +// the following cases.
+// +//-
+//
- The usual SLL+LL fallback upon SLL conflict +//
- Pure SLL without LL fallback +//
COMBINED SLL+LL PARSING
+// +//When LL-fallback is enabled upon SLL conflict, correct predictions are +// ensured regardless of how the termination condition is computed by this +// method. Due to the substantially higher cost of LL prediction, the +// prediction should only fall back to LL when the additional lookahead +// cannot lead to a unique SLL prediction.
+// +//Assuming combined SLL+LL parsing, an SLL configuration set with only +// conflicting subsets should fall back to full LL, even if the +// configuration sets don't resolve to the same alternative (e.g. +// {@code {1,2}} and {@code {3,4}}. If there is at least one non-conflicting +// configuration, SLL could continue with the hopes that more lookahead will +// resolve via one of those non-conflicting configurations.
+// +//Here's the prediction termination rule them: SLL (for SLL+LL parsing) +// stops when it sees only conflicting configuration subsets. In contrast, +// full LL keeps going when there is uncertainty.
+// +//HEURISTIC
+// +//As a heuristic, we stop prediction when we see any conflicting subset +// unless we see a state that only has one alternative associated with it. +// The single-alt-state thing lets prediction continue upon rules like +// (otherwise, it would admit defeat too soon):
+// +//{@code [12|1|[], 6|2|[], 12|2|[]]. s : (ID | ID ID?) ” }
+// +//When the ATN simulation reaches the state before {@code ”}, it has a +// DFA state that looks like: {@code [12|1|[], 6|2|[], 12|2|[]]}. Naturally +// {@code 12|1|[]} and {@code 12|2|[]} conflict, but we cannot stop +// processing this node because alternative to has another way to continue, +// via {@code [6|2|[]]}.
+// +//It also let's us continue for this rule:
+// +//{@code [1|1|[], 1|2|[], 8|3|[]] a : A | A | A B }
+// +//After Matching input A, we reach the stop state for rule A, state 1. +// State 8 is the state right before B. Clearly alternatives 1 and 2 +// conflict and no amount of further lookahead will separate the two. +// However, alternative 3 will be able to continue and so we do not stop +// working on this state. In the previous example, we're concerned with +// states associated with the conflicting alternatives. Here alt 3 is not +// associated with the conflicting configs, but since we can continue +// looking for input reasonably, don't declare the state done.
+// +//PURE SLL PARSING
+// +//To handle pure SLL parsing, all we have to do is make sure that we +// combine stack contexts for configurations that differ only by semantic +// predicate. From there, we can do the usual SLL termination heuristic.
+// +//PREDICATES IN SLL+LL PARSING
+// +//SLL decisions don't evaluate predicates until after they reach DFA stop +// states because they need to create the DFA cache that works in all +// semantic situations. In contrast, full LL evaluates predicates collected +// during start state computation so it can ignore predicates thereafter. +// This means that SLL termination detection can totally ignore semantic +// predicates.
+// +//Implementation-wise, {@link ATNConfigSet} combines stack contexts but not +// semantic predicate contexts so we might see two configurations like the +// following.
+// +//{@code (s, 1, x, {}), (s, 1, x', {p})}
+// +//Before testing these configurations against others, we have to merge +// {@code x} and {@code x'} (without modifying the existing configurations). +// For example, we test {@code (x+x')==x”} when looking for conflicts in +// the following configurations.
+// +//{@code (s, 1, x, {}), (s, 1, x', {p}), (s, 2, x”, {})}
+// +//If the configuration set has predicates (as indicated by +// {@link ATNConfigSet//hasSemanticContext}), this algorithm makes a copy of +// the configurations to strip out all of the predicates so that a standard +// {@link ATNConfigSet} will merge everything ignoring predicates.
+func PredictionModehasSLLConflictTerminatingPrediction(mode int, configs ATNConfigSet) bool { + // Configs in rule stop states indicate reaching the end of the decision + // rule (local context) or end of start rule (full context). If all + // configs meet this condition, then none of the configurations is able + // to Match additional input so we terminate prediction. + // + if PredictionModeallConfigsInRuleStopStates(configs) { + return true + } + // pure SLL mode parsing + if mode == PredictionModeSLL { + // Don't bother with combining configs from different semantic + // contexts if we can fail over to full LL costs more time + // since we'll often fail over anyway. + if configs.HasSemanticContext() { + // dup configs, tossing out semantic predicates + dup := NewBaseATNConfigSet(false) + for _, c := range configs.GetItems() { + + // NewBaseATNConfig({semanticContext:}, c) + c = NewBaseATNConfig2(c, SemanticContextNone) + dup.Add(c, nil) + } + configs = dup + } + // now we have combined contexts for configs with dissimilar preds + } + // pure SLL or combined SLL+LL mode parsing + altsets := PredictionModegetConflictingAltSubsets(configs) + return PredictionModehasConflictingAltSet(altsets) && !PredictionModehasStateAssociatedWithOneAlt(configs) +} + +// Checks if any configuration in {@code configs} is in a +// {@link RuleStopState}. Configurations meeting this condition have reached +// the end of the decision rule (local context) or end of start rule (full +// context). +// +// @param configs the configuration set to test +// @return {@code true} if any configuration in {@code configs} is in a +// {@link RuleStopState}, otherwise {@code false} +func PredictionModehasConfigInRuleStopState(configs ATNConfigSet) bool { + for _, c := range configs.GetItems() { + if _, ok := c.GetState().(*RuleStopState); ok { + return true + } + } + return false +} + +// Checks if all configurations in {@code configs} are in a +// {@link RuleStopState}. Configurations meeting this condition have reached +// the end of the decision rule (local context) or end of start rule (full +// context). +// +// @param configs the configuration set to test +// @return {@code true} if all configurations in {@code configs} are in a +// {@link RuleStopState}, otherwise {@code false} +func PredictionModeallConfigsInRuleStopStates(configs ATNConfigSet) bool { + + for _, c := range configs.GetItems() { + if _, ok := c.GetState().(*RuleStopState); !ok { + return false + } + } + return true +} + +// Full LL prediction termination. +// +//Can we stop looking ahead during ATN simulation or is there some +// uncertainty as to which alternative we will ultimately pick, after +// consuming more input? Even if there are partial conflicts, we might know +// that everything is going to resolve to the same minimum alternative. That +// means we can stop since no more lookahead will change that fact. On the +// other hand, there might be multiple conflicts that resolve to different +// minimums. That means we need more look ahead to decide which of those +// alternatives we should predict.
+// +//The basic idea is to split the set of configurations {@code C}, into +// conflicting subsets {@code (s, _, ctx, _)} and singleton subsets with +// non-conflicting configurations. Two configurations conflict if they have +// identical {@link ATNConfig//state} and {@link ATNConfig//context} values +// but different {@link ATNConfig//alt} value, e.g. {@code (s, i, ctx, _)} +// and {@code (s, j, ctx, _)} for {@code i!=j}.
+// +//Reduce these configuration subsets to the set of possible alternatives. +// You can compute the alternative subsets in one pass as follows:
+// +//{@code A_s,ctx = {i | (s, i, ctx, _)}} for each configuration in +// {@code C} holding {@code s} and {@code ctx} fixed.
+// +//Or in pseudo-code, for each configuration {@code c} in {@code C}:
+// +//
+// map[c] U= c.{@link ATNConfig//alt alt} // map hash/equals uses s and x, not
+// alt and not pred
+//
+//
+// The values in {@code map} are the set of {@code A_s,ctx} sets.
+// +//If {@code |A_s,ctx|=1} then there is no conflict associated with +// {@code s} and {@code ctx}.
+// +//Reduce the subsets to singletons by choosing a minimum of each subset. If +// the union of these alternative subsets is a singleton, then no amount of +// more lookahead will help us. We will always pick that alternative. If, +// however, there is more than one alternative, then we are uncertain which +// alternative to predict and must continue looking for resolution. We may +// or may not discover an ambiguity in the future, even if there are no +// conflicting subsets this round.
+// +//The biggest sin is to terminate early because it means we've made a +// decision but were uncertain as to the eventual outcome. We haven't used +// enough lookahead. On the other hand, announcing a conflict too late is no +// big deal you will still have the conflict. It's just inefficient. It +// might even look until the end of file.
+// +//No special consideration for semantic predicates is required because +// predicates are evaluated on-the-fly for full LL prediction, ensuring that +// no configuration contains a semantic context during the termination +// check.
+// +//CONFLICTING CONFIGS
+// +//Two configurations {@code (s, i, x)} and {@code (s, j, x')}, conflict +// when {@code i!=j} but {@code x=x'}. Because we merge all +// {@code (s, i, _)} configurations together, that means that there are at +// most {@code n} configurations associated with state {@code s} for +// {@code n} possible alternatives in the decision. The merged stacks +// complicate the comparison of configuration contexts {@code x} and +// {@code x'}. Sam checks to see if one is a subset of the other by calling +// merge and checking to see if the merged result is either {@code x} or +// {@code x'}. If the {@code x} associated with lowest alternative {@code i} +// is the superset, then {@code i} is the only possible prediction since the +// others resolve to {@code min(i)} as well. However, if {@code x} is +// associated with {@code j>i} then at least one stack configuration for +// {@code j} is not in conflict with alternative {@code i}. The algorithm +// should keep going, looking for more lookahead due to the uncertainty.
+// +//For simplicity, I'm doing a equality check between {@code x} and +// {@code x'} that lets the algorithm continue to consume lookahead longer +// than necessary. The reason I like the equality is of course the +// simplicity but also because that is the test you need to detect the +// alternatives that are actually in conflict.
+// +//CONTINUE/STOP RULE
+// +//Continue if union of resolved alternative sets from non-conflicting and +// conflicting alternative subsets has more than one alternative. We are +// uncertain about which alternative to predict.
+// +//The complete set of alternatives, {@code [i for (_,i,_)]}, tells us which +// alternatives are still in the running for the amount of input we've +// consumed at this point. The conflicting sets let us to strip away +// configurations that won't lead to more states because we resolve +// conflicts to the configuration with a minimum alternate for the +// conflicting set.
+// +//CASES
+// +//-
+//
+//
- no conflicts and more than 1 alternative in set => continue +// +//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s, 3, z)}, +// {@code (s', 1, y)}, {@code (s', 2, y)} yields non-conflicting set +// {@code {3}} U conflicting sets {@code min({1,2})} U {@code min({1,2})} = +// {@code {1,3}} => continue +// +// +//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 1, y)}, +// {@code (s', 2, y)}, {@code (s”, 1, z)} yields non-conflicting set +// {@code {1}} U conflicting sets {@code min({1,2})} U {@code min({1,2})} = +// {@code {1}} => stop and predict 1 +// +//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 1, y)}, +// {@code (s', 2, y)} yields conflicting, reduced sets {@code {1}} U +// {@code {1}} = {@code {1}} => stop and predict 1, can announce +// ambiguity {@code {1,2}} +// +//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 2, y)}, +// {@code (s', 3, y)} yields conflicting, reduced sets {@code {1}} U +// {@code {2}} = {@code {1,2}} => continue +// +//
- {@code (s, 1, x)}, {@code (s, 2, x)}, {@code (s', 3, y)}, +// {@code (s', 4, y)} yields conflicting, reduced sets {@code {1}} U +// {@code {3}} = {@code {1,3}} => continue +// +//
EXACT AMBIGUITY DETECTION
+// +//If all states Report the same conflicting set of alternatives, then we +// know we have the exact ambiguity set.
+// +//|A_i|>1 and
+// A_i = A_j for all i, j.
In other words, we continue examining lookahead until all {@code A_i} +// have more than one alternative and all {@code A_i} are the same. If +// {@code A={{1,2}, {1,3}}}, then regular LL prediction would terminate +// because the resolved set is {@code {1}}. To determine what the real +// ambiguity is, we have to know whether the ambiguity is between one and +// two or one and three so we keep going. We can only stop prediction when +// we need exact ambiguity detection when the sets look like +// {@code A={{1,2}}} or {@code {{1,2},{1,2}}}, etc...
+func PredictionModeresolvesToJustOneViableAlt(altsets []*BitSet) int { + return PredictionModegetSingleViableAlt(altsets) +} + +// Determines if every alternative subset in {@code altsets} contains more +// than one alternative. +// +// @param altsets a collection of alternative subsets +// @return {@code true} if every {@link BitSet} in {@code altsets} has +// {@link BitSet//cardinality cardinality} > 1, otherwise {@code false} +func PredictionModeallSubsetsConflict(altsets []*BitSet) bool { + return !PredictionModehasNonConflictingAltSet(altsets) +} + +// Determines if any single alternative subset in {@code altsets} contains +// exactly one alternative. +// +// @param altsets a collection of alternative subsets +// @return {@code true} if {@code altsets} contains a {@link BitSet} with +// {@link BitSet//cardinality cardinality} 1, otherwise {@code false} +func PredictionModehasNonConflictingAltSet(altsets []*BitSet) bool { + for i := 0; i < len(altsets); i++ { + alts := altsets[i] + if alts.length() == 1 { + return true + } + } + return false +} + +// Determines if any single alternative subset in {@code altsets} contains +// more than one alternative. +// +// @param altsets a collection of alternative subsets +// @return {@code true} if {@code altsets} contains a {@link BitSet} with +// {@link BitSet//cardinality cardinality} > 1, otherwise {@code false} +func PredictionModehasConflictingAltSet(altsets []*BitSet) bool { + for i := 0; i < len(altsets); i++ { + alts := altsets[i] + if alts.length() > 1 { + return true + } + } + return false +} + +// Determines if every alternative subset in {@code altsets} is equivalent. +// +// @param altsets a collection of alternative subsets +// @return {@code true} if every member of {@code altsets} is equal to the +// others, otherwise {@code false} +func PredictionModeallSubsetsEqual(altsets []*BitSet) bool { + var first *BitSet + + for i := 0; i < len(altsets); i++ { + alts := altsets[i] + if first == nil { + first = alts + } else if alts != first { + return false + } + } + + return true +} + +// Returns the unique alternative predicted by all alternative subsets in +// {@code altsets}. If no such alternative exists, this method returns +// {@link ATN//INVALID_ALT_NUMBER}. +// +// @param altsets a collection of alternative subsets +func PredictionModegetUniqueAlt(altsets []*BitSet) int { + all := PredictionModeGetAlts(altsets) + if all.length() == 1 { + return all.minValue() + } + + return ATNInvalidAltNumber +} + +// Gets the complete set of represented alternatives for a collection of +// alternative subsets. This method returns the union of each {@link BitSet} +// in {@code altsets}. +// +// @param altsets a collection of alternative subsets +// @return the set of represented alternatives in {@code altsets} +func PredictionModeGetAlts(altsets []*BitSet) *BitSet { + all := NewBitSet() + for _, alts := range altsets { + all.or(alts) + } + return all +} + +// PredictionModegetConflictingAltSubsets gets the conflicting alt subsets from a configuration set. +// For each configuration {@code c} in {@code configs}: +// +//
+// map[c] U= c.{@link ATNConfig//alt alt} // map hash/equals uses s and x, not
+// alt and not pred
+//
+func PredictionModegetConflictingAltSubsets(configs ATNConfigSet) []*BitSet {
+ configToAlts := NewJMap[ATNConfig, *BitSet, *ATNAltConfigComparator[ATNConfig]](atnAltCfgEqInst)
+
+ for _, c := range configs.GetItems() {
+
+ alts, ok := configToAlts.Get(c)
+ if !ok {
+ alts = NewBitSet()
+ configToAlts.Put(c, alts)
+ }
+ alts.add(c.GetAlt())
+ }
+
+ return configToAlts.Values()
+}
+
+// PredictionModeGetStateToAltMap gets a map from state to alt subset from a configuration set. For each
+// configuration {@code c} in {@code configs}:
+//
+//
+// map[c.{@link ATNConfig//state state}] U= c.{@link ATNConfig//alt alt}
+//
+func PredictionModeGetStateToAltMap(configs ATNConfigSet) *AltDict {
+ m := NewAltDict()
+
+ for _, c := range configs.GetItems() {
+ alts := m.Get(c.GetState().String())
+ if alts == nil {
+ alts = NewBitSet()
+ m.put(c.GetState().String(), alts)
+ }
+ alts.(*BitSet).add(c.GetAlt())
+ }
+ return m
+}
+
+func PredictionModehasStateAssociatedWithOneAlt(configs ATNConfigSet) bool {
+ values := PredictionModeGetStateToAltMap(configs).values()
+ for i := 0; i < len(values); i++ {
+ if values[i].(*BitSet).length() == 1 {
+ return true
+ }
+ }
+ return false
+}
+
+func PredictionModegetSingleViableAlt(altsets []*BitSet) int {
+ result := ATNInvalidAltNumber
+
+ for i := 0; i < len(altsets); i++ {
+ alts := altsets[i]
+ minAlt := alts.minValue()
+ if result == ATNInvalidAltNumber {
+ result = minAlt
+ } else if result != minAlt { // more than 1 viable alt
+ return ATNInvalidAltNumber
+ }
+ }
+ return result
+}
diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/recognizer.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/recognizer.go
index bfe542d091..e2915bcf14 100644
--- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/recognizer.go
+++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/recognizer.go
@@ -1,216 +1,216 @@
-// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved.
-// Use of this file is governed by the BSD 3-clause license that
-// can be found in the LICENSE.txt file in the project root.
-
-package antlr
-
-import (
- "fmt"
- "strings"
-
- "strconv"
-)
-
-type Recognizer interface {
- GetLiteralNames() []string
- GetSymbolicNames() []string
- GetRuleNames() []string
-
- Sempred(RuleContext, int, int) bool
- Precpred(RuleContext, int) bool
-
- GetState() int
- SetState(int)
- Action(RuleContext, int, int)
- AddErrorListener(ErrorListener)
- RemoveErrorListeners()
- GetATN() *ATN
- GetErrorListenerDispatch() ErrorListener
-}
-
-type BaseRecognizer struct {
- listeners []ErrorListener
- state int
-
- RuleNames []string
- LiteralNames []string
- SymbolicNames []string
- GrammarFileName string
-}
-
-func NewBaseRecognizer() *BaseRecognizer {
- rec := new(BaseRecognizer)
- rec.listeners = []ErrorListener{ConsoleErrorListenerINSTANCE}
- rec.state = -1
- return rec
-}
-
-var tokenTypeMapCache = make(map[string]int)
-var ruleIndexMapCache = make(map[string]int)
-
-func (b *BaseRecognizer) checkVersion(toolVersion string) {
- runtimeVersion := "4.12.0"
- if runtimeVersion != toolVersion {
- fmt.Println("ANTLR runtime and generated code versions disagree: " + runtimeVersion + "!=" + toolVersion)
- }
-}
-
-func (b *BaseRecognizer) Action(context RuleContext, ruleIndex, actionIndex int) {
- panic("action not implemented on Recognizer!")
-}
-
-func (b *BaseRecognizer) AddErrorListener(listener ErrorListener) {
- b.listeners = append(b.listeners, listener)
-}
-
-func (b *BaseRecognizer) RemoveErrorListeners() {
- b.listeners = make([]ErrorListener, 0)
-}
-
-func (b *BaseRecognizer) GetRuleNames() []string {
- return b.RuleNames
-}
-
-func (b *BaseRecognizer) GetTokenNames() []string {
- return b.LiteralNames
-}
-
-func (b *BaseRecognizer) GetSymbolicNames() []string {
- return b.SymbolicNames
-}
-
-func (b *BaseRecognizer) GetLiteralNames() []string {
- return b.LiteralNames
-}
-
-func (b *BaseRecognizer) GetState() int {
- return b.state
-}
-
-func (b *BaseRecognizer) SetState(v int) {
- b.state = v
-}
-
-//func (b *Recognizer) GetTokenTypeMap() {
-// var tokenNames = b.GetTokenNames()
-// if (tokenNames==nil) {
-// panic("The current recognizer does not provide a list of token names.")
-// }
-// var result = tokenTypeMapCache[tokenNames]
-// if(result==nil) {
-// result = tokenNames.reduce(function(o, k, i) { o[k] = i })
-// result.EOF = TokenEOF
-// tokenTypeMapCache[tokenNames] = result
-// }
-// return result
-//}
-
-// Get a map from rule names to rule indexes.
-//
-// Used for XPath and tree pattern compilation.
-func (b *BaseRecognizer) GetRuleIndexMap() map[string]int { - - panic("Method not defined!") - // var ruleNames = b.GetRuleNames() - // if (ruleNames==nil) { - // panic("The current recognizer does not provide a list of rule names.") - // } - // - // var result = ruleIndexMapCache[ruleNames] - // if(result==nil) { - // result = ruleNames.reduce(function(o, k, i) { o[k] = i }) - // ruleIndexMapCache[ruleNames] = result - // } - // return result -} - -func (b *BaseRecognizer) GetTokenType(tokenName string) int { - panic("Method not defined!") - // var ttype = b.GetTokenTypeMap()[tokenName] - // if (ttype !=nil) { - // return ttype - // } else { - // return TokenInvalidType - // } -} - -//func (b *Recognizer) GetTokenTypeMap() map[string]int { -// Vocabulary vocabulary = getVocabulary() -// -// Synchronized (tokenTypeMapCache) { -// MapUsed for XPath and tree pattern compilation.
+func (b *BaseRecognizer) GetRuleIndexMap() map[string]int { + + panic("Method not defined!") + // var ruleNames = b.GetRuleNames() + // if (ruleNames==nil) { + // panic("The current recognizer does not provide a list of rule names.") + // } + // + // var result = ruleIndexMapCache[ruleNames] + // if(result==nil) { + // result = ruleNames.reduce(function(o, k, i) { o[k] = i }) + // ruleIndexMapCache[ruleNames] = result + // } + // return result +} + +func (b *BaseRecognizer) GetTokenType(tokenName string) int { + panic("Method not defined!") + // var ttype = b.GetTokenTypeMap()[tokenName] + // if (ttype !=nil) { + // return ttype + // } else { + // return TokenInvalidType + // } +} + +//func (b *Recognizer) GetTokenTypeMap() map[string]int { +// Vocabulary vocabulary = getVocabulary() +// +// Synchronized (tokenTypeMapCache) { +// Map-// Since tokens on hidden channels (e.g. whitespace or comments) are not -// added to the parse trees, they will not appear in the output of b -// method. -// - -func (b *BaseRuleContext) GetParent() Tree { - return b.parentCtx -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +// A rule context is a record of a single rule invocation. It knows +// which context invoked it, if any. If there is no parent context, then +// naturally the invoking state is not valid. The parent link +// provides a chain upwards from the current rule invocation to the root +// of the invocation tree, forming a stack. We actually carry no +// information about the rule associated with b context (except +// when parsing). We keep only the state number of the invoking state from +// the ATN submachine that invoked b. Contrast b with the s +// pointer inside ParserRuleContext that tracks the current state +// being "executed" for the current rule. +// +// The parent contexts are useful for computing lookahead sets and +// getting error information. +// +// These objects are used during parsing and prediction. +// For the special case of parsers, we use the subclass +// ParserRuleContext. +// +// @see ParserRuleContext +// + +type RuleContext interface { + RuleNode + + GetInvokingState() int + SetInvokingState(int) + + GetRuleIndex() int + IsEmpty() bool + + GetAltNumber() int + SetAltNumber(altNumber int) + + String([]string, RuleContext) string +} + +type BaseRuleContext struct { + parentCtx RuleContext + invokingState int + RuleIndex int +} + +func NewBaseRuleContext(parent RuleContext, invokingState int) *BaseRuleContext { + + rn := new(BaseRuleContext) + + // What context invoked b rule? + rn.parentCtx = parent + + // What state invoked the rule associated with b context? + // The "return address" is the followState of invokingState + // If parent is nil, b should be -1. + if parent == nil { + rn.invokingState = -1 + } else { + rn.invokingState = invokingState + } + + return rn +} + +func (b *BaseRuleContext) GetBaseRuleContext() *BaseRuleContext { + return b +} + +func (b *BaseRuleContext) SetParent(v Tree) { + if v == nil { + b.parentCtx = nil + } else { + b.parentCtx = v.(RuleContext) + } +} + +func (b *BaseRuleContext) GetInvokingState() int { + return b.invokingState +} + +func (b *BaseRuleContext) SetInvokingState(t int) { + b.invokingState = t +} + +func (b *BaseRuleContext) GetRuleIndex() int { + return b.RuleIndex +} + +func (b *BaseRuleContext) GetAltNumber() int { + return ATNInvalidAltNumber +} + +func (b *BaseRuleContext) SetAltNumber(altNumber int) {} + +// A context is empty if there is no invoking state meaning nobody call +// current context. +func (b *BaseRuleContext) IsEmpty() bool { + return b.invokingState == -1 +} + +// Return the combined text of all child nodes. This method only considers +// tokens which have been added to the parse tree. +//
+// Since tokens on hidden channels (e.g. whitespace or comments) are not +// added to the parse trees, they will not appear in the output of b +// method. +// + +func (b *BaseRuleContext) GetParent() Tree { + return b.parentCtx +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/semantic_context.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/semantic_context.go index a702e99def..277677f448 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/semantic_context.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/semantic_context.go @@ -1,469 +1,469 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "fmt" - "strconv" -) - -// A tree structure used to record the semantic context in which -// an ATN configuration is valid. It's either a single predicate, -// a conjunction {@code p1&&p2}, or a sum of products {@code p1||p2}. -// -//
I have scoped the {@link AND}, {@link OR}, and {@link Predicate} subclasses of -// {@link SemanticContext} within the scope of this outer class.
-// - -type SemanticContext interface { - Equals(other Collectable[SemanticContext]) bool - Hash() int - - evaluate(parser Recognizer, outerContext RuleContext) bool - evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext - - String() string -} - -func SemanticContextandContext(a, b SemanticContext) SemanticContext { - if a == nil || a == SemanticContextNone { - return b - } - if b == nil || b == SemanticContextNone { - return a - } - result := NewAND(a, b) - if len(result.opnds) == 1 { - return result.opnds[0] - } - - return result -} - -func SemanticContextorContext(a, b SemanticContext) SemanticContext { - if a == nil { - return b - } - if b == nil { - return a - } - if a == SemanticContextNone || b == SemanticContextNone { - return SemanticContextNone - } - result := NewOR(a, b) - if len(result.opnds) == 1 { - return result.opnds[0] - } - - return result -} - -type Predicate struct { - ruleIndex int - predIndex int - isCtxDependent bool -} - -func NewPredicate(ruleIndex, predIndex int, isCtxDependent bool) *Predicate { - p := new(Predicate) - - p.ruleIndex = ruleIndex - p.predIndex = predIndex - p.isCtxDependent = isCtxDependent // e.g., $i ref in pred - return p -} - -//The default {@link SemanticContext}, which is semantically equivalent to -//a predicate of the form {@code {true}?}. - -var SemanticContextNone = NewPredicate(-1, -1, false) - -func (p *Predicate) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { - return p -} - -func (p *Predicate) evaluate(parser Recognizer, outerContext RuleContext) bool { - - var localctx RuleContext - - if p.isCtxDependent { - localctx = outerContext - } - - return parser.Sempred(localctx, p.ruleIndex, p.predIndex) -} - -func (p *Predicate) Equals(other Collectable[SemanticContext]) bool { - if p == other { - return true - } else if _, ok := other.(*Predicate); !ok { - return false - } else { - return p.ruleIndex == other.(*Predicate).ruleIndex && - p.predIndex == other.(*Predicate).predIndex && - p.isCtxDependent == other.(*Predicate).isCtxDependent - } -} - -func (p *Predicate) Hash() int { - h := murmurInit(0) - h = murmurUpdate(h, p.ruleIndex) - h = murmurUpdate(h, p.predIndex) - if p.isCtxDependent { - h = murmurUpdate(h, 1) - } else { - h = murmurUpdate(h, 0) - } - return murmurFinish(h, 3) -} - -func (p *Predicate) String() string { - return "{" + strconv.Itoa(p.ruleIndex) + ":" + strconv.Itoa(p.predIndex) + "}?" -} - -type PrecedencePredicate struct { - precedence int -} - -func NewPrecedencePredicate(precedence int) *PrecedencePredicate { - - p := new(PrecedencePredicate) - p.precedence = precedence - - return p -} - -func (p *PrecedencePredicate) evaluate(parser Recognizer, outerContext RuleContext) bool { - return parser.Precpred(outerContext, p.precedence) -} - -func (p *PrecedencePredicate) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { - if parser.Precpred(outerContext, p.precedence) { - return SemanticContextNone - } - - return nil -} - -func (p *PrecedencePredicate) compareTo(other *PrecedencePredicate) int { - return p.precedence - other.precedence -} - -func (p *PrecedencePredicate) Equals(other Collectable[SemanticContext]) bool { - - var op *PrecedencePredicate - var ok bool - if op, ok = other.(*PrecedencePredicate); !ok { - return false - } - - if p == op { - return true - } - - return p.precedence == other.(*PrecedencePredicate).precedence -} - -func (p *PrecedencePredicate) Hash() int { - h := uint32(1) - h = 31*h + uint32(p.precedence) - return int(h) -} - -func (p *PrecedencePredicate) String() string { - return "{" + strconv.Itoa(p.precedence) + ">=prec}?" -} - -func PrecedencePredicatefilterPrecedencePredicates(set *JStore[SemanticContext, Comparator[SemanticContext]]) []*PrecedencePredicate { - result := make([]*PrecedencePredicate, 0) - - set.Each(func(v SemanticContext) bool { - if c2, ok := v.(*PrecedencePredicate); ok { - result = append(result, c2) - } - return true - }) - - return result -} - -// A semantic context which is true whenever none of the contained contexts -// is false.` - -type AND struct { - opnds []SemanticContext -} - -func NewAND(a, b SemanticContext) *AND { - - operands := NewJStore[SemanticContext, Comparator[SemanticContext]](semctxEqInst) - if aa, ok := a.(*AND); ok { - for _, o := range aa.opnds { - operands.Put(o) - } - } else { - operands.Put(a) - } - - if ba, ok := b.(*AND); ok { - for _, o := range ba.opnds { - operands.Put(o) - } - } else { - operands.Put(b) - } - precedencePredicates := PrecedencePredicatefilterPrecedencePredicates(operands) - if len(precedencePredicates) > 0 { - // interested in the transition with the lowest precedence - var reduced *PrecedencePredicate - - for _, p := range precedencePredicates { - if reduced == nil || p.precedence < reduced.precedence { - reduced = p - } - } - - operands.Put(reduced) - } - - vs := operands.Values() - opnds := make([]SemanticContext, len(vs)) - for i, v := range vs { - opnds[i] = v.(SemanticContext) - } - - and := new(AND) - and.opnds = opnds - - return and -} - -func (a *AND) Equals(other Collectable[SemanticContext]) bool { - if a == other { - return true - } - if _, ok := other.(*AND); !ok { - return false - } else { - for i, v := range other.(*AND).opnds { - if !a.opnds[i].Equals(v) { - return false - } - } - return true - } -} - -// {@inheritDoc} -// -//-// The evaluation of predicates by a context is short-circuiting, but -// unordered.
-func (a *AND) evaluate(parser Recognizer, outerContext RuleContext) bool { - for i := 0; i < len(a.opnds); i++ { - if !a.opnds[i].evaluate(parser, outerContext) { - return false - } - } - return true -} - -func (a *AND) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { - differs := false - operands := make([]SemanticContext, 0) - - for i := 0; i < len(a.opnds); i++ { - context := a.opnds[i] - evaluated := context.evalPrecedence(parser, outerContext) - differs = differs || (evaluated != context) - if evaluated == nil { - // The AND context is false if any element is false - return nil - } else if evaluated != SemanticContextNone { - // Reduce the result by Skipping true elements - operands = append(operands, evaluated) - } - } - if !differs { - return a - } - - if len(operands) == 0 { - // all elements were true, so the AND context is true - return SemanticContextNone - } - - var result SemanticContext - - for _, o := range operands { - if result == nil { - result = o - } else { - result = SemanticContextandContext(result, o) - } - } - - return result -} - -func (a *AND) Hash() int { - h := murmurInit(37) // Init with a value different from OR - for _, op := range a.opnds { - h = murmurUpdate(h, op.Hash()) - } - return murmurFinish(h, len(a.opnds)) -} - -func (a *OR) Hash() int { - h := murmurInit(41) // Init with a value different from AND - for _, op := range a.opnds { - h = murmurUpdate(h, op.Hash()) - } - return murmurFinish(h, len(a.opnds)) -} - -func (a *AND) String() string { - s := "" - - for _, o := range a.opnds { - s += "&& " + fmt.Sprint(o) - } - - if len(s) > 3 { - return s[0:3] - } - - return s -} - -// -// A semantic context which is true whenever at least one of the contained -// contexts is true. -// - -type OR struct { - opnds []SemanticContext -} - -func NewOR(a, b SemanticContext) *OR { - - operands := NewJStore[SemanticContext, Comparator[SemanticContext]](semctxEqInst) - if aa, ok := a.(*OR); ok { - for _, o := range aa.opnds { - operands.Put(o) - } - } else { - operands.Put(a) - } - - if ba, ok := b.(*OR); ok { - for _, o := range ba.opnds { - operands.Put(o) - } - } else { - operands.Put(b) - } - precedencePredicates := PrecedencePredicatefilterPrecedencePredicates(operands) - if len(precedencePredicates) > 0 { - // interested in the transition with the lowest precedence - var reduced *PrecedencePredicate - - for _, p := range precedencePredicates { - if reduced == nil || p.precedence > reduced.precedence { - reduced = p - } - } - - operands.Put(reduced) - } - - vs := operands.Values() - - opnds := make([]SemanticContext, len(vs)) - for i, v := range vs { - opnds[i] = v.(SemanticContext) - } - - o := new(OR) - o.opnds = opnds - - return o -} - -func (o *OR) Equals(other Collectable[SemanticContext]) bool { - if o == other { - return true - } else if _, ok := other.(*OR); !ok { - return false - } else { - for i, v := range other.(*OR).opnds { - if !o.opnds[i].Equals(v) { - return false - } - } - return true - } -} - -//-// The evaluation of predicates by o context is short-circuiting, but -// unordered.
-func (o *OR) evaluate(parser Recognizer, outerContext RuleContext) bool { - for i := 0; i < len(o.opnds); i++ { - if o.opnds[i].evaluate(parser, outerContext) { - return true - } - } - return false -} - -func (o *OR) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { - differs := false - operands := make([]SemanticContext, 0) - for i := 0; i < len(o.opnds); i++ { - context := o.opnds[i] - evaluated := context.evalPrecedence(parser, outerContext) - differs = differs || (evaluated != context) - if evaluated == SemanticContextNone { - // The OR context is true if any element is true - return SemanticContextNone - } else if evaluated != nil { - // Reduce the result by Skipping false elements - operands = append(operands, evaluated) - } - } - if !differs { - return o - } - if len(operands) == 0 { - // all elements were false, so the OR context is false - return nil - } - var result SemanticContext - - for _, o := range operands { - if result == nil { - result = o - } else { - result = SemanticContextorContext(result, o) - } - } - - return result -} - -func (o *OR) String() string { - s := "" - - for _, o := range o.opnds { - s += "|| " + fmt.Sprint(o) - } - - if len(s) > 3 { - return s[0:3] - } - - return s -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "fmt" + "strconv" +) + +// A tree structure used to record the semantic context in which +// an ATN configuration is valid. It's either a single predicate, +// a conjunction {@code p1&&p2}, or a sum of products {@code p1||p2}. +// +//I have scoped the {@link AND}, {@link OR}, and {@link Predicate} subclasses of +// {@link SemanticContext} within the scope of this outer class.
+// + +type SemanticContext interface { + Equals(other Collectable[SemanticContext]) bool + Hash() int + + evaluate(parser Recognizer, outerContext RuleContext) bool + evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext + + String() string +} + +func SemanticContextandContext(a, b SemanticContext) SemanticContext { + if a == nil || a == SemanticContextNone { + return b + } + if b == nil || b == SemanticContextNone { + return a + } + result := NewAND(a, b) + if len(result.opnds) == 1 { + return result.opnds[0] + } + + return result +} + +func SemanticContextorContext(a, b SemanticContext) SemanticContext { + if a == nil { + return b + } + if b == nil { + return a + } + if a == SemanticContextNone || b == SemanticContextNone { + return SemanticContextNone + } + result := NewOR(a, b) + if len(result.opnds) == 1 { + return result.opnds[0] + } + + return result +} + +type Predicate struct { + ruleIndex int + predIndex int + isCtxDependent bool +} + +func NewPredicate(ruleIndex, predIndex int, isCtxDependent bool) *Predicate { + p := new(Predicate) + + p.ruleIndex = ruleIndex + p.predIndex = predIndex + p.isCtxDependent = isCtxDependent // e.g., $i ref in pred + return p +} + +//The default {@link SemanticContext}, which is semantically equivalent to +//a predicate of the form {@code {true}?}. + +var SemanticContextNone = NewPredicate(-1, -1, false) + +func (p *Predicate) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { + return p +} + +func (p *Predicate) evaluate(parser Recognizer, outerContext RuleContext) bool { + + var localctx RuleContext + + if p.isCtxDependent { + localctx = outerContext + } + + return parser.Sempred(localctx, p.ruleIndex, p.predIndex) +} + +func (p *Predicate) Equals(other Collectable[SemanticContext]) bool { + if p == other { + return true + } else if _, ok := other.(*Predicate); !ok { + return false + } else { + return p.ruleIndex == other.(*Predicate).ruleIndex && + p.predIndex == other.(*Predicate).predIndex && + p.isCtxDependent == other.(*Predicate).isCtxDependent + } +} + +func (p *Predicate) Hash() int { + h := murmurInit(0) + h = murmurUpdate(h, p.ruleIndex) + h = murmurUpdate(h, p.predIndex) + if p.isCtxDependent { + h = murmurUpdate(h, 1) + } else { + h = murmurUpdate(h, 0) + } + return murmurFinish(h, 3) +} + +func (p *Predicate) String() string { + return "{" + strconv.Itoa(p.ruleIndex) + ":" + strconv.Itoa(p.predIndex) + "}?" +} + +type PrecedencePredicate struct { + precedence int +} + +func NewPrecedencePredicate(precedence int) *PrecedencePredicate { + + p := new(PrecedencePredicate) + p.precedence = precedence + + return p +} + +func (p *PrecedencePredicate) evaluate(parser Recognizer, outerContext RuleContext) bool { + return parser.Precpred(outerContext, p.precedence) +} + +func (p *PrecedencePredicate) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { + if parser.Precpred(outerContext, p.precedence) { + return SemanticContextNone + } + + return nil +} + +func (p *PrecedencePredicate) compareTo(other *PrecedencePredicate) int { + return p.precedence - other.precedence +} + +func (p *PrecedencePredicate) Equals(other Collectable[SemanticContext]) bool { + + var op *PrecedencePredicate + var ok bool + if op, ok = other.(*PrecedencePredicate); !ok { + return false + } + + if p == op { + return true + } + + return p.precedence == other.(*PrecedencePredicate).precedence +} + +func (p *PrecedencePredicate) Hash() int { + h := uint32(1) + h = 31*h + uint32(p.precedence) + return int(h) +} + +func (p *PrecedencePredicate) String() string { + return "{" + strconv.Itoa(p.precedence) + ">=prec}?" +} + +func PrecedencePredicatefilterPrecedencePredicates(set *JStore[SemanticContext, Comparator[SemanticContext]]) []*PrecedencePredicate { + result := make([]*PrecedencePredicate, 0) + + set.Each(func(v SemanticContext) bool { + if c2, ok := v.(*PrecedencePredicate); ok { + result = append(result, c2) + } + return true + }) + + return result +} + +// A semantic context which is true whenever none of the contained contexts +// is false.` + +type AND struct { + opnds []SemanticContext +} + +func NewAND(a, b SemanticContext) *AND { + + operands := NewJStore[SemanticContext, Comparator[SemanticContext]](semctxEqInst) + if aa, ok := a.(*AND); ok { + for _, o := range aa.opnds { + operands.Put(o) + } + } else { + operands.Put(a) + } + + if ba, ok := b.(*AND); ok { + for _, o := range ba.opnds { + operands.Put(o) + } + } else { + operands.Put(b) + } + precedencePredicates := PrecedencePredicatefilterPrecedencePredicates(operands) + if len(precedencePredicates) > 0 { + // interested in the transition with the lowest precedence + var reduced *PrecedencePredicate + + for _, p := range precedencePredicates { + if reduced == nil || p.precedence < reduced.precedence { + reduced = p + } + } + + operands.Put(reduced) + } + + vs := operands.Values() + opnds := make([]SemanticContext, len(vs)) + for i, v := range vs { + opnds[i] = v.(SemanticContext) + } + + and := new(AND) + and.opnds = opnds + + return and +} + +func (a *AND) Equals(other Collectable[SemanticContext]) bool { + if a == other { + return true + } + if _, ok := other.(*AND); !ok { + return false + } else { + for i, v := range other.(*AND).opnds { + if !a.opnds[i].Equals(v) { + return false + } + } + return true + } +} + +// {@inheritDoc} +// +//+// The evaluation of predicates by a context is short-circuiting, but +// unordered.
+func (a *AND) evaluate(parser Recognizer, outerContext RuleContext) bool { + for i := 0; i < len(a.opnds); i++ { + if !a.opnds[i].evaluate(parser, outerContext) { + return false + } + } + return true +} + +func (a *AND) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { + differs := false + operands := make([]SemanticContext, 0) + + for i := 0; i < len(a.opnds); i++ { + context := a.opnds[i] + evaluated := context.evalPrecedence(parser, outerContext) + differs = differs || (evaluated != context) + if evaluated == nil { + // The AND context is false if any element is false + return nil + } else if evaluated != SemanticContextNone { + // Reduce the result by Skipping true elements + operands = append(operands, evaluated) + } + } + if !differs { + return a + } + + if len(operands) == 0 { + // all elements were true, so the AND context is true + return SemanticContextNone + } + + var result SemanticContext + + for _, o := range operands { + if result == nil { + result = o + } else { + result = SemanticContextandContext(result, o) + } + } + + return result +} + +func (a *AND) Hash() int { + h := murmurInit(37) // Init with a value different from OR + for _, op := range a.opnds { + h = murmurUpdate(h, op.Hash()) + } + return murmurFinish(h, len(a.opnds)) +} + +func (a *OR) Hash() int { + h := murmurInit(41) // Init with a value different from AND + for _, op := range a.opnds { + h = murmurUpdate(h, op.Hash()) + } + return murmurFinish(h, len(a.opnds)) +} + +func (a *AND) String() string { + s := "" + + for _, o := range a.opnds { + s += "&& " + fmt.Sprint(o) + } + + if len(s) > 3 { + return s[0:3] + } + + return s +} + +// +// A semantic context which is true whenever at least one of the contained +// contexts is true. +// + +type OR struct { + opnds []SemanticContext +} + +func NewOR(a, b SemanticContext) *OR { + + operands := NewJStore[SemanticContext, Comparator[SemanticContext]](semctxEqInst) + if aa, ok := a.(*OR); ok { + for _, o := range aa.opnds { + operands.Put(o) + } + } else { + operands.Put(a) + } + + if ba, ok := b.(*OR); ok { + for _, o := range ba.opnds { + operands.Put(o) + } + } else { + operands.Put(b) + } + precedencePredicates := PrecedencePredicatefilterPrecedencePredicates(operands) + if len(precedencePredicates) > 0 { + // interested in the transition with the lowest precedence + var reduced *PrecedencePredicate + + for _, p := range precedencePredicates { + if reduced == nil || p.precedence > reduced.precedence { + reduced = p + } + } + + operands.Put(reduced) + } + + vs := operands.Values() + + opnds := make([]SemanticContext, len(vs)) + for i, v := range vs { + opnds[i] = v.(SemanticContext) + } + + o := new(OR) + o.opnds = opnds + + return o +} + +func (o *OR) Equals(other Collectable[SemanticContext]) bool { + if o == other { + return true + } else if _, ok := other.(*OR); !ok { + return false + } else { + for i, v := range other.(*OR).opnds { + if !o.opnds[i].Equals(v) { + return false + } + } + return true + } +} + +//+// The evaluation of predicates by o context is short-circuiting, but +// unordered.
+func (o *OR) evaluate(parser Recognizer, outerContext RuleContext) bool { + for i := 0; i < len(o.opnds); i++ { + if o.opnds[i].evaluate(parser, outerContext) { + return true + } + } + return false +} + +func (o *OR) evalPrecedence(parser Recognizer, outerContext RuleContext) SemanticContext { + differs := false + operands := make([]SemanticContext, 0) + for i := 0; i < len(o.opnds); i++ { + context := o.opnds[i] + evaluated := context.evalPrecedence(parser, outerContext) + differs = differs || (evaluated != context) + if evaluated == SemanticContextNone { + // The OR context is true if any element is true + return SemanticContextNone + } else if evaluated != nil { + // Reduce the result by Skipping false elements + operands = append(operands, evaluated) + } + } + if !differs { + return o + } + if len(operands) == 0 { + // all elements were false, so the OR context is false + return nil + } + var result SemanticContext + + for _, o := range operands { + if result == nil { + result = o + } else { + result = SemanticContextorContext(result, o) + } + } + + return result +} + +func (o *OR) String() string { + s := "" + + for _, o := range o.opnds { + s += "|| " + fmt.Sprint(o) + } + + if len(s) > 3 { + return s[0:3] + } + + return s +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/token.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/token.go index f73b06bc6a..c642ac819d 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/token.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/token.go @@ -1,209 +1,209 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -import ( - "strconv" - "strings" -) - -type TokenSourceCharStreamPair struct { - tokenSource TokenSource - charStream CharStream -} - -// A token has properties: text, type, line, character position in the line -// (so we can ignore tabs), token channel, index, and source from which -// we obtained this token. - -type Token interface { - GetSource() *TokenSourceCharStreamPair - GetTokenType() int - GetChannel() int - GetStart() int - GetStop() int - GetLine() int - GetColumn() int - - GetText() string - SetText(s string) - - GetTokenIndex() int - SetTokenIndex(v int) - - GetTokenSource() TokenSource - GetInputStream() CharStream -} - -type BaseToken struct { - source *TokenSourceCharStreamPair - tokenType int // token type of the token - channel int // The parser ignores everything not on DEFAULT_CHANNEL - start int // optional return -1 if not implemented. - stop int // optional return -1 if not implemented. - tokenIndex int // from 0..n-1 of the token object in the input stream - line int // line=1..n of the 1st character - column int // beginning of the line at which it occurs, 0..n-1 - text string // text of the token. - readOnly bool -} - -const ( - TokenInvalidType = 0 - - // During lookahead operations, this "token" signifies we hit rule end ATN state - // and did not follow it despite needing to. - TokenEpsilon = -2 - - TokenMinUserTokenType = 1 - - TokenEOF = -1 - - // All tokens go to the parser (unless Skip() is called in that rule) - // on a particular "channel". The parser tunes to a particular channel - // so that whitespace etc... can go to the parser on a "hidden" channel. - - TokenDefaultChannel = 0 - - // Anything on different channel than DEFAULT_CHANNEL is not parsed - // by parser. - - TokenHiddenChannel = 1 -) - -func (b *BaseToken) GetChannel() int { - return b.channel -} - -func (b *BaseToken) GetStart() int { - return b.start -} - -func (b *BaseToken) GetStop() int { - return b.stop -} - -func (b *BaseToken) GetLine() int { - return b.line -} - -func (b *BaseToken) GetColumn() int { - return b.column -} - -func (b *BaseToken) GetTokenType() int { - return b.tokenType -} - -func (b *BaseToken) GetSource() *TokenSourceCharStreamPair { - return b.source -} - -func (b *BaseToken) GetTokenIndex() int { - return b.tokenIndex -} - -func (b *BaseToken) SetTokenIndex(v int) { - b.tokenIndex = v -} - -func (b *BaseToken) GetTokenSource() TokenSource { - return b.source.tokenSource -} - -func (b *BaseToken) GetInputStream() CharStream { - return b.source.charStream -} - -type CommonToken struct { - *BaseToken -} - -func NewCommonToken(source *TokenSourceCharStreamPair, tokenType, channel, start, stop int) *CommonToken { - - t := new(CommonToken) - - t.BaseToken = new(BaseToken) - - t.source = source - t.tokenType = tokenType - t.channel = channel - t.start = start - t.stop = stop - t.tokenIndex = -1 - if t.source.tokenSource != nil { - t.line = source.tokenSource.GetLine() - t.column = source.tokenSource.GetCharPositionInLine() - } else { - t.column = -1 - } - return t -} - -// An empty {@link Pair} which is used as the default value of -// {@link //source} for tokens that do not have a source. - -//CommonToken.EMPTY_SOURCE = [ nil, nil ] - -// Constructs a New{@link CommonToken} as a copy of another {@link Token}. -// -//-// If {@code oldToken} is also a {@link CommonToken} instance, the newly -// constructed token will share a reference to the {@link //text} field and -// the {@link Pair} stored in {@link //source}. Otherwise, {@link //text} will -// be assigned the result of calling {@link //GetText}, and {@link //source} -// will be constructed from the result of {@link Token//GetTokenSource} and -// {@link Token//GetInputStream}.
-// -// @param oldToken The token to copy. -func (c *CommonToken) clone() *CommonToken { - t := NewCommonToken(c.source, c.tokenType, c.channel, c.start, c.stop) - t.tokenIndex = c.GetTokenIndex() - t.line = c.GetLine() - t.column = c.GetColumn() - t.text = c.GetText() - return t -} - -func (c *CommonToken) GetText() string { - if c.text != "" { - return c.text - } - input := c.GetInputStream() - if input == nil { - return "" - } - n := input.Size() - if c.start < n && c.stop < n { - return input.GetTextFromInterval(NewInterval(c.start, c.stop)) - } - return "+// If {@code oldToken} is also a {@link CommonToken} instance, the newly +// constructed token will share a reference to the {@link //text} field and +// the {@link Pair} stored in {@link //source}. Otherwise, {@link //text} will +// be assigned the result of calling {@link //GetText}, and {@link //source} +// will be constructed from the result of {@link Token//GetTokenSource} and +// {@link Token//GetInputStream}.
+// +// @param oldToken The token to copy. +func (c *CommonToken) clone() *CommonToken { + t := NewCommonToken(c.source, c.tokenType, c.channel, c.start, c.stop) + t.tokenIndex = c.GetTokenIndex() + t.line = c.GetLine() + t.column = c.GetColumn() + t.text = c.GetText() + return t +} + +func (c *CommonToken) GetText() string { + if c.text != "" { + return c.text + } + input := c.GetInputStream() + if input == nil { + return "" + } + n := input.Size() + if c.start < n && c.stop < n { + return input.GetTextFromInterval(NewInterval(c.start, c.stop)) + } + return "-// You can insert stuff, replace, and delete chunks. Note that the operations -// are done lazily--only if you convert the buffer to a {@link String} with -// {@link TokenStream#getText()}. This is very efficient because you are not -// moving data around all the time. As the buffer of tokens is converted to -// strings, the {@link #getText()} method(s) scan the input token stream and -// check to see if there is an operation at the current index. If so, the -// operation is done and then normal {@link String} rendering continues on the -// buffer. This is like having multiple Turing machine instruction streams -// (programs) operating on a single input tape. :)
-//- -// This rewriter makes no modifications to the token stream. It does not ask the -// stream to fill itself up nor does it advance the input cursor. The token -// stream {@link TokenStream#index()} will return the same value before and -// after any {@link #getText()} call.
- -//-// The rewriter only works on tokens that you have in the buffer and ignores the -// current input cursor. If you are buffering tokens on-demand, calling -// {@link #getText()} halfway through the input will only do rewrites for those -// tokens in the first half of the file.
- -//-// Since the operations are done lazily at {@link #getText}-time, operations do -// not screw up the token index values. That is, an insert operation at token -// index {@code i} does not change the index values for tokens -// {@code i}+1..n-1.
- -//-// Because operations never actually alter the buffer, you may always get the -// original token stream back without undoing anything. Since the instructions -// are queued up, you can easily simulate transactions and roll back any changes -// if there is an error just by removing instructions. For example,
- -//
-// CharStream input = new ANTLRFileStream("input");
-// TLexer lex = new TLexer(input);
-// CommonTokenStream tokens = new CommonTokenStream(lex);
-// T parser = new T(tokens);
-// TokenStreamRewriter rewriter = new TokenStreamRewriter(tokens);
-// parser.startRule();
-//
-
-// -// Then in the rules, you can execute (assuming rewriter is visible):
- -//-// Token t,u; -// ... -// rewriter.insertAfter(t, "text to put after t");} -// rewriter.insertAfter(u, "text after u");} -// System.out.println(rewriter.getText()); -//- -//
-// You can also have multiple "instruction streams" and get multiple rewrites -// from a single pass over the input. Just name the instruction streams and use -// that name again when printing the buffer. This could be useful for generating -// a C file and also its header file--all from the same buffer:
- -//
-// rewriter.insertAfter("pass1", t, "text to put after t");}
-// rewriter.insertAfter("pass2", u, "text after u");}
-// System.out.println(rewriter.getText("pass1"));
-// System.out.println(rewriter.getText("pass2"));
-//
-
-// -// If you don't use named rewrite streams, a "default" stream is used as the -// first example shows.
- -const ( - Default_Program_Name = "default" - Program_Init_Size = 100 - Min_Token_Index = 0 -) - -// Define the rewrite operation hierarchy - -type RewriteOperation interface { - // Execute the rewrite operation by possibly adding to the buffer. - // Return the index of the next token to operate on. - Execute(buffer *bytes.Buffer) int - String() string - GetInstructionIndex() int - GetIndex() int - GetText() string - GetOpName() string - GetTokens() TokenStream - SetInstructionIndex(val int) - SetIndex(int) - SetText(string) - SetOpName(string) - SetTokens(TokenStream) -} - -type BaseRewriteOperation struct { - //Current index of rewrites list - instruction_index int - //Token buffer index - index int - //Substitution text - text string - //Actual operation name - op_name string - //Pointer to token steam - tokens TokenStream -} - -func (op *BaseRewriteOperation) GetInstructionIndex() int { - return op.instruction_index -} - -func (op *BaseRewriteOperation) GetIndex() int { - return op.index -} - -func (op *BaseRewriteOperation) GetText() string { - return op.text -} - -func (op *BaseRewriteOperation) GetOpName() string { - return op.op_name -} - -func (op *BaseRewriteOperation) GetTokens() TokenStream { - return op.tokens -} - -func (op *BaseRewriteOperation) SetInstructionIndex(val int) { - op.instruction_index = val -} - -func (op *BaseRewriteOperation) SetIndex(val int) { - op.index = val -} - -func (op *BaseRewriteOperation) SetText(val string) { - op.text = val -} - -func (op *BaseRewriteOperation) SetOpName(val string) { - op.op_name = val -} - -func (op *BaseRewriteOperation) SetTokens(val TokenStream) { - op.tokens = val -} - -func (op *BaseRewriteOperation) Execute(buffer *bytes.Buffer) int { - return op.index -} - -func (op *BaseRewriteOperation) String() string { - return fmt.Sprintf("<%s@%d:\"%s\">", - op.op_name, - op.tokens.Get(op.GetIndex()), - op.text, - ) - -} - -type InsertBeforeOp struct { - BaseRewriteOperation -} - -func NewInsertBeforeOp(index int, text string, stream TokenStream) *InsertBeforeOp { - return &InsertBeforeOp{BaseRewriteOperation: BaseRewriteOperation{ - index: index, - text: text, - op_name: "InsertBeforeOp", - tokens: stream, - }} -} - -func (op *InsertBeforeOp) Execute(buffer *bytes.Buffer) int { - buffer.WriteString(op.text) - if op.tokens.Get(op.index).GetTokenType() != TokenEOF { - buffer.WriteString(op.tokens.Get(op.index).GetText()) - } - return op.index + 1 -} - -func (op *InsertBeforeOp) String() string { - return op.BaseRewriteOperation.String() -} - -// Distinguish between insert after/before to do the "insert afters" -// first and then the "insert befores" at same index. Implementation -// of "insert after" is "insert before index+1". - -type InsertAfterOp struct { - BaseRewriteOperation -} - -func NewInsertAfterOp(index int, text string, stream TokenStream) *InsertAfterOp { - return &InsertAfterOp{BaseRewriteOperation: BaseRewriteOperation{ - index: index + 1, - text: text, - tokens: stream, - }} -} - -func (op *InsertAfterOp) Execute(buffer *bytes.Buffer) int { - buffer.WriteString(op.text) - if op.tokens.Get(op.index).GetTokenType() != TokenEOF { - buffer.WriteString(op.tokens.Get(op.index).GetText()) - } - return op.index + 1 -} - -func (op *InsertAfterOp) String() string { - return op.BaseRewriteOperation.String() -} - -// I'm going to try replacing range from x..y with (y-x)+1 ReplaceOp -// instructions. -type ReplaceOp struct { - BaseRewriteOperation - LastIndex int -} - -func NewReplaceOp(from, to int, text string, stream TokenStream) *ReplaceOp { - return &ReplaceOp{ - BaseRewriteOperation: BaseRewriteOperation{ - index: from, - text: text, - op_name: "ReplaceOp", - tokens: stream, - }, - LastIndex: to, - } -} - -func (op *ReplaceOp) Execute(buffer *bytes.Buffer) int { - if op.text != "" { - buffer.WriteString(op.text) - } - return op.LastIndex + 1 -} - -func (op *ReplaceOp) String() string { - if op.text == "" { - return fmt.Sprintf("+// You can insert stuff, replace, and delete chunks. Note that the operations +// are done lazily--only if you convert the buffer to a {@link String} with +// {@link TokenStream#getText()}. This is very efficient because you are not +// moving data around all the time. As the buffer of tokens is converted to +// strings, the {@link #getText()} method(s) scan the input token stream and +// check to see if there is an operation at the current index. If so, the +// operation is done and then normal {@link String} rendering continues on the +// buffer. This is like having multiple Turing machine instruction streams +// (programs) operating on a single input tape. :)
+//+ +// This rewriter makes no modifications to the token stream. It does not ask the +// stream to fill itself up nor does it advance the input cursor. The token +// stream {@link TokenStream#index()} will return the same value before and +// after any {@link #getText()} call.
+ +//+// The rewriter only works on tokens that you have in the buffer and ignores the +// current input cursor. If you are buffering tokens on-demand, calling +// {@link #getText()} halfway through the input will only do rewrites for those +// tokens in the first half of the file.
+ +//+// Since the operations are done lazily at {@link #getText}-time, operations do +// not screw up the token index values. That is, an insert operation at token +// index {@code i} does not change the index values for tokens +// {@code i}+1..n-1.
+ +//+// Because operations never actually alter the buffer, you may always get the +// original token stream back without undoing anything. Since the instructions +// are queued up, you can easily simulate transactions and roll back any changes +// if there is an error just by removing instructions. For example,
+ +//
+// CharStream input = new ANTLRFileStream("input");
+// TLexer lex = new TLexer(input);
+// CommonTokenStream tokens = new CommonTokenStream(lex);
+// T parser = new T(tokens);
+// TokenStreamRewriter rewriter = new TokenStreamRewriter(tokens);
+// parser.startRule();
+//
+
+// +// Then in the rules, you can execute (assuming rewriter is visible):
+ +//+// Token t,u; +// ... +// rewriter.insertAfter(t, "text to put after t");} +// rewriter.insertAfter(u, "text after u");} +// System.out.println(rewriter.getText()); +//+ +//
+// You can also have multiple "instruction streams" and get multiple rewrites +// from a single pass over the input. Just name the instruction streams and use +// that name again when printing the buffer. This could be useful for generating +// a C file and also its header file--all from the same buffer:
+ +//
+// rewriter.insertAfter("pass1", t, "text to put after t");}
+// rewriter.insertAfter("pass2", u, "text after u");}
+// System.out.println(rewriter.getText("pass1"));
+// System.out.println(rewriter.getText("pass2"));
+//
+
+// +// If you don't use named rewrite streams, a "default" stream is used as the +// first example shows.
+ +const ( + Default_Program_Name = "default" + Program_Init_Size = 100 + Min_Token_Index = 0 +) + +// Define the rewrite operation hierarchy + +type RewriteOperation interface { + // Execute the rewrite operation by possibly adding to the buffer. + // Return the index of the next token to operate on. + Execute(buffer *bytes.Buffer) int + String() string + GetInstructionIndex() int + GetIndex() int + GetText() string + GetOpName() string + GetTokens() TokenStream + SetInstructionIndex(val int) + SetIndex(int) + SetText(string) + SetOpName(string) + SetTokens(TokenStream) +} + +type BaseRewriteOperation struct { + //Current index of rewrites list + instruction_index int + //Token buffer index + index int + //Substitution text + text string + //Actual operation name + op_name string + //Pointer to token steam + tokens TokenStream +} + +func (op *BaseRewriteOperation) GetInstructionIndex() int { + return op.instruction_index +} + +func (op *BaseRewriteOperation) GetIndex() int { + return op.index +} + +func (op *BaseRewriteOperation) GetText() string { + return op.text +} + +func (op *BaseRewriteOperation) GetOpName() string { + return op.op_name +} + +func (op *BaseRewriteOperation) GetTokens() TokenStream { + return op.tokens +} + +func (op *BaseRewriteOperation) SetInstructionIndex(val int) { + op.instruction_index = val +} + +func (op *BaseRewriteOperation) SetIndex(val int) { + op.index = val +} + +func (op *BaseRewriteOperation) SetText(val string) { + op.text = val +} + +func (op *BaseRewriteOperation) SetOpName(val string) { + op.op_name = val +} + +func (op *BaseRewriteOperation) SetTokens(val TokenStream) { + op.tokens = val +} + +func (op *BaseRewriteOperation) Execute(buffer *bytes.Buffer) int { + return op.index +} + +func (op *BaseRewriteOperation) String() string { + return fmt.Sprintf("<%s@%d:\"%s\">", + op.op_name, + op.tokens.Get(op.GetIndex()), + op.text, + ) + +} + +type InsertBeforeOp struct { + BaseRewriteOperation +} + +func NewInsertBeforeOp(index int, text string, stream TokenStream) *InsertBeforeOp { + return &InsertBeforeOp{BaseRewriteOperation: BaseRewriteOperation{ + index: index, + text: text, + op_name: "InsertBeforeOp", + tokens: stream, + }} +} + +func (op *InsertBeforeOp) Execute(buffer *bytes.Buffer) int { + buffer.WriteString(op.text) + if op.tokens.Get(op.index).GetTokenType() != TokenEOF { + buffer.WriteString(op.tokens.Get(op.index).GetText()) + } + return op.index + 1 +} + +func (op *InsertBeforeOp) String() string { + return op.BaseRewriteOperation.String() +} + +// Distinguish between insert after/before to do the "insert afters" +// first and then the "insert befores" at same index. Implementation +// of "insert after" is "insert before index+1". + +type InsertAfterOp struct { + BaseRewriteOperation +} + +func NewInsertAfterOp(index int, text string, stream TokenStream) *InsertAfterOp { + return &InsertAfterOp{BaseRewriteOperation: BaseRewriteOperation{ + index: index + 1, + text: text, + tokens: stream, + }} +} + +func (op *InsertAfterOp) Execute(buffer *bytes.Buffer) int { + buffer.WriteString(op.text) + if op.tokens.Get(op.index).GetTokenType() != TokenEOF { + buffer.WriteString(op.tokens.Get(op.index).GetText()) + } + return op.index + 1 +} + +func (op *InsertAfterOp) String() string { + return op.BaseRewriteOperation.String() +} + +// I'm going to try replacing range from x..y with (y-x)+1 ReplaceOp +// instructions. +type ReplaceOp struct { + BaseRewriteOperation + LastIndex int +} + +func NewReplaceOp(from, to int, text string, stream TokenStream) *ReplaceOp { + return &ReplaceOp{ + BaseRewriteOperation: BaseRewriteOperation{ + index: from, + text: text, + op_name: "ReplaceOp", + tokens: stream, + }, + LastIndex: to, + } +} + +func (op *ReplaceOp) Execute(buffer *bytes.Buffer) int { + if op.text != "" { + buffer.WriteString(op.text) + } + return op.LastIndex + 1 +} + +func (op *ReplaceOp) String() string { + if op.text == "" { + return fmt.Sprintf("This is a one way link. It emanates from a state (usually via a list of -// transitions) and has a target state.
-// -//Since we never have to change the ATN transitions once we construct it, -// the states. We'll use the term Edge for the DFA to distinguish them from -// ATN transitions.
- -type Transition interface { - getTarget() ATNState - setTarget(ATNState) - getIsEpsilon() bool - getLabel() *IntervalSet - getSerializationType() int - Matches(int, int, int) bool -} - -type BaseTransition struct { - target ATNState - isEpsilon bool - label int - intervalSet *IntervalSet - serializationType int -} - -func NewBaseTransition(target ATNState) *BaseTransition { - - if target == nil { - panic("target cannot be nil.") - } - - t := new(BaseTransition) - - t.target = target - // Are we epsilon, action, sempred? - t.isEpsilon = false - t.intervalSet = nil - - return t -} - -func (t *BaseTransition) getTarget() ATNState { - return t.target -} - -func (t *BaseTransition) setTarget(s ATNState) { - t.target = s -} - -func (t *BaseTransition) getIsEpsilon() bool { - return t.isEpsilon -} - -func (t *BaseTransition) getLabel() *IntervalSet { - return t.intervalSet -} - -func (t *BaseTransition) getSerializationType() int { - return t.serializationType -} - -func (t *BaseTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - panic("Not implemented") -} - -const ( - TransitionEPSILON = 1 - TransitionRANGE = 2 - TransitionRULE = 3 - TransitionPREDICATE = 4 // e.g., {isType(input.LT(1))}? - TransitionATOM = 5 - TransitionACTION = 6 - TransitionSET = 7 // ~(A|B) or ~atom, wildcard, which convert to next 2 - TransitionNOTSET = 8 - TransitionWILDCARD = 9 - TransitionPRECEDENCE = 10 -) - -var TransitionserializationNames = []string{ - "INVALID", - "EPSILON", - "RANGE", - "RULE", - "PREDICATE", - "ATOM", - "ACTION", - "SET", - "NOT_SET", - "WILDCARD", - "PRECEDENCE", -} - -//var TransitionserializationTypes struct { -// EpsilonTransition int -// RangeTransition int -// RuleTransition int -// PredicateTransition int -// AtomTransition int -// ActionTransition int -// SetTransition int -// NotSetTransition int -// WildcardTransition int -// PrecedencePredicateTransition int -//}{ -// TransitionEPSILON, -// TransitionRANGE, -// TransitionRULE, -// TransitionPREDICATE, -// TransitionATOM, -// TransitionACTION, -// TransitionSET, -// TransitionNOTSET, -// TransitionWILDCARD, -// TransitionPRECEDENCE -//} - -// TODO: make all transitions sets? no, should remove set edges -type AtomTransition struct { - *BaseTransition -} - -func NewAtomTransition(target ATNState, intervalSet int) *AtomTransition { - - t := new(AtomTransition) - t.BaseTransition = NewBaseTransition(target) - - t.label = intervalSet // The token type or character value or, signifies special intervalSet. - t.intervalSet = t.makeLabel() - t.serializationType = TransitionATOM - - return t -} - -func (t *AtomTransition) makeLabel() *IntervalSet { - s := NewIntervalSet() - s.addOne(t.label) - return s -} - -func (t *AtomTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return t.label == symbol -} - -func (t *AtomTransition) String() string { - return strconv.Itoa(t.label) -} - -type RuleTransition struct { - *BaseTransition - - followState ATNState - ruleIndex, precedence int -} - -func NewRuleTransition(ruleStart ATNState, ruleIndex, precedence int, followState ATNState) *RuleTransition { - - t := new(RuleTransition) - t.BaseTransition = NewBaseTransition(ruleStart) - - t.ruleIndex = ruleIndex - t.precedence = precedence - t.followState = followState - t.serializationType = TransitionRULE - t.isEpsilon = true - - return t -} - -func (t *RuleTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return false -} - -type EpsilonTransition struct { - *BaseTransition - - outermostPrecedenceReturn int -} - -func NewEpsilonTransition(target ATNState, outermostPrecedenceReturn int) *EpsilonTransition { - - t := new(EpsilonTransition) - t.BaseTransition = NewBaseTransition(target) - - t.serializationType = TransitionEPSILON - t.isEpsilon = true - t.outermostPrecedenceReturn = outermostPrecedenceReturn - return t -} - -func (t *EpsilonTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return false -} - -func (t *EpsilonTransition) String() string { - return "epsilon" -} - -type RangeTransition struct { - *BaseTransition - - start, stop int -} - -func NewRangeTransition(target ATNState, start, stop int) *RangeTransition { - - t := new(RangeTransition) - t.BaseTransition = NewBaseTransition(target) - - t.serializationType = TransitionRANGE - t.start = start - t.stop = stop - t.intervalSet = t.makeLabel() - return t -} - -func (t *RangeTransition) makeLabel() *IntervalSet { - s := NewIntervalSet() - s.addRange(t.start, t.stop) - return s -} - -func (t *RangeTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return symbol >= t.start && symbol <= t.stop -} - -func (t *RangeTransition) String() string { - var sb strings.Builder - sb.WriteByte('\'') - sb.WriteRune(rune(t.start)) - sb.WriteString("'..'") - sb.WriteRune(rune(t.stop)) - sb.WriteByte('\'') - return sb.String() -} - -type AbstractPredicateTransition interface { - Transition - IAbstractPredicateTransitionFoo() -} - -type BaseAbstractPredicateTransition struct { - *BaseTransition -} - -func NewBasePredicateTransition(target ATNState) *BaseAbstractPredicateTransition { - - t := new(BaseAbstractPredicateTransition) - t.BaseTransition = NewBaseTransition(target) - - return t -} - -func (a *BaseAbstractPredicateTransition) IAbstractPredicateTransitionFoo() {} - -type PredicateTransition struct { - *BaseAbstractPredicateTransition - - isCtxDependent bool - ruleIndex, predIndex int -} - -func NewPredicateTransition(target ATNState, ruleIndex, predIndex int, isCtxDependent bool) *PredicateTransition { - - t := new(PredicateTransition) - t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target) - - t.serializationType = TransitionPREDICATE - t.ruleIndex = ruleIndex - t.predIndex = predIndex - t.isCtxDependent = isCtxDependent // e.g., $i ref in pred - t.isEpsilon = true - return t -} - -func (t *PredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return false -} - -func (t *PredicateTransition) getPredicate() *Predicate { - return NewPredicate(t.ruleIndex, t.predIndex, t.isCtxDependent) -} - -func (t *PredicateTransition) String() string { - return "pred_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.predIndex) -} - -type ActionTransition struct { - *BaseTransition - - isCtxDependent bool - ruleIndex, actionIndex, predIndex int -} - -func NewActionTransition(target ATNState, ruleIndex, actionIndex int, isCtxDependent bool) *ActionTransition { - - t := new(ActionTransition) - t.BaseTransition = NewBaseTransition(target) - - t.serializationType = TransitionACTION - t.ruleIndex = ruleIndex - t.actionIndex = actionIndex - t.isCtxDependent = isCtxDependent // e.g., $i ref in pred - t.isEpsilon = true - return t -} - -func (t *ActionTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return false -} - -func (t *ActionTransition) String() string { - return "action_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.actionIndex) -} - -type SetTransition struct { - *BaseTransition -} - -func NewSetTransition(target ATNState, set *IntervalSet) *SetTransition { - - t := new(SetTransition) - t.BaseTransition = NewBaseTransition(target) - - t.serializationType = TransitionSET - if set != nil { - t.intervalSet = set - } else { - t.intervalSet = NewIntervalSet() - t.intervalSet.addOne(TokenInvalidType) - } - - return t -} - -func (t *SetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return t.intervalSet.contains(symbol) -} - -func (t *SetTransition) String() string { - return t.intervalSet.String() -} - -type NotSetTransition struct { - *SetTransition -} - -func NewNotSetTransition(target ATNState, set *IntervalSet) *NotSetTransition { - - t := new(NotSetTransition) - - t.SetTransition = NewSetTransition(target, set) - - t.serializationType = TransitionNOTSET - - return t -} - -func (t *NotSetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return symbol >= minVocabSymbol && symbol <= maxVocabSymbol && !t.intervalSet.contains(symbol) -} - -func (t *NotSetTransition) String() string { - return "~" + t.intervalSet.String() -} - -type WildcardTransition struct { - *BaseTransition -} - -func NewWildcardTransition(target ATNState) *WildcardTransition { - - t := new(WildcardTransition) - t.BaseTransition = NewBaseTransition(target) - - t.serializationType = TransitionWILDCARD - return t -} - -func (t *WildcardTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return symbol >= minVocabSymbol && symbol <= maxVocabSymbol -} - -func (t *WildcardTransition) String() string { - return "." -} - -type PrecedencePredicateTransition struct { - *BaseAbstractPredicateTransition - - precedence int -} - -func NewPrecedencePredicateTransition(target ATNState, precedence int) *PrecedencePredicateTransition { - - t := new(PrecedencePredicateTransition) - t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target) - - t.serializationType = TransitionPRECEDENCE - t.precedence = precedence - t.isEpsilon = true - - return t -} - -func (t *PrecedencePredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { - return false -} - -func (t *PrecedencePredicateTransition) getPredicate() *PrecedencePredicate { - return NewPrecedencePredicate(t.precedence) -} - -func (t *PrecedencePredicateTransition) String() string { - return fmt.Sprint(t.precedence) + " >= _p" -} +// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. +// Use of this file is governed by the BSD 3-clause license that +// can be found in the LICENSE.txt file in the project root. + +package antlr + +import ( + "fmt" + "strconv" + "strings" +) + +// atom, set, epsilon, action, predicate, rule transitions. +// +//This is a one way link. It emanates from a state (usually via a list of +// transitions) and has a target state.
+// +//Since we never have to change the ATN transitions once we construct it, +// the states. We'll use the term Edge for the DFA to distinguish them from +// ATN transitions.
+ +type Transition interface { + getTarget() ATNState + setTarget(ATNState) + getIsEpsilon() bool + getLabel() *IntervalSet + getSerializationType() int + Matches(int, int, int) bool +} + +type BaseTransition struct { + target ATNState + isEpsilon bool + label int + intervalSet *IntervalSet + serializationType int +} + +func NewBaseTransition(target ATNState) *BaseTransition { + + if target == nil { + panic("target cannot be nil.") + } + + t := new(BaseTransition) + + t.target = target + // Are we epsilon, action, sempred? + t.isEpsilon = false + t.intervalSet = nil + + return t +} + +func (t *BaseTransition) getTarget() ATNState { + return t.target +} + +func (t *BaseTransition) setTarget(s ATNState) { + t.target = s +} + +func (t *BaseTransition) getIsEpsilon() bool { + return t.isEpsilon +} + +func (t *BaseTransition) getLabel() *IntervalSet { + return t.intervalSet +} + +func (t *BaseTransition) getSerializationType() int { + return t.serializationType +} + +func (t *BaseTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + panic("Not implemented") +} + +const ( + TransitionEPSILON = 1 + TransitionRANGE = 2 + TransitionRULE = 3 + TransitionPREDICATE = 4 // e.g., {isType(input.LT(1))}? + TransitionATOM = 5 + TransitionACTION = 6 + TransitionSET = 7 // ~(A|B) or ~atom, wildcard, which convert to next 2 + TransitionNOTSET = 8 + TransitionWILDCARD = 9 + TransitionPRECEDENCE = 10 +) + +var TransitionserializationNames = []string{ + "INVALID", + "EPSILON", + "RANGE", + "RULE", + "PREDICATE", + "ATOM", + "ACTION", + "SET", + "NOT_SET", + "WILDCARD", + "PRECEDENCE", +} + +//var TransitionserializationTypes struct { +// EpsilonTransition int +// RangeTransition int +// RuleTransition int +// PredicateTransition int +// AtomTransition int +// ActionTransition int +// SetTransition int +// NotSetTransition int +// WildcardTransition int +// PrecedencePredicateTransition int +//}{ +// TransitionEPSILON, +// TransitionRANGE, +// TransitionRULE, +// TransitionPREDICATE, +// TransitionATOM, +// TransitionACTION, +// TransitionSET, +// TransitionNOTSET, +// TransitionWILDCARD, +// TransitionPRECEDENCE +//} + +// TODO: make all transitions sets? no, should remove set edges +type AtomTransition struct { + *BaseTransition +} + +func NewAtomTransition(target ATNState, intervalSet int) *AtomTransition { + + t := new(AtomTransition) + t.BaseTransition = NewBaseTransition(target) + + t.label = intervalSet // The token type or character value or, signifies special intervalSet. + t.intervalSet = t.makeLabel() + t.serializationType = TransitionATOM + + return t +} + +func (t *AtomTransition) makeLabel() *IntervalSet { + s := NewIntervalSet() + s.addOne(t.label) + return s +} + +func (t *AtomTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return t.label == symbol +} + +func (t *AtomTransition) String() string { + return strconv.Itoa(t.label) +} + +type RuleTransition struct { + *BaseTransition + + followState ATNState + ruleIndex, precedence int +} + +func NewRuleTransition(ruleStart ATNState, ruleIndex, precedence int, followState ATNState) *RuleTransition { + + t := new(RuleTransition) + t.BaseTransition = NewBaseTransition(ruleStart) + + t.ruleIndex = ruleIndex + t.precedence = precedence + t.followState = followState + t.serializationType = TransitionRULE + t.isEpsilon = true + + return t +} + +func (t *RuleTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return false +} + +type EpsilonTransition struct { + *BaseTransition + + outermostPrecedenceReturn int +} + +func NewEpsilonTransition(target ATNState, outermostPrecedenceReturn int) *EpsilonTransition { + + t := new(EpsilonTransition) + t.BaseTransition = NewBaseTransition(target) + + t.serializationType = TransitionEPSILON + t.isEpsilon = true + t.outermostPrecedenceReturn = outermostPrecedenceReturn + return t +} + +func (t *EpsilonTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return false +} + +func (t *EpsilonTransition) String() string { + return "epsilon" +} + +type RangeTransition struct { + *BaseTransition + + start, stop int +} + +func NewRangeTransition(target ATNState, start, stop int) *RangeTransition { + + t := new(RangeTransition) + t.BaseTransition = NewBaseTransition(target) + + t.serializationType = TransitionRANGE + t.start = start + t.stop = stop + t.intervalSet = t.makeLabel() + return t +} + +func (t *RangeTransition) makeLabel() *IntervalSet { + s := NewIntervalSet() + s.addRange(t.start, t.stop) + return s +} + +func (t *RangeTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return symbol >= t.start && symbol <= t.stop +} + +func (t *RangeTransition) String() string { + var sb strings.Builder + sb.WriteByte('\'') + sb.WriteRune(rune(t.start)) + sb.WriteString("'..'") + sb.WriteRune(rune(t.stop)) + sb.WriteByte('\'') + return sb.String() +} + +type AbstractPredicateTransition interface { + Transition + IAbstractPredicateTransitionFoo() +} + +type BaseAbstractPredicateTransition struct { + *BaseTransition +} + +func NewBasePredicateTransition(target ATNState) *BaseAbstractPredicateTransition { + + t := new(BaseAbstractPredicateTransition) + t.BaseTransition = NewBaseTransition(target) + + return t +} + +func (a *BaseAbstractPredicateTransition) IAbstractPredicateTransitionFoo() {} + +type PredicateTransition struct { + *BaseAbstractPredicateTransition + + isCtxDependent bool + ruleIndex, predIndex int +} + +func NewPredicateTransition(target ATNState, ruleIndex, predIndex int, isCtxDependent bool) *PredicateTransition { + + t := new(PredicateTransition) + t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target) + + t.serializationType = TransitionPREDICATE + t.ruleIndex = ruleIndex + t.predIndex = predIndex + t.isCtxDependent = isCtxDependent // e.g., $i ref in pred + t.isEpsilon = true + return t +} + +func (t *PredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return false +} + +func (t *PredicateTransition) getPredicate() *Predicate { + return NewPredicate(t.ruleIndex, t.predIndex, t.isCtxDependent) +} + +func (t *PredicateTransition) String() string { + return "pred_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.predIndex) +} + +type ActionTransition struct { + *BaseTransition + + isCtxDependent bool + ruleIndex, actionIndex, predIndex int +} + +func NewActionTransition(target ATNState, ruleIndex, actionIndex int, isCtxDependent bool) *ActionTransition { + + t := new(ActionTransition) + t.BaseTransition = NewBaseTransition(target) + + t.serializationType = TransitionACTION + t.ruleIndex = ruleIndex + t.actionIndex = actionIndex + t.isCtxDependent = isCtxDependent // e.g., $i ref in pred + t.isEpsilon = true + return t +} + +func (t *ActionTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return false +} + +func (t *ActionTransition) String() string { + return "action_" + strconv.Itoa(t.ruleIndex) + ":" + strconv.Itoa(t.actionIndex) +} + +type SetTransition struct { + *BaseTransition +} + +func NewSetTransition(target ATNState, set *IntervalSet) *SetTransition { + + t := new(SetTransition) + t.BaseTransition = NewBaseTransition(target) + + t.serializationType = TransitionSET + if set != nil { + t.intervalSet = set + } else { + t.intervalSet = NewIntervalSet() + t.intervalSet.addOne(TokenInvalidType) + } + + return t +} + +func (t *SetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return t.intervalSet.contains(symbol) +} + +func (t *SetTransition) String() string { + return t.intervalSet.String() +} + +type NotSetTransition struct { + *SetTransition +} + +func NewNotSetTransition(target ATNState, set *IntervalSet) *NotSetTransition { + + t := new(NotSetTransition) + + t.SetTransition = NewSetTransition(target, set) + + t.serializationType = TransitionNOTSET + + return t +} + +func (t *NotSetTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return symbol >= minVocabSymbol && symbol <= maxVocabSymbol && !t.intervalSet.contains(symbol) +} + +func (t *NotSetTransition) String() string { + return "~" + t.intervalSet.String() +} + +type WildcardTransition struct { + *BaseTransition +} + +func NewWildcardTransition(target ATNState) *WildcardTransition { + + t := new(WildcardTransition) + t.BaseTransition = NewBaseTransition(target) + + t.serializationType = TransitionWILDCARD + return t +} + +func (t *WildcardTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return symbol >= minVocabSymbol && symbol <= maxVocabSymbol +} + +func (t *WildcardTransition) String() string { + return "." +} + +type PrecedencePredicateTransition struct { + *BaseAbstractPredicateTransition + + precedence int +} + +func NewPrecedencePredicateTransition(target ATNState, precedence int) *PrecedencePredicateTransition { + + t := new(PrecedencePredicateTransition) + t.BaseAbstractPredicateTransition = NewBasePredicateTransition(target) + + t.serializationType = TransitionPRECEDENCE + t.precedence = precedence + t.isEpsilon = true + + return t +} + +func (t *PrecedencePredicateTransition) Matches(symbol, minVocabSymbol, maxVocabSymbol int) bool { + return false +} + +func (t *PrecedencePredicateTransition) getPredicate() *PrecedencePredicate { + return NewPrecedencePredicate(t.precedence) +} + +func (t *PrecedencePredicateTransition) String() string { + return fmt.Sprint(t.precedence) + " >= _p" +} diff --git a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/tree.go b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/tree.go index 85b4f137b5..7b6ace613d 100644 --- a/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/tree.go +++ b/vendor/github.com/antlr/antlr4/runtime/Go/antlr/v4/tree.go @@ -1,253 +1,253 @@ -// Copyright (c) 2012-2022 The ANTLR Project. All rights reserved. -// Use of this file is governed by the BSD 3-clause license that -// can be found in the LICENSE.txt file in the project root. - -package antlr - -// The basic notion of a tree has a parent, a payload, and a list of children. -// It is the most abstract interface for all the trees used by ANTLR. -/// - -var TreeInvalidInterval = NewInterval(-1, -2) - -type Tree interface { - GetParent() Tree - SetParent(Tree) - GetPayload() interface{} - GetChild(i int) Tree - GetChildCount() int - GetChildren() []Tree -} - -type SyntaxTree interface { - Tree - - GetSourceInterval() *Interval -} - -type ParseTree interface { - SyntaxTree - - Accept(Visitor ParseTreeVisitor) interface{} - GetText() string - - ToStringTree([]string, Recognizer) string -} - -type RuleNode interface { - ParseTree - - GetRuleContext() RuleContext - GetBaseRuleContext() *BaseRuleContext -} - -type TerminalNode interface { - ParseTree - - GetSymbol() Token -} - -type ErrorNode interface { - TerminalNode - - errorNode() -} - -type ParseTreeVisitor interface { - Visit(tree ParseTree) interface{} - VisitChildren(node RuleNode) interface{} - VisitTerminal(node TerminalNode) interface{} - VisitErrorNode(node ErrorNode) interface{} -} - -type BaseParseTreeVisitor struct{} - -var _ ParseTreeVisitor = &BaseParseTreeVisitor{} - -func (v *BaseParseTreeVisitor) Visit(tree ParseTree) interface{} { return tree.Accept(v) } -func (v *BaseParseTreeVisitor) VisitChildren(node RuleNode) interface{} { return nil } -func (v *BaseParseTreeVisitor) VisitTerminal(node TerminalNode) interface{} { return nil } -func (v *BaseParseTreeVisitor) VisitErrorNode(node ErrorNode) interface{} { return nil } - -// TODO -//func (this ParseTreeVisitor) Visit(ctx) { -// if (Utils.isArray(ctx)) { -// self := this -// return ctx.map(function(child) { return VisitAtom(self, child)}) -// } else { -// return VisitAtom(this, ctx) -// } -//} -// -//func VisitAtom(Visitor, ctx) { -// if (ctx.parser == nil) { //is terminal -// return -// } -// -// name := ctx.parser.ruleNames[ctx.ruleIndex] -// funcName := "Visit" + Utils.titleCase(name) -// -// return Visitor[funcName](ctx) -//} - -type ParseTreeListener interface { - VisitTerminal(node TerminalNode) - VisitErrorNode(node ErrorNode) - EnterEveryRule(ctx ParserRuleContext) - ExitEveryRule(ctx ParserRuleContext) -} - -type BaseParseTreeListener struct{} - -var _ ParseTreeListener = &BaseParseTreeListener{} - -func (l *BaseParseTreeListener) VisitTerminal(node TerminalNode) {} -func (l *BaseParseTreeListener) VisitErrorNode(node ErrorNode) {} -func (l *BaseParseTreeListener) EnterEveryRule(ctx ParserRuleContext) {} -func (l *BaseParseTreeListener) ExitEveryRule(ctx ParserRuleContext) {} - -type TerminalNodeImpl struct { - parentCtx RuleContext - - symbol Token -} - -var _ TerminalNode = &TerminalNodeImpl{} - -func NewTerminalNodeImpl(symbol Token) *TerminalNodeImpl { - tn := new(TerminalNodeImpl) - - tn.parentCtx = nil - tn.symbol = symbol - - return tn -} - -func (t *TerminalNodeImpl) GetChild(i int) Tree { - return nil -} - -func (t *TerminalNodeImpl) GetChildren() []Tree { - return nil -} - -func (t *TerminalNodeImpl) SetChildren(tree []Tree) { - panic("Cannot set children on terminal node") -} - -func (t *TerminalNodeImpl) GetSymbol() Token { - return t.symbol -} - -func (t *TerminalNodeImpl) GetParent() Tree { - return t.parentCtx -} - -func (t *TerminalNodeImpl) SetParent(tree Tree) { - t.parentCtx = tree.(RuleContext) -} - -func (t *TerminalNodeImpl) GetPayload() interface{} { - return t.symbol -} - -func (t *TerminalNodeImpl) GetSourceInterval() *Interval { - if t.symbol == nil { - return TreeInvalidInterval - } - tokenIndex := t.symbol.GetTokenIndex() - return NewInterval(tokenIndex, tokenIndex) -} - -func (t *TerminalNodeImpl) GetChildCount() int { - return 0 -} - -func (t *TerminalNodeImpl) Accept(v ParseTreeVisitor) interface{} { - return v.VisitTerminal(t) -} - -func (t *TerminalNodeImpl) GetText() string { - return t.symbol.GetText() -} - -func (t *TerminalNodeImpl) String() string { - if t.symbol.GetTokenType() == TokenEOF { - return "
-
-
-[![GoDoc Widget]][GoDoc] [![Travis Widget]][Travis]
-
-`chi` is a lightweight, idiomatic and composable router for building Go HTTP services. It's
-especially good at helping you write large REST API services that are kept maintainable as your
-project grows and changes. `chi` is built on the new `context` package introduced in Go 1.7 to
-handle signaling, cancelation and request-scoped values across a handler chain.
-
-The focus of the project has been to seek out an elegant and comfortable design for writing
-REST API servers, written during the development of the Pressly API service that powers our
-public API service, which in turn powers all of our client-side applications.
-
-The key considerations of chi's design are: project structure, maintainability, standard http
-handlers (stdlib-only), developer productivity, and deconstructing a large system into many small
-parts. The core router `github.com/go-chi/chi` is quite small (less than 1000 LOC), but we've also
-included some useful/optional subpackages: [middleware](/middleware), [render](https://github.com/go-chi/render)
-and [docgen](https://github.com/go-chi/docgen). We hope you enjoy it too!
-
-## Install
-
-`go get -u github.com/go-chi/chi`
-
-
-## Features
-
-* **Lightweight** - cloc'd in ~1000 LOC for the chi router
-* **Fast** - yes, see [benchmarks](#benchmarks)
-* **100% compatible with net/http** - use any http or middleware pkg in the ecosystem that is also compatible with `net/http`
-* **Designed for modular/composable APIs** - middlewares, inline middlewares, route groups and sub-router mounting
-* **Context control** - built on new `context` package, providing value chaining, cancellations and timeouts
-* **Robust** - in production at Pressly, CloudFlare, Heroku, 99Designs, and many others (see [discussion](https://github.com/go-chi/chi/issues/91))
-* **Doc generation** - `docgen` auto-generates routing documentation from your source to JSON or Markdown
-* **Go.mod support** - v1.x of chi (starting from v1.5.0), now has go.mod support (see [CHANGELOG](https://github.com/go-chi/chi/blob/master/CHANGELOG.md#v150-2020-11-12---now-with-gomod-support))
-* **No external dependencies** - plain ol' Go stdlib + net/http
-
-
-## Examples
-
-See [_examples/](https://github.com/go-chi/chi/blob/master/_examples/) for a variety of examples.
-
-
-**As easy as:**
-
-```go
-package main
-
-import (
- "net/http"
-
- "github.com/go-chi/chi"
- "github.com/go-chi/chi/middleware"
-)
-
-func main() {
- r := chi.NewRouter()
- r.Use(middleware.Logger)
- r.Get("/", func(w http.ResponseWriter, r *http.Request) {
- w.Write([]byte("welcome"))
- })
- http.ListenAndServe(":3000", r)
-}
-```
-
-**REST Preview:**
-
-Here is a little preview of how routing looks like with chi. Also take a look at the generated routing docs
-in JSON ([routes.json](https://github.com/go-chi/chi/blob/master/_examples/rest/routes.json)) and in
-Markdown ([routes.md](https://github.com/go-chi/chi/blob/master/_examples/rest/routes.md)).
-
-I highly recommend reading the source of the [examples](https://github.com/go-chi/chi/blob/master/_examples/) listed
-above, they will show you all the features of chi and serve as a good form of documentation.
-
-```go
-import (
- //...
- "context"
- "github.com/go-chi/chi"
- "github.com/go-chi/chi/middleware"
-)
-
-func main() {
- r := chi.NewRouter()
-
- // A good base middleware stack
- r.Use(middleware.RequestID)
- r.Use(middleware.RealIP)
- r.Use(middleware.Logger)
- r.Use(middleware.Recoverer)
-
- // Set a timeout value on the request context (ctx), that will signal
- // through ctx.Done() that the request has timed out and further
- // processing should be stopped.
- r.Use(middleware.Timeout(60 * time.Second))
-
- r.Get("/", func(w http.ResponseWriter, r *http.Request) {
- w.Write([]byte("hi"))
- })
-
- // RESTy routes for "articles" resource
- r.Route("/articles", func(r chi.Router) {
- r.With(paginate).Get("/", listArticles) // GET /articles
- r.With(paginate).Get("/{month}-{day}-{year}", listArticlesByDate) // GET /articles/01-16-2017
-
- r.Post("/", createArticle) // POST /articles
- r.Get("/search", searchArticles) // GET /articles/search
-
- // Regexp url parameters:
- r.Get("/{articleSlug:[a-z-]+}", getArticleBySlug) // GET /articles/home-is-toronto
-
- // Subrouters:
- r.Route("/{articleID}", func(r chi.Router) {
- r.Use(ArticleCtx)
- r.Get("/", getArticle) // GET /articles/123
- r.Put("/", updateArticle) // PUT /articles/123
- r.Delete("/", deleteArticle) // DELETE /articles/123
- })
- })
-
- // Mount the admin sub-router
- r.Mount("/admin", adminRouter())
-
- http.ListenAndServe(":3333", r)
-}
-
-func ArticleCtx(next http.Handler) http.Handler {
- return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
- articleID := chi.URLParam(r, "articleID")
- article, err := dbGetArticle(articleID)
- if err != nil {
- http.Error(w, http.StatusText(404), 404)
- return
- }
- ctx := context.WithValue(r.Context(), "article", article)
- next.ServeHTTP(w, r.WithContext(ctx))
- })
-}
-
-func getArticle(w http.ResponseWriter, r *http.Request) {
- ctx := r.Context()
- article, ok := ctx.Value("article").(*Article)
- if !ok {
- http.Error(w, http.StatusText(422), 422)
- return
- }
- w.Write([]byte(fmt.Sprintf("title:%s", article.Title)))
-}
-
-// A completely separate router for administrator routes
-func adminRouter() http.Handler {
- r := chi.NewRouter()
- r.Use(AdminOnly)
- r.Get("/", adminIndex)
- r.Get("/accounts", adminListAccounts)
- return r
-}
-
-func AdminOnly(next http.Handler) http.Handler {
- return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
- ctx := r.Context()
- perm, ok := ctx.Value("acl.permission").(YourPermissionType)
- if !ok || !perm.IsAdmin() {
- http.Error(w, http.StatusText(403), 403)
- return
- }
- next.ServeHTTP(w, r)
- })
-}
-```
-
-
-## Router interface
-
-chi's router is based on a kind of [Patricia Radix trie](https://en.wikipedia.org/wiki/Radix_tree).
-The router is fully compatible with `net/http`.
-
-Built on top of the tree is the `Router` interface:
-
-```go
-// Router consisting of the core routing methods used by chi's Mux,
-// using only the standard net/http.
-type Router interface {
- http.Handler
- Routes
-
- // Use appends one or more middlewares onto the Router stack.
- Use(middlewares ...func(http.Handler) http.Handler)
-
- // With adds inline middlewares for an endpoint handler.
- With(middlewares ...func(http.Handler) http.Handler) Router
-
- // Group adds a new inline-Router along the current routing
- // path, with a fresh middleware stack for the inline-Router.
- Group(fn func(r Router)) Router
-
- // Route mounts a sub-Router along a `pattern`` string.
- Route(pattern string, fn func(r Router)) Router
-
- // Mount attaches another http.Handler along ./pattern/*
- Mount(pattern string, h http.Handler)
-
- // Handle and HandleFunc adds routes for `pattern` that matches
- // all HTTP methods.
- Handle(pattern string, h http.Handler)
- HandleFunc(pattern string, h http.HandlerFunc)
-
- // Method and MethodFunc adds routes for `pattern` that matches
- // the `method` HTTP method.
- Method(method, pattern string, h http.Handler)
- MethodFunc(method, pattern string, h http.HandlerFunc)
-
- // HTTP-method routing along `pattern`
- Connect(pattern string, h http.HandlerFunc)
- Delete(pattern string, h http.HandlerFunc)
- Get(pattern string, h http.HandlerFunc)
- Head(pattern string, h http.HandlerFunc)
- Options(pattern string, h http.HandlerFunc)
- Patch(pattern string, h http.HandlerFunc)
- Post(pattern string, h http.HandlerFunc)
- Put(pattern string, h http.HandlerFunc)
- Trace(pattern string, h http.HandlerFunc)
-
- // NotFound defines a handler to respond whenever a route could
- // not be found.
- NotFound(h http.HandlerFunc)
-
- // MethodNotAllowed defines a handler to respond whenever a method is
- // not allowed.
- MethodNotAllowed(h http.HandlerFunc)
-}
-
-// Routes interface adds two methods for router traversal, which is also
-// used by the github.com/go-chi/docgen package to generate documentation for Routers.
-type Routes interface {
- // Routes returns the routing tree in an easily traversable structure.
- Routes() []Route
-
- // Middlewares returns the list of middlewares in use by the router.
- Middlewares() Middlewares
-
- // Match searches the routing tree for a handler that matches
- // the method/path - similar to routing a http request, but without
- // executing the handler thereafter.
- Match(rctx *Context, method, path string) bool
-}
-```
-
-Each routing method accepts a URL `pattern` and chain of `handlers`. The URL pattern
-supports named params (ie. `/users/{userID}`) and wildcards (ie. `/admin/*`). URL parameters
-can be fetched at runtime by calling `chi.URLParam(r, "userID")` for named parameters
-and `chi.URLParam(r, "*")` for a wildcard parameter.
-
-
-### Middleware handlers
-
-chi's middlewares are just stdlib net/http middleware handlers. There is nothing special
-about them, which means the router and all the tooling is designed to be compatible and
-friendly with any middleware in the community. This offers much better extensibility and reuse
-of packages and is at the heart of chi's purpose.
-
-Here is an example of a standard net/http middleware where we assign a context key `"user"`
-the value of `"123"`. This middleware sets a hypothetical user identifier on the request
-context and calls the next handler in the chain.
-
-```go
-// HTTP middleware setting a value on the request context
-func MyMiddleware(next http.Handler) http.Handler {
- return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
- // create new context from `r` request context, and assign key `"user"`
- // to value of `"123"`
- ctx := context.WithValue(r.Context(), "user", "123")
-
- // call the next handler in the chain, passing the response writer and
- // the updated request object with the new context value.
- //
- // note: context.Context values are nested, so any previously set
- // values will be accessible as well, and the new `"user"` key
- // will be accessible from this point forward.
- next.ServeHTTP(w, r.WithContext(ctx))
- })
-}
-```
-
-
-### Request handlers
-
-chi uses standard net/http request handlers. This little snippet is an example of a http.Handler
-func that reads a user identifier from the request context - hypothetically, identifying
-the user sending an authenticated request, validated+set by a previous middleware handler.
-
-```go
-// HTTP handler accessing data from the request context.
-func MyRequestHandler(w http.ResponseWriter, r *http.Request) {
- // here we read from the request context and fetch out `"user"` key set in
- // the MyMiddleware example above.
- user := r.Context().Value("user").(string)
-
- // respond to the client
- w.Write([]byte(fmt.Sprintf("hi %s", user)))
-}
-```
-
-
-### URL parameters
-
-chi's router parses and stores URL parameters right onto the request context. Here is
-an example of how to access URL params in your net/http handlers. And of course, middlewares
-are able to access the same information.
-
-```go
-// HTTP handler accessing the url routing parameters.
-func MyRequestHandler(w http.ResponseWriter, r *http.Request) {
- // fetch the url parameter `"userID"` from the request of a matching
- // routing pattern. An example routing pattern could be: /users/{userID}
- userID := chi.URLParam(r, "userID")
-
- // fetch `"key"` from the request context
- ctx := r.Context()
- key := ctx.Value("key").(string)
-
- // respond to the client
- w.Write([]byte(fmt.Sprintf("hi %v, %v", userID, key)))
-}
-```
-
-
-## Middlewares
-
-chi comes equipped with an optional `middleware` package, providing a suite of standard
-`net/http` middlewares. Please note, any middleware in the ecosystem that is also compatible
-with `net/http` can be used with chi's mux.
-
-### Core middlewares
-
-----------------------------------------------------------------------------------------------------
-| chi/middleware Handler | description |
-| :--------------------- | :---------------------------------------------------------------------- |
-| [AllowContentEncoding] | Enforces a whitelist of request Content-Encoding headers |
-| [AllowContentType] | Explicit whitelist of accepted request Content-Types |
-| [BasicAuth] | Basic HTTP authentication |
-| [Compress] | Gzip compression for clients that accept compressed responses |
-| [ContentCharset] | Ensure charset for Content-Type request headers |
-| [CleanPath] | Clean double slashes from request path |
-| [GetHead] | Automatically route undefined HEAD requests to GET handlers |
-| [Heartbeat] | Monitoring endpoint to check the servers pulse |
-| [Logger] | Logs the start and end of each request with the elapsed processing time |
-| [NoCache] | Sets response headers to prevent clients from caching |
-| [Profiler] | Easily attach net/http/pprof to your routers |
-| [RealIP] | Sets a http.Request's RemoteAddr to either X-Forwarded-For or X-Real-IP |
-| [Recoverer] | Gracefully absorb panics and prints the stack trace |
-| [RequestID] | Injects a request ID into the context of each request |
-| [RedirectSlashes] | Redirect slashes on routing paths |
-| [RouteHeaders] | Route handling for request headers |
-| [SetHeader] | Short-hand middleware to set a response header key/value |
-| [StripSlashes] | Strip slashes on routing paths |
-| [Throttle] | Puts a ceiling on the number of concurrent requests |
-| [Timeout] | Signals to the request context when the timeout deadline is reached |
-| [URLFormat] | Parse extension from url and put it on request context |
-| [WithValue] | Short-hand middleware to set a key/value on the request context |
-----------------------------------------------------------------------------------------------------
-
-[AllowContentEncoding]: https://pkg.go.dev/github.com/go-chi/chi/middleware#AllowContentEncoding
-[AllowContentType]: https://pkg.go.dev/github.com/go-chi/chi/middleware#AllowContentType
-[BasicAuth]: https://pkg.go.dev/github.com/go-chi/chi/middleware#BasicAuth
-[Compress]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Compress
-[ContentCharset]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ContentCharset
-[CleanPath]: https://pkg.go.dev/github.com/go-chi/chi/middleware#CleanPath
-[GetHead]: https://pkg.go.dev/github.com/go-chi/chi/middleware#GetHead
-[GetReqID]: https://pkg.go.dev/github.com/go-chi/chi/middleware#GetReqID
-[Heartbeat]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Heartbeat
-[Logger]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Logger
-[NoCache]: https://pkg.go.dev/github.com/go-chi/chi/middleware#NoCache
-[Profiler]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Profiler
-[RealIP]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RealIP
-[Recoverer]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Recoverer
-[RedirectSlashes]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RedirectSlashes
-[RequestLogger]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RequestLogger
-[RequestID]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RequestID
-[RouteHeaders]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RouteHeaders
-[SetHeader]: https://pkg.go.dev/github.com/go-chi/chi/middleware#SetHeader
-[StripSlashes]: https://pkg.go.dev/github.com/go-chi/chi/middleware#StripSlashes
-[Throttle]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Throttle
-[ThrottleBacklog]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ThrottleBacklog
-[ThrottleWithOpts]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ThrottleWithOpts
-[Timeout]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Timeout
-[URLFormat]: https://pkg.go.dev/github.com/go-chi/chi/middleware#URLFormat
-[WithLogEntry]: https://pkg.go.dev/github.com/go-chi/chi/middleware#WithLogEntry
-[WithValue]: https://pkg.go.dev/github.com/go-chi/chi/middleware#WithValue
-[Compressor]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Compressor
-[DefaultLogFormatter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#DefaultLogFormatter
-[EncoderFunc]: https://pkg.go.dev/github.com/go-chi/chi/middleware#EncoderFunc
-[HeaderRoute]: https://pkg.go.dev/github.com/go-chi/chi/middleware#HeaderRoute
-[HeaderRouter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#HeaderRouter
-[LogEntry]: https://pkg.go.dev/github.com/go-chi/chi/middleware#LogEntry
-[LogFormatter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#LogFormatter
-[LoggerInterface]: https://pkg.go.dev/github.com/go-chi/chi/middleware#LoggerInterface
-[ThrottleOpts]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ThrottleOpts
-[WrapResponseWriter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#WrapResponseWriter
-
-### Extra middlewares & packages
-
-Please see https://github.com/go-chi for additional packages.
-
---------------------------------------------------------------------------------------------------------------------
-| package | description |
-|:---------------------------------------------------|:-------------------------------------------------------------
-| [cors](https://github.com/go-chi/cors) | Cross-origin resource sharing (CORS) |
-| [docgen](https://github.com/go-chi/docgen) | Print chi.Router routes at runtime |
-| [jwtauth](https://github.com/go-chi/jwtauth) | JWT authentication |
-| [hostrouter](https://github.com/go-chi/hostrouter) | Domain/host based request routing |
-| [httplog](https://github.com/go-chi/httplog) | Small but powerful structured HTTP request logging |
-| [httprate](https://github.com/go-chi/httprate) | HTTP request rate limiter |
-| [httptracer](https://github.com/go-chi/httptracer) | HTTP request performance tracing library |
-| [httpvcr](https://github.com/go-chi/httpvcr) | Write deterministic tests for external sources |
-| [stampede](https://github.com/go-chi/stampede) | HTTP request coalescer |
---------------------------------------------------------------------------------------------------------------------
-
-
-## context?
-
-`context` is a tiny pkg that provides simple interface to signal context across call stacks
-and goroutines. It was originally written by [Sameer Ajmani](https://github.com/Sajmani)
-and is available in stdlib since go1.7.
-
-Learn more at https://blog.golang.org/context
-
-and..
-* Docs: https://golang.org/pkg/context
-* Source: https://github.com/golang/go/tree/master/src/context
-
-
-## Benchmarks
-
-The benchmark suite: https://github.com/pkieltyka/go-http-routing-benchmark
-
-Results as of Nov 29, 2020 with Go 1.15.5 on Linux AMD 3950x
-
-```shell
-BenchmarkChi_Param 3075895 384 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_Param5 2116603 566 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_Param20 964117 1227 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_ParamWrite 2863413 420 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_GithubStatic 3045488 395 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_GithubParam 2204115 540 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_GithubAll 10000 113811 ns/op 81203 B/op 406 allocs/op
-BenchmarkChi_GPlusStatic 3337485 359 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_GPlusParam 2825853 423 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_GPlus2Params 2471697 483 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_GPlusAll 194220 5950 ns/op 5200 B/op 26 allocs/op
-BenchmarkChi_ParseStatic 3365324 356 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_ParseParam 2976614 404 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_Parse2Params 2638084 439 ns/op 400 B/op 2 allocs/op
-BenchmarkChi_ParseAll 109567 11295 ns/op 10400 B/op 52 allocs/op
-BenchmarkChi_StaticAll 16846 71308 ns/op 62802 B/op 314 allocs/op
-```
-
-Comparison with other routers: https://gist.github.com/pkieltyka/123032f12052520aaccab752bd3e78cc
-
-NOTE: the allocs in the benchmark above are from the calls to http.Request's
-`WithContext(context.Context)` method that clones the http.Request, sets the `Context()`
-on the duplicated (alloc'd) request and returns it the new request object. This is just
-how setting context on a request in Go works.
-
-
-## Go module support & note on chi's versioning
-
-* Go.mod support means we reset our versioning starting from v1.5 (see [CHANGELOG](https://github.com/go-chi/chi/blob/master/CHANGELOG.md#v150-2020-11-12---now-with-gomod-support))
-* All older tags are preserved, are backwards-compatible and will "just work" as they
-* Brand new systems can run `go get -u github.com/go-chi/chi` as normal, or `go get -u github.com/go-chi/chi@latest`
-to install chi, which will install v1.x+ built with go.mod support, starting from v1.5.0.
-* For existing projects who want to upgrade to the latest go.mod version, run: `go get -u github.com/go-chi/chi@v1.5.0`,
-which will get you on the go.mod version line (as Go's mod cache may still remember v4.x).
-* Any breaking changes will bump a "minor" release and backwards-compatible improvements/fixes will bump a "tiny" release.
-
-
-## Credits
-
-* Carl Jackson for https://github.com/zenazn/goji
- * Parts of chi's thinking comes from goji, and chi's middleware package
- sources from goji.
-* Armon Dadgar for https://github.com/armon/go-radix
-* Contributions: [@VojtechVitek](https://github.com/VojtechVitek)
-
-We'll be more than happy to see [your contributions](./CONTRIBUTING.md)!
-
-
-## Beyond REST
-
-chi is just a http router that lets you decompose request handling into many smaller layers.
-Many companies use chi to write REST services for their public APIs. But, REST is just a convention
-for managing state via HTTP, and there's a lot of other pieces required to write a complete client-server
-system or network of microservices.
-
-Looking beyond REST, I also recommend some newer works in the field:
-* [webrpc](https://github.com/webrpc/webrpc) - Web-focused RPC client+server framework with code-gen
-* [gRPC](https://github.com/grpc/grpc-go) - Google's RPC framework via protobufs
-* [graphql](https://github.com/99designs/gqlgen) - Declarative query language
-* [NATS](https://nats.io) - lightweight pub-sub
-
-
-## License
-
-Copyright (c) 2015-present [Peter Kieltyka](https://github.com/pkieltyka)
-
-Licensed under [MIT License](./LICENSE)
-
-[GoDoc]: https://pkg.go.dev/github.com/go-chi/chi?tab=versions
-[GoDoc Widget]: https://godoc.org/github.com/go-chi/chi?status.svg
-[Travis]: https://travis-ci.org/go-chi/chi
-[Travis Widget]: https://travis-ci.org/go-chi/chi.svg?branch=master
+#
+
+
+[![GoDoc Widget]][GoDoc] [![Travis Widget]][Travis]
+
+`chi` is a lightweight, idiomatic and composable router for building Go HTTP services. It's
+especially good at helping you write large REST API services that are kept maintainable as your
+project grows and changes. `chi` is built on the new `context` package introduced in Go 1.7 to
+handle signaling, cancelation and request-scoped values across a handler chain.
+
+The focus of the project has been to seek out an elegant and comfortable design for writing
+REST API servers, written during the development of the Pressly API service that powers our
+public API service, which in turn powers all of our client-side applications.
+
+The key considerations of chi's design are: project structure, maintainability, standard http
+handlers (stdlib-only), developer productivity, and deconstructing a large system into many small
+parts. The core router `github.com/go-chi/chi` is quite small (less than 1000 LOC), but we've also
+included some useful/optional subpackages: [middleware](/middleware), [render](https://github.com/go-chi/render)
+and [docgen](https://github.com/go-chi/docgen). We hope you enjoy it too!
+
+## Install
+
+`go get -u github.com/go-chi/chi`
+
+
+## Features
+
+* **Lightweight** - cloc'd in ~1000 LOC for the chi router
+* **Fast** - yes, see [benchmarks](#benchmarks)
+* **100% compatible with net/http** - use any http or middleware pkg in the ecosystem that is also compatible with `net/http`
+* **Designed for modular/composable APIs** - middlewares, inline middlewares, route groups and sub-router mounting
+* **Context control** - built on new `context` package, providing value chaining, cancellations and timeouts
+* **Robust** - in production at Pressly, CloudFlare, Heroku, 99Designs, and many others (see [discussion](https://github.com/go-chi/chi/issues/91))
+* **Doc generation** - `docgen` auto-generates routing documentation from your source to JSON or Markdown
+* **Go.mod support** - v1.x of chi (starting from v1.5.0), now has go.mod support (see [CHANGELOG](https://github.com/go-chi/chi/blob/master/CHANGELOG.md#v150-2020-11-12---now-with-gomod-support))
+* **No external dependencies** - plain ol' Go stdlib + net/http
+
+
+## Examples
+
+See [_examples/](https://github.com/go-chi/chi/blob/master/_examples/) for a variety of examples.
+
+
+**As easy as:**
+
+```go
+package main
+
+import (
+ "net/http"
+
+ "github.com/go-chi/chi"
+ "github.com/go-chi/chi/middleware"
+)
+
+func main() {
+ r := chi.NewRouter()
+ r.Use(middleware.Logger)
+ r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+ w.Write([]byte("welcome"))
+ })
+ http.ListenAndServe(":3000", r)
+}
+```
+
+**REST Preview:**
+
+Here is a little preview of how routing looks like with chi. Also take a look at the generated routing docs
+in JSON ([routes.json](https://github.com/go-chi/chi/blob/master/_examples/rest/routes.json)) and in
+Markdown ([routes.md](https://github.com/go-chi/chi/blob/master/_examples/rest/routes.md)).
+
+I highly recommend reading the source of the [examples](https://github.com/go-chi/chi/blob/master/_examples/) listed
+above, they will show you all the features of chi and serve as a good form of documentation.
+
+```go
+import (
+ //...
+ "context"
+ "github.com/go-chi/chi"
+ "github.com/go-chi/chi/middleware"
+)
+
+func main() {
+ r := chi.NewRouter()
+
+ // A good base middleware stack
+ r.Use(middleware.RequestID)
+ r.Use(middleware.RealIP)
+ r.Use(middleware.Logger)
+ r.Use(middleware.Recoverer)
+
+ // Set a timeout value on the request context (ctx), that will signal
+ // through ctx.Done() that the request has timed out and further
+ // processing should be stopped.
+ r.Use(middleware.Timeout(60 * time.Second))
+
+ r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+ w.Write([]byte("hi"))
+ })
+
+ // RESTy routes for "articles" resource
+ r.Route("/articles", func(r chi.Router) {
+ r.With(paginate).Get("/", listArticles) // GET /articles
+ r.With(paginate).Get("/{month}-{day}-{year}", listArticlesByDate) // GET /articles/01-16-2017
+
+ r.Post("/", createArticle) // POST /articles
+ r.Get("/search", searchArticles) // GET /articles/search
+
+ // Regexp url parameters:
+ r.Get("/{articleSlug:[a-z-]+}", getArticleBySlug) // GET /articles/home-is-toronto
+
+ // Subrouters:
+ r.Route("/{articleID}", func(r chi.Router) {
+ r.Use(ArticleCtx)
+ r.Get("/", getArticle) // GET /articles/123
+ r.Put("/", updateArticle) // PUT /articles/123
+ r.Delete("/", deleteArticle) // DELETE /articles/123
+ })
+ })
+
+ // Mount the admin sub-router
+ r.Mount("/admin", adminRouter())
+
+ http.ListenAndServe(":3333", r)
+}
+
+func ArticleCtx(next http.Handler) http.Handler {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ articleID := chi.URLParam(r, "articleID")
+ article, err := dbGetArticle(articleID)
+ if err != nil {
+ http.Error(w, http.StatusText(404), 404)
+ return
+ }
+ ctx := context.WithValue(r.Context(), "article", article)
+ next.ServeHTTP(w, r.WithContext(ctx))
+ })
+}
+
+func getArticle(w http.ResponseWriter, r *http.Request) {
+ ctx := r.Context()
+ article, ok := ctx.Value("article").(*Article)
+ if !ok {
+ http.Error(w, http.StatusText(422), 422)
+ return
+ }
+ w.Write([]byte(fmt.Sprintf("title:%s", article.Title)))
+}
+
+// A completely separate router for administrator routes
+func adminRouter() http.Handler {
+ r := chi.NewRouter()
+ r.Use(AdminOnly)
+ r.Get("/", adminIndex)
+ r.Get("/accounts", adminListAccounts)
+ return r
+}
+
+func AdminOnly(next http.Handler) http.Handler {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ ctx := r.Context()
+ perm, ok := ctx.Value("acl.permission").(YourPermissionType)
+ if !ok || !perm.IsAdmin() {
+ http.Error(w, http.StatusText(403), 403)
+ return
+ }
+ next.ServeHTTP(w, r)
+ })
+}
+```
+
+
+## Router interface
+
+chi's router is based on a kind of [Patricia Radix trie](https://en.wikipedia.org/wiki/Radix_tree).
+The router is fully compatible with `net/http`.
+
+Built on top of the tree is the `Router` interface:
+
+```go
+// Router consisting of the core routing methods used by chi's Mux,
+// using only the standard net/http.
+type Router interface {
+ http.Handler
+ Routes
+
+ // Use appends one or more middlewares onto the Router stack.
+ Use(middlewares ...func(http.Handler) http.Handler)
+
+ // With adds inline middlewares for an endpoint handler.
+ With(middlewares ...func(http.Handler) http.Handler) Router
+
+ // Group adds a new inline-Router along the current routing
+ // path, with a fresh middleware stack for the inline-Router.
+ Group(fn func(r Router)) Router
+
+ // Route mounts a sub-Router along a `pattern`` string.
+ Route(pattern string, fn func(r Router)) Router
+
+ // Mount attaches another http.Handler along ./pattern/*
+ Mount(pattern string, h http.Handler)
+
+ // Handle and HandleFunc adds routes for `pattern` that matches
+ // all HTTP methods.
+ Handle(pattern string, h http.Handler)
+ HandleFunc(pattern string, h http.HandlerFunc)
+
+ // Method and MethodFunc adds routes for `pattern` that matches
+ // the `method` HTTP method.
+ Method(method, pattern string, h http.Handler)
+ MethodFunc(method, pattern string, h http.HandlerFunc)
+
+ // HTTP-method routing along `pattern`
+ Connect(pattern string, h http.HandlerFunc)
+ Delete(pattern string, h http.HandlerFunc)
+ Get(pattern string, h http.HandlerFunc)
+ Head(pattern string, h http.HandlerFunc)
+ Options(pattern string, h http.HandlerFunc)
+ Patch(pattern string, h http.HandlerFunc)
+ Post(pattern string, h http.HandlerFunc)
+ Put(pattern string, h http.HandlerFunc)
+ Trace(pattern string, h http.HandlerFunc)
+
+ // NotFound defines a handler to respond whenever a route could
+ // not be found.
+ NotFound(h http.HandlerFunc)
+
+ // MethodNotAllowed defines a handler to respond whenever a method is
+ // not allowed.
+ MethodNotAllowed(h http.HandlerFunc)
+}
+
+// Routes interface adds two methods for router traversal, which is also
+// used by the github.com/go-chi/docgen package to generate documentation for Routers.
+type Routes interface {
+ // Routes returns the routing tree in an easily traversable structure.
+ Routes() []Route
+
+ // Middlewares returns the list of middlewares in use by the router.
+ Middlewares() Middlewares
+
+ // Match searches the routing tree for a handler that matches
+ // the method/path - similar to routing a http request, but without
+ // executing the handler thereafter.
+ Match(rctx *Context, method, path string) bool
+}
+```
+
+Each routing method accepts a URL `pattern` and chain of `handlers`. The URL pattern
+supports named params (ie. `/users/{userID}`) and wildcards (ie. `/admin/*`). URL parameters
+can be fetched at runtime by calling `chi.URLParam(r, "userID")` for named parameters
+and `chi.URLParam(r, "*")` for a wildcard parameter.
+
+
+### Middleware handlers
+
+chi's middlewares are just stdlib net/http middleware handlers. There is nothing special
+about them, which means the router and all the tooling is designed to be compatible and
+friendly with any middleware in the community. This offers much better extensibility and reuse
+of packages and is at the heart of chi's purpose.
+
+Here is an example of a standard net/http middleware where we assign a context key `"user"`
+the value of `"123"`. This middleware sets a hypothetical user identifier on the request
+context and calls the next handler in the chain.
+
+```go
+// HTTP middleware setting a value on the request context
+func MyMiddleware(next http.Handler) http.Handler {
+ return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ // create new context from `r` request context, and assign key `"user"`
+ // to value of `"123"`
+ ctx := context.WithValue(r.Context(), "user", "123")
+
+ // call the next handler in the chain, passing the response writer and
+ // the updated request object with the new context value.
+ //
+ // note: context.Context values are nested, so any previously set
+ // values will be accessible as well, and the new `"user"` key
+ // will be accessible from this point forward.
+ next.ServeHTTP(w, r.WithContext(ctx))
+ })
+}
+```
+
+
+### Request handlers
+
+chi uses standard net/http request handlers. This little snippet is an example of a http.Handler
+func that reads a user identifier from the request context - hypothetically, identifying
+the user sending an authenticated request, validated+set by a previous middleware handler.
+
+```go
+// HTTP handler accessing data from the request context.
+func MyRequestHandler(w http.ResponseWriter, r *http.Request) {
+ // here we read from the request context and fetch out `"user"` key set in
+ // the MyMiddleware example above.
+ user := r.Context().Value("user").(string)
+
+ // respond to the client
+ w.Write([]byte(fmt.Sprintf("hi %s", user)))
+}
+```
+
+
+### URL parameters
+
+chi's router parses and stores URL parameters right onto the request context. Here is
+an example of how to access URL params in your net/http handlers. And of course, middlewares
+are able to access the same information.
+
+```go
+// HTTP handler accessing the url routing parameters.
+func MyRequestHandler(w http.ResponseWriter, r *http.Request) {
+ // fetch the url parameter `"userID"` from the request of a matching
+ // routing pattern. An example routing pattern could be: /users/{userID}
+ userID := chi.URLParam(r, "userID")
+
+ // fetch `"key"` from the request context
+ ctx := r.Context()
+ key := ctx.Value("key").(string)
+
+ // respond to the client
+ w.Write([]byte(fmt.Sprintf("hi %v, %v", userID, key)))
+}
+```
+
+
+## Middlewares
+
+chi comes equipped with an optional `middleware` package, providing a suite of standard
+`net/http` middlewares. Please note, any middleware in the ecosystem that is also compatible
+with `net/http` can be used with chi's mux.
+
+### Core middlewares
+
+----------------------------------------------------------------------------------------------------
+| chi/middleware Handler | description |
+| :--------------------- | :---------------------------------------------------------------------- |
+| [AllowContentEncoding] | Enforces a whitelist of request Content-Encoding headers |
+| [AllowContentType] | Explicit whitelist of accepted request Content-Types |
+| [BasicAuth] | Basic HTTP authentication |
+| [Compress] | Gzip compression for clients that accept compressed responses |
+| [ContentCharset] | Ensure charset for Content-Type request headers |
+| [CleanPath] | Clean double slashes from request path |
+| [GetHead] | Automatically route undefined HEAD requests to GET handlers |
+| [Heartbeat] | Monitoring endpoint to check the servers pulse |
+| [Logger] | Logs the start and end of each request with the elapsed processing time |
+| [NoCache] | Sets response headers to prevent clients from caching |
+| [Profiler] | Easily attach net/http/pprof to your routers |
+| [RealIP] | Sets a http.Request's RemoteAddr to either X-Forwarded-For or X-Real-IP |
+| [Recoverer] | Gracefully absorb panics and prints the stack trace |
+| [RequestID] | Injects a request ID into the context of each request |
+| [RedirectSlashes] | Redirect slashes on routing paths |
+| [RouteHeaders] | Route handling for request headers |
+| [SetHeader] | Short-hand middleware to set a response header key/value |
+| [StripSlashes] | Strip slashes on routing paths |
+| [Throttle] | Puts a ceiling on the number of concurrent requests |
+| [Timeout] | Signals to the request context when the timeout deadline is reached |
+| [URLFormat] | Parse extension from url and put it on request context |
+| [WithValue] | Short-hand middleware to set a key/value on the request context |
+----------------------------------------------------------------------------------------------------
+
+[AllowContentEncoding]: https://pkg.go.dev/github.com/go-chi/chi/middleware#AllowContentEncoding
+[AllowContentType]: https://pkg.go.dev/github.com/go-chi/chi/middleware#AllowContentType
+[BasicAuth]: https://pkg.go.dev/github.com/go-chi/chi/middleware#BasicAuth
+[Compress]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Compress
+[ContentCharset]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ContentCharset
+[CleanPath]: https://pkg.go.dev/github.com/go-chi/chi/middleware#CleanPath
+[GetHead]: https://pkg.go.dev/github.com/go-chi/chi/middleware#GetHead
+[GetReqID]: https://pkg.go.dev/github.com/go-chi/chi/middleware#GetReqID
+[Heartbeat]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Heartbeat
+[Logger]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Logger
+[NoCache]: https://pkg.go.dev/github.com/go-chi/chi/middleware#NoCache
+[Profiler]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Profiler
+[RealIP]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RealIP
+[Recoverer]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Recoverer
+[RedirectSlashes]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RedirectSlashes
+[RequestLogger]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RequestLogger
+[RequestID]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RequestID
+[RouteHeaders]: https://pkg.go.dev/github.com/go-chi/chi/middleware#RouteHeaders
+[SetHeader]: https://pkg.go.dev/github.com/go-chi/chi/middleware#SetHeader
+[StripSlashes]: https://pkg.go.dev/github.com/go-chi/chi/middleware#StripSlashes
+[Throttle]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Throttle
+[ThrottleBacklog]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ThrottleBacklog
+[ThrottleWithOpts]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ThrottleWithOpts
+[Timeout]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Timeout
+[URLFormat]: https://pkg.go.dev/github.com/go-chi/chi/middleware#URLFormat
+[WithLogEntry]: https://pkg.go.dev/github.com/go-chi/chi/middleware#WithLogEntry
+[WithValue]: https://pkg.go.dev/github.com/go-chi/chi/middleware#WithValue
+[Compressor]: https://pkg.go.dev/github.com/go-chi/chi/middleware#Compressor
+[DefaultLogFormatter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#DefaultLogFormatter
+[EncoderFunc]: https://pkg.go.dev/github.com/go-chi/chi/middleware#EncoderFunc
+[HeaderRoute]: https://pkg.go.dev/github.com/go-chi/chi/middleware#HeaderRoute
+[HeaderRouter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#HeaderRouter
+[LogEntry]: https://pkg.go.dev/github.com/go-chi/chi/middleware#LogEntry
+[LogFormatter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#LogFormatter
+[LoggerInterface]: https://pkg.go.dev/github.com/go-chi/chi/middleware#LoggerInterface
+[ThrottleOpts]: https://pkg.go.dev/github.com/go-chi/chi/middleware#ThrottleOpts
+[WrapResponseWriter]: https://pkg.go.dev/github.com/go-chi/chi/middleware#WrapResponseWriter
+
+### Extra middlewares & packages
+
+Please see https://github.com/go-chi for additional packages.
+
+--------------------------------------------------------------------------------------------------------------------
+| package | description |
+|:---------------------------------------------------|:-------------------------------------------------------------
+| [cors](https://github.com/go-chi/cors) | Cross-origin resource sharing (CORS) |
+| [docgen](https://github.com/go-chi/docgen) | Print chi.Router routes at runtime |
+| [jwtauth](https://github.com/go-chi/jwtauth) | JWT authentication |
+| [hostrouter](https://github.com/go-chi/hostrouter) | Domain/host based request routing |
+| [httplog](https://github.com/go-chi/httplog) | Small but powerful structured HTTP request logging |
+| [httprate](https://github.com/go-chi/httprate) | HTTP request rate limiter |
+| [httptracer](https://github.com/go-chi/httptracer) | HTTP request performance tracing library |
+| [httpvcr](https://github.com/go-chi/httpvcr) | Write deterministic tests for external sources |
+| [stampede](https://github.com/go-chi/stampede) | HTTP request coalescer |
+--------------------------------------------------------------------------------------------------------------------
+
+
+## context?
+
+`context` is a tiny pkg that provides simple interface to signal context across call stacks
+and goroutines. It was originally written by [Sameer Ajmani](https://github.com/Sajmani)
+and is available in stdlib since go1.7.
+
+Learn more at https://blog.golang.org/context
+
+and..
+* Docs: https://golang.org/pkg/context
+* Source: https://github.com/golang/go/tree/master/src/context
+
+
+## Benchmarks
+
+The benchmark suite: https://github.com/pkieltyka/go-http-routing-benchmark
+
+Results as of Nov 29, 2020 with Go 1.15.5 on Linux AMD 3950x
+
+```shell
+BenchmarkChi_Param 3075895 384 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_Param5 2116603 566 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_Param20 964117 1227 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_ParamWrite 2863413 420 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_GithubStatic 3045488 395 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_GithubParam 2204115 540 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_GithubAll 10000 113811 ns/op 81203 B/op 406 allocs/op
+BenchmarkChi_GPlusStatic 3337485 359 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_GPlusParam 2825853 423 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_GPlus2Params 2471697 483 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_GPlusAll 194220 5950 ns/op 5200 B/op 26 allocs/op
+BenchmarkChi_ParseStatic 3365324 356 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_ParseParam 2976614 404 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_Parse2Params 2638084 439 ns/op 400 B/op 2 allocs/op
+BenchmarkChi_ParseAll 109567 11295 ns/op 10400 B/op 52 allocs/op
+BenchmarkChi_StaticAll 16846 71308 ns/op 62802 B/op 314 allocs/op
+```
+
+Comparison with other routers: https://gist.github.com/pkieltyka/123032f12052520aaccab752bd3e78cc
+
+NOTE: the allocs in the benchmark above are from the calls to http.Request's
+`WithContext(context.Context)` method that clones the http.Request, sets the `Context()`
+on the duplicated (alloc'd) request and returns it the new request object. This is just
+how setting context on a request in Go works.
+
+
+## Go module support & note on chi's versioning
+
+* Go.mod support means we reset our versioning starting from v1.5 (see [CHANGELOG](https://github.com/go-chi/chi/blob/master/CHANGELOG.md#v150-2020-11-12---now-with-gomod-support))
+* All older tags are preserved, are backwards-compatible and will "just work" as they
+* Brand new systems can run `go get -u github.com/go-chi/chi` as normal, or `go get -u github.com/go-chi/chi@latest`
+to install chi, which will install v1.x+ built with go.mod support, starting from v1.5.0.
+* For existing projects who want to upgrade to the latest go.mod version, run: `go get -u github.com/go-chi/chi@v1.5.0`,
+which will get you on the go.mod version line (as Go's mod cache may still remember v4.x).
+* Any breaking changes will bump a "minor" release and backwards-compatible improvements/fixes will bump a "tiny" release.
+
+
+## Credits
+
+* Carl Jackson for https://github.com/zenazn/goji
+ * Parts of chi's thinking comes from goji, and chi's middleware package
+ sources from goji.
+* Armon Dadgar for https://github.com/armon/go-radix
+* Contributions: [@VojtechVitek](https://github.com/VojtechVitek)
+
+We'll be more than happy to see [your contributions](./CONTRIBUTING.md)!
+
+
+## Beyond REST
+
+chi is just a http router that lets you decompose request handling into many smaller layers.
+Many companies use chi to write REST services for their public APIs. But, REST is just a convention
+for managing state via HTTP, and there's a lot of other pieces required to write a complete client-server
+system or network of microservices.
+
+Looking beyond REST, I also recommend some newer works in the field:
+* [webrpc](https://github.com/webrpc/webrpc) - Web-focused RPC client+server framework with code-gen
+* [gRPC](https://github.com/grpc/grpc-go) - Google's RPC framework via protobufs
+* [graphql](https://github.com/99designs/gqlgen) - Declarative query language
+* [NATS](https://nats.io) - lightweight pub-sub
+
+
+## License
+
+Copyright (c) 2015-present [Peter Kieltyka](https://github.com/pkieltyka)
+
+Licensed under [MIT License](./LICENSE)
+
+[GoDoc]: https://pkg.go.dev/github.com/go-chi/chi?tab=versions
+[GoDoc Widget]: https://godoc.org/github.com/go-chi/chi?status.svg
+[Travis]: https://travis-ci.org/go-chi/chi
+[Travis Widget]: https://travis-ci.org/go-chi/chi.svg?branch=master
diff --git a/vendor/github.com/go-chi/chi/chain.go b/vendor/github.com/go-chi/chi/chain.go
index 88e6846138..a8e7384633 100644
--- a/vendor/github.com/go-chi/chi/chain.go
+++ b/vendor/github.com/go-chi/chi/chain.go
@@ -1,49 +1,49 @@
-package chi
-
-import "net/http"
-
-// Chain returns a Middlewares type from a slice of middleware handlers.
-func Chain(middlewares ...func(http.Handler) http.Handler) Middlewares {
- return Middlewares(middlewares)
-}
-
-// Handler builds and returns a http.Handler from the chain of middlewares,
-// with `h http.Handler` as the final handler.
-func (mws Middlewares) Handler(h http.Handler) http.Handler {
- return &ChainHandler{mws, h, chain(mws, h)}
-}
-
-// HandlerFunc builds and returns a http.Handler from the chain of middlewares,
-// with `h http.Handler` as the final handler.
-func (mws Middlewares) HandlerFunc(h http.HandlerFunc) http.Handler {
- return &ChainHandler{mws, h, chain(mws, h)}
-}
-
-// ChainHandler is a http.Handler with support for handler composition and
-// execution.
-type ChainHandler struct {
- Middlewares Middlewares
- Endpoint http.Handler
- chain http.Handler
-}
-
-func (c *ChainHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
- c.chain.ServeHTTP(w, r)
-}
-
-// chain builds a http.Handler composed of an inline middleware stack and endpoint
-// handler in the order they are passed.
-func chain(middlewares []func(http.Handler) http.Handler, endpoint http.Handler) http.Handler {
- // Return ahead of time if there aren't any middlewares for the chain
- if len(middlewares) == 0 {
- return endpoint
- }
-
- // Wrap the end handler with the middleware chain
- h := middlewares[len(middlewares)-1](endpoint)
- for i := len(middlewares) - 2; i >= 0; i-- {
- h = middlewares[i](h)
- }
-
- return h
-}
+package chi
+
+import "net/http"
+
+// Chain returns a Middlewares type from a slice of middleware handlers.
+func Chain(middlewares ...func(http.Handler) http.Handler) Middlewares {
+ return Middlewares(middlewares)
+}
+
+// Handler builds and returns a http.Handler from the chain of middlewares,
+// with `h http.Handler` as the final handler.
+func (mws Middlewares) Handler(h http.Handler) http.Handler {
+ return &ChainHandler{mws, h, chain(mws, h)}
+}
+
+// HandlerFunc builds and returns a http.Handler from the chain of middlewares,
+// with `h http.Handler` as the final handler.
+func (mws Middlewares) HandlerFunc(h http.HandlerFunc) http.Handler {
+ return &ChainHandler{mws, h, chain(mws, h)}
+}
+
+// ChainHandler is a http.Handler with support for handler composition and
+// execution.
+type ChainHandler struct {
+ Middlewares Middlewares
+ Endpoint http.Handler
+ chain http.Handler
+}
+
+func (c *ChainHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ c.chain.ServeHTTP(w, r)
+}
+
+// chain builds a http.Handler composed of an inline middleware stack and endpoint
+// handler in the order they are passed.
+func chain(middlewares []func(http.Handler) http.Handler, endpoint http.Handler) http.Handler {
+ // Return ahead of time if there aren't any middlewares for the chain
+ if len(middlewares) == 0 {
+ return endpoint
+ }
+
+ // Wrap the end handler with the middleware chain
+ h := middlewares[len(middlewares)-1](endpoint)
+ for i := len(middlewares) - 2; i >= 0; i-- {
+ h = middlewares[i](h)
+ }
+
+ return h
+}
diff --git a/vendor/github.com/go-chi/chi/chi.go b/vendor/github.com/go-chi/chi/chi.go
index b7063dc297..5872efb17f 100644
--- a/vendor/github.com/go-chi/chi/chi.go
+++ b/vendor/github.com/go-chi/chi/chi.go
@@ -1,134 +1,134 @@
-//
-// Package chi is a small, idiomatic and composable router for building HTTP services.
-//
-// chi requires Go 1.10 or newer.
-//
-// Example:
-// package main
-//
-// import (
-// "net/http"
-//
-// "github.com/go-chi/chi"
-// "github.com/go-chi/chi/middleware"
-// )
-//
-// func main() {
-// r := chi.NewRouter()
-// r.Use(middleware.Logger)
-// r.Use(middleware.Recoverer)
-//
-// r.Get("/", func(w http.ResponseWriter, r *http.Request) {
-// w.Write([]byte("root."))
-// })
-//
-// http.ListenAndServe(":3333", r)
-// }
-//
-// See github.com/go-chi/chi/_examples/ for more in-depth examples.
-//
-// URL patterns allow for easy matching of path components in HTTP
-// requests. The matching components can then be accessed using
-// chi.URLParam(). All patterns must begin with a slash.
-//
-// A simple named placeholder {name} matches any sequence of characters
-// up to the next / or the end of the URL. Trailing slashes on paths must
-// be handled explicitly.
-//
-// A placeholder with a name followed by a colon allows a regular
-// expression match, for example {number:\\d+}. The regular expression
-// syntax is Go's normal regexp RE2 syntax, except that regular expressions
-// including { or } are not supported, and / will never be
-// matched. An anonymous regexp pattern is allowed, using an empty string
-// before the colon in the placeholder, such as {:\\d+}
-//
-// The special placeholder of asterisk matches the rest of the requested
-// URL. Any trailing characters in the pattern are ignored. This is the only
-// placeholder which will match / characters.
-//
-// Examples:
-// "/user/{name}" matches "/user/jsmith" but not "/user/jsmith/info" or "/user/jsmith/"
-// "/user/{name}/info" matches "/user/jsmith/info"
-// "/page/*" matches "/page/intro/latest"
-// "/page/*/index" also matches "/page/intro/latest"
-// "/date/{yyyy:\\d\\d\\d\\d}/{mm:\\d\\d}/{dd:\\d\\d}" matches "/date/2017/04/01"
-//
-package chi
-
-import "net/http"
-
-// NewRouter returns a new Mux object that implements the Router interface.
-func NewRouter() *Mux {
- return NewMux()
-}
-
-// Router consisting of the core routing methods used by chi's Mux,
-// using only the standard net/http.
-type Router interface {
- http.Handler
- Routes
-
- // Use appends one or more middlewares onto the Router stack.
- Use(middlewares ...func(http.Handler) http.Handler)
-
- // With adds inline middlewares for an endpoint handler.
- With(middlewares ...func(http.Handler) http.Handler) Router
-
- // Group adds a new inline-Router along the current routing
- // path, with a fresh middleware stack for the inline-Router.
- Group(fn func(r Router)) Router
-
- // Route mounts a sub-Router along a `pattern`` string.
- Route(pattern string, fn func(r Router)) Router
-
- // Mount attaches another http.Handler along ./pattern/*
- Mount(pattern string, h http.Handler)
-
- // Handle and HandleFunc adds routes for `pattern` that matches
- // all HTTP methods.
- Handle(pattern string, h http.Handler)
- HandleFunc(pattern string, h http.HandlerFunc)
-
- // Method and MethodFunc adds routes for `pattern` that matches
- // the `method` HTTP method.
- Method(method, pattern string, h http.Handler)
- MethodFunc(method, pattern string, h http.HandlerFunc)
-
- // HTTP-method routing along `pattern`
- Connect(pattern string, h http.HandlerFunc)
- Delete(pattern string, h http.HandlerFunc)
- Get(pattern string, h http.HandlerFunc)
- Head(pattern string, h http.HandlerFunc)
- Options(pattern string, h http.HandlerFunc)
- Patch(pattern string, h http.HandlerFunc)
- Post(pattern string, h http.HandlerFunc)
- Put(pattern string, h http.HandlerFunc)
- Trace(pattern string, h http.HandlerFunc)
-
- // NotFound defines a handler to respond whenever a route could
- // not be found.
- NotFound(h http.HandlerFunc)
-
- // MethodNotAllowed defines a handler to respond whenever a method is
- // not allowed.
- MethodNotAllowed(h http.HandlerFunc)
-}
-
-// Routes interface adds two methods for router traversal, which is also
-// used by the `docgen` subpackage to generation documentation for Routers.
-type Routes interface {
- // Routes returns the routing tree in an easily traversable structure.
- Routes() []Route
-
- // Middlewares returns the list of middlewares in use by the router.
- Middlewares() Middlewares
-
- // Match searches the routing tree for a handler that matches
- // the method/path - similar to routing a http request, but without
- // executing the handler thereafter.
- Match(rctx *Context, method, path string) bool
-}
-
-// Middlewares type is a slice of standard middleware handlers with methods
-// to compose middleware chains and http.Handler's.
-type Middlewares []func(http.Handler) http.Handler
+//
+// Package chi is a small, idiomatic and composable router for building HTTP services.
+//
+// chi requires Go 1.10 or newer.
+//
+// Example:
+// package main
+//
+// import (
+// "net/http"
+//
+// "github.com/go-chi/chi"
+// "github.com/go-chi/chi/middleware"
+// )
+//
+// func main() {
+// r := chi.NewRouter()
+// r.Use(middleware.Logger)
+// r.Use(middleware.Recoverer)
+//
+// r.Get("/", func(w http.ResponseWriter, r *http.Request) {
+// w.Write([]byte("root."))
+// })
+//
+// http.ListenAndServe(":3333", r)
+// }
+//
+// See github.com/go-chi/chi/_examples/ for more in-depth examples.
+//
+// URL patterns allow for easy matching of path components in HTTP
+// requests. The matching components can then be accessed using
+// chi.URLParam(). All patterns must begin with a slash.
+//
+// A simple named placeholder {name} matches any sequence of characters
+// up to the next / or the end of the URL. Trailing slashes on paths must
+// be handled explicitly.
+//
+// A placeholder with a name followed by a colon allows a regular
+// expression match, for example {number:\\d+}. The regular expression
+// syntax is Go's normal regexp RE2 syntax, except that regular expressions
+// including { or } are not supported, and / will never be
+// matched. An anonymous regexp pattern is allowed, using an empty string
+// before the colon in the placeholder, such as {:\\d+}
+//
+// The special placeholder of asterisk matches the rest of the requested
+// URL. Any trailing characters in the pattern are ignored. This is the only
+// placeholder which will match / characters.
+//
+// Examples:
+// "/user/{name}" matches "/user/jsmith" but not "/user/jsmith/info" or "/user/jsmith/"
+// "/user/{name}/info" matches "/user/jsmith/info"
+// "/page/*" matches "/page/intro/latest"
+// "/page/*/index" also matches "/page/intro/latest"
+// "/date/{yyyy:\\d\\d\\d\\d}/{mm:\\d\\d}/{dd:\\d\\d}" matches "/date/2017/04/01"
+//
+package chi
+
+import "net/http"
+
+// NewRouter returns a new Mux object that implements the Router interface.
+func NewRouter() *Mux {
+ return NewMux()
+}
+
+// Router consisting of the core routing methods used by chi's Mux,
+// using only the standard net/http.
+type Router interface {
+ http.Handler
+ Routes
+
+ // Use appends one or more middlewares onto the Router stack.
+ Use(middlewares ...func(http.Handler) http.Handler)
+
+ // With adds inline middlewares for an endpoint handler.
+ With(middlewares ...func(http.Handler) http.Handler) Router
+
+ // Group adds a new inline-Router along the current routing
+ // path, with a fresh middleware stack for the inline-Router.
+ Group(fn func(r Router)) Router
+
+ // Route mounts a sub-Router along a `pattern`` string.
+ Route(pattern string, fn func(r Router)) Router
+
+ // Mount attaches another http.Handler along ./pattern/*
+ Mount(pattern string, h http.Handler)
+
+ // Handle and HandleFunc adds routes for `pattern` that matches
+ // all HTTP methods.
+ Handle(pattern string, h http.Handler)
+ HandleFunc(pattern string, h http.HandlerFunc)
+
+ // Method and MethodFunc adds routes for `pattern` that matches
+ // the `method` HTTP method.
+ Method(method, pattern string, h http.Handler)
+ MethodFunc(method, pattern string, h http.HandlerFunc)
+
+ // HTTP-method routing along `pattern`
+ Connect(pattern string, h http.HandlerFunc)
+ Delete(pattern string, h http.HandlerFunc)
+ Get(pattern string, h http.HandlerFunc)
+ Head(pattern string, h http.HandlerFunc)
+ Options(pattern string, h http.HandlerFunc)
+ Patch(pattern string, h http.HandlerFunc)
+ Post(pattern string, h http.HandlerFunc)
+ Put(pattern string, h http.HandlerFunc)
+ Trace(pattern string, h http.HandlerFunc)
+
+ // NotFound defines a handler to respond whenever a route could
+ // not be found.
+ NotFound(h http.HandlerFunc)
+
+ // MethodNotAllowed defines a handler to respond whenever a method is
+ // not allowed.
+ MethodNotAllowed(h http.HandlerFunc)
+}
+
+// Routes interface adds two methods for router traversal, which is also
+// used by the `docgen` subpackage to generation documentation for Routers.
+type Routes interface {
+ // Routes returns the routing tree in an easily traversable structure.
+ Routes() []Route
+
+ // Middlewares returns the list of middlewares in use by the router.
+ Middlewares() Middlewares
+
+ // Match searches the routing tree for a handler that matches
+ // the method/path - similar to routing a http request, but without
+ // executing the handler thereafter.
+ Match(rctx *Context, method, path string) bool
+}
+
+// Middlewares type is a slice of standard middleware handlers with methods
+// to compose middleware chains and http.Handler's.
+type Middlewares []func(http.Handler) http.Handler
diff --git a/vendor/github.com/go-chi/chi/context.go b/vendor/github.com/go-chi/chi/context.go
index 8c97f214a9..9f60d0a282 100644
--- a/vendor/github.com/go-chi/chi/context.go
+++ b/vendor/github.com/go-chi/chi/context.go
@@ -1,157 +1,157 @@
-package chi
-
-import (
- "context"
- "net/http"
- "strings"
-)
-
-// URLParam returns the url parameter from a http.Request object.
-func URLParam(r *http.Request, key string) string {
- if rctx := RouteContext(r.Context()); rctx != nil {
- return rctx.URLParam(key)
- }
- return ""
-}
-
-// URLParamFromCtx returns the url parameter from a http.Request Context.
-func URLParamFromCtx(ctx context.Context, key string) string {
- if rctx := RouteContext(ctx); rctx != nil {
- return rctx.URLParam(key)
- }
- return ""
-}
-
-// RouteContext returns chi's routing Context object from a
-// http.Request Context.
-func RouteContext(ctx context.Context) *Context {
- val, _ := ctx.Value(RouteCtxKey).(*Context)
- return val
-}
-
-// NewRouteContext returns a new routing Context object.
-func NewRouteContext() *Context {
- return &Context{}
-}
-
-var (
- // RouteCtxKey is the context.Context key to store the request context.
- RouteCtxKey = &contextKey{"RouteContext"}
-)
-
-// Context is the default routing context set on the root node of a
-// request context to track route patterns, URL parameters and
-// an optional routing path.
-type Context struct {
- Routes Routes
-
- // Routing path/method override used during the route search.
- // See Mux#routeHTTP method.
- RoutePath string
- RouteMethod string
-
- // Routing pattern stack throughout the lifecycle of the request,
- // across all connected routers. It is a record of all matching
- // patterns across a stack of sub-routers.
- RoutePatterns []string
-
- // URLParams are the stack of routeParams captured during the
- // routing lifecycle across a stack of sub-routers.
- URLParams RouteParams
-
- // The endpoint routing pattern that matched the request URI path
- // or `RoutePath` of the current sub-router. This value will update
- // during the lifecycle of a request passing through a stack of
- // sub-routers.
- routePattern string
-
- // Route parameters matched for the current sub-router. It is
- // intentionally unexported so it cant be tampered.
- routeParams RouteParams
-
- // methodNotAllowed hint
- methodNotAllowed bool
-
- // parentCtx is the parent of this one, for using Context as a
- // context.Context directly. This is an optimization that saves
- // 1 allocation.
- parentCtx context.Context
-}
-
-// Reset a routing context to its initial state.
-func (x *Context) Reset() {
- x.Routes = nil
- x.RoutePath = ""
- x.RouteMethod = ""
- x.RoutePatterns = x.RoutePatterns[:0]
- x.URLParams.Keys = x.URLParams.Keys[:0]
- x.URLParams.Values = x.URLParams.Values[:0]
-
- x.routePattern = ""
- x.routeParams.Keys = x.routeParams.Keys[:0]
- x.routeParams.Values = x.routeParams.Values[:0]
- x.methodNotAllowed = false
- x.parentCtx = nil
-}
-
-// URLParam returns the corresponding URL parameter value from the request
-// routing context.
-func (x *Context) URLParam(key string) string {
- for k := len(x.URLParams.Keys) - 1; k >= 0; k-- {
- if x.URLParams.Keys[k] == key {
- return x.URLParams.Values[k]
- }
- }
- return ""
-}
-
-// RoutePattern builds the routing pattern string for the particular
-// request, at the particular point during routing. This means, the value
-// will change throughout the execution of a request in a router. That is
-// why its advised to only use this value after calling the next handler.
-//
-// For example,
-//
-// func Instrument(next http.Handler) http.Handler {
-// return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-// next.ServeHTTP(w, r)
-// routePattern := chi.RouteContext(r.Context()).RoutePattern()
-// measure(w, r, routePattern)
-// })
-// }
-func (x *Context) RoutePattern() string {
- routePattern := strings.Join(x.RoutePatterns, "")
- return replaceWildcards(routePattern)
-}
-
-// replaceWildcards takes a route pattern and recursively replaces all
-// occurrences of "/*/" to "/".
-func replaceWildcards(p string) string {
- if strings.Contains(p, "/*/") {
- return replaceWildcards(strings.Replace(p, "/*/", "/", -1))
- }
-
- return p
-}
-
-// RouteParams is a structure to track URL routing parameters efficiently.
-type RouteParams struct {
- Keys, Values []string
-}
-
-// Add will append a URL parameter to the end of the route param
-func (s *RouteParams) Add(key, value string) {
- s.Keys = append(s.Keys, key)
- s.Values = append(s.Values, value)
-}
-
-// contextKey is a value for use with context.WithValue. It's used as
-// a pointer so it fits in an interface{} without allocation. This technique
-// for defining context keys was copied from Go 1.7's new use of context in net/http.
-type contextKey struct {
- name string
-}
-
-func (k *contextKey) String() string {
- return "chi context value " + k.name
-}
+package chi
+
+import (
+ "context"
+ "net/http"
+ "strings"
+)
+
+// URLParam returns the url parameter from a http.Request object.
+func URLParam(r *http.Request, key string) string {
+ if rctx := RouteContext(r.Context()); rctx != nil {
+ return rctx.URLParam(key)
+ }
+ return ""
+}
+
+// URLParamFromCtx returns the url parameter from a http.Request Context.
+func URLParamFromCtx(ctx context.Context, key string) string {
+ if rctx := RouteContext(ctx); rctx != nil {
+ return rctx.URLParam(key)
+ }
+ return ""
+}
+
+// RouteContext returns chi's routing Context object from a
+// http.Request Context.
+func RouteContext(ctx context.Context) *Context {
+ val, _ := ctx.Value(RouteCtxKey).(*Context)
+ return val
+}
+
+// NewRouteContext returns a new routing Context object.
+func NewRouteContext() *Context {
+ return &Context{}
+}
+
+var (
+ // RouteCtxKey is the context.Context key to store the request context.
+ RouteCtxKey = &contextKey{"RouteContext"}
+)
+
+// Context is the default routing context set on the root node of a
+// request context to track route patterns, URL parameters and
+// an optional routing path.
+type Context struct {
+ Routes Routes
+
+ // Routing path/method override used during the route search.
+ // See Mux#routeHTTP method.
+ RoutePath string
+ RouteMethod string
+
+ // Routing pattern stack throughout the lifecycle of the request,
+ // across all connected routers. It is a record of all matching
+ // patterns across a stack of sub-routers.
+ RoutePatterns []string
+
+ // URLParams are the stack of routeParams captured during the
+ // routing lifecycle across a stack of sub-routers.
+ URLParams RouteParams
+
+ // The endpoint routing pattern that matched the request URI path
+ // or `RoutePath` of the current sub-router. This value will update
+ // during the lifecycle of a request passing through a stack of
+ // sub-routers.
+ routePattern string
+
+ // Route parameters matched for the current sub-router. It is
+ // intentionally unexported so it cant be tampered.
+ routeParams RouteParams
+
+ // methodNotAllowed hint
+ methodNotAllowed bool
+
+ // parentCtx is the parent of this one, for using Context as a
+ // context.Context directly. This is an optimization that saves
+ // 1 allocation.
+ parentCtx context.Context
+}
+
+// Reset a routing context to its initial state.
+func (x *Context) Reset() {
+ x.Routes = nil
+ x.RoutePath = ""
+ x.RouteMethod = ""
+ x.RoutePatterns = x.RoutePatterns[:0]
+ x.URLParams.Keys = x.URLParams.Keys[:0]
+ x.URLParams.Values = x.URLParams.Values[:0]
+
+ x.routePattern = ""
+ x.routeParams.Keys = x.routeParams.Keys[:0]
+ x.routeParams.Values = x.routeParams.Values[:0]
+ x.methodNotAllowed = false
+ x.parentCtx = nil
+}
+
+// URLParam returns the corresponding URL parameter value from the request
+// routing context.
+func (x *Context) URLParam(key string) string {
+ for k := len(x.URLParams.Keys) - 1; k >= 0; k-- {
+ if x.URLParams.Keys[k] == key {
+ return x.URLParams.Values[k]
+ }
+ }
+ return ""
+}
+
+// RoutePattern builds the routing pattern string for the particular
+// request, at the particular point during routing. This means, the value
+// will change throughout the execution of a request in a router. That is
+// why its advised to only use this value after calling the next handler.
+//
+// For example,
+//
+// func Instrument(next http.Handler) http.Handler {
+// return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+// next.ServeHTTP(w, r)
+// routePattern := chi.RouteContext(r.Context()).RoutePattern()
+// measure(w, r, routePattern)
+// })
+// }
+func (x *Context) RoutePattern() string {
+ routePattern := strings.Join(x.RoutePatterns, "")
+ return replaceWildcards(routePattern)
+}
+
+// replaceWildcards takes a route pattern and recursively replaces all
+// occurrences of "/*/" to "/".
+func replaceWildcards(p string) string {
+ if strings.Contains(p, "/*/") {
+ return replaceWildcards(strings.Replace(p, "/*/", "/", -1))
+ }
+
+ return p
+}
+
+// RouteParams is a structure to track URL routing parameters efficiently.
+type RouteParams struct {
+ Keys, Values []string
+}
+
+// Add will append a URL parameter to the end of the route param
+func (s *RouteParams) Add(key, value string) {
+ s.Keys = append(s.Keys, key)
+ s.Values = append(s.Values, value)
+}
+
+// contextKey is a value for use with context.WithValue. It's used as
+// a pointer so it fits in an interface{} without allocation. This technique
+// for defining context keys was copied from Go 1.7's new use of context in net/http.
+type contextKey struct {
+ name string
+}
+
+func (k *contextKey) String() string {
+ return "chi context value " + k.name
+}
diff --git a/vendor/github.com/go-chi/chi/mux.go b/vendor/github.com/go-chi/chi/mux.go
index 146643b04c..793fb880fc 100644
--- a/vendor/github.com/go-chi/chi/mux.go
+++ b/vendor/github.com/go-chi/chi/mux.go
@@ -1,479 +1,479 @@
-package chi
-
-import (
- "context"
- "fmt"
- "net/http"
- "strings"
- "sync"
-)
-
-var _ Router = &Mux{}
-
-// Mux is a simple HTTP route multiplexer that parses a request path,
-// records any URL params, and executes an end handler. It implements
-// the http.Handler interface and is friendly with the standard library.
-//
-// Mux is designed to be fast, minimal and offer a powerful API for building
-// modular and composable HTTP services with a large set of handlers. It's
-// particularly useful for writing large REST API services that break a handler
-// into many smaller parts composed of middlewares and end handlers.
-type Mux struct {
- // The radix trie router
- tree *node
-
- // The middleware stack
- middlewares []func(http.Handler) http.Handler
-
- // Controls the behaviour of middleware chain generation when a mux
- // is registered as an inline group inside another mux.
- inline bool
- parent *Mux
-
- // The computed mux handler made of the chained middleware stack and
- // the tree router
- handler http.Handler
-
- // Routing context pool
- pool *sync.Pool
-
- // Custom route not found handler
- notFoundHandler http.HandlerFunc
-
- // Custom method not allowed handler
- methodNotAllowedHandler http.HandlerFunc
-}
-
-// NewMux returns a newly initialized Mux object that implements the Router
-// interface.
-func NewMux() *Mux {
- mux := &Mux{tree: &node{}, pool: &sync.Pool{}}
- mux.pool.New = func() interface{} {
- return NewRouteContext()
- }
- return mux
-}
-
-// ServeHTTP is the single method of the http.Handler interface that makes
-// Mux interoperable with the standard library. It uses a sync.Pool to get and
-// reuse routing contexts for each request.
-func (mx *Mux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
- // Ensure the mux has some routes defined on the mux
- if mx.handler == nil {
- mx.NotFoundHandler().ServeHTTP(w, r)
- return
- }
-
- // Check if a routing context already exists from a parent router.
- rctx, _ := r.Context().Value(RouteCtxKey).(*Context)
- if rctx != nil {
- mx.handler.ServeHTTP(w, r)
- return
- }
-
- // Fetch a RouteContext object from the sync pool, and call the computed
- // mx.handler that is comprised of mx.middlewares + mx.routeHTTP.
- // Once the request is finished, reset the routing context and put it back
- // into the pool for reuse from another request.
- rctx = mx.pool.Get().(*Context)
- rctx.Reset()
- rctx.Routes = mx
- rctx.parentCtx = r.Context()
-
- // NOTE: r.WithContext() causes 2 allocations and context.WithValue() causes 1 allocation
- r = r.WithContext(context.WithValue(r.Context(), RouteCtxKey, rctx))
-
- // Serve the request and once its done, put the request context back in the sync pool
- mx.handler.ServeHTTP(w, r)
- mx.pool.Put(rctx)
-}
-
-// Use appends a middleware handler to the Mux middleware stack.
-//
-// The middleware stack for any Mux will execute before searching for a matching
-// route to a specific handler, which provides opportunity to respond early,
-// change the course of the request execution, or set request-scoped values for
-// the next http.Handler.
-func (mx *Mux) Use(middlewares ...func(http.Handler) http.Handler) {
- if mx.handler != nil {
- panic("chi: all middlewares must be defined before routes on a mux")
- }
- mx.middlewares = append(mx.middlewares, middlewares...)
-}
-
-// Handle adds the route `pattern` that matches any http method to
-// execute the `handler` http.Handler.
-func (mx *Mux) Handle(pattern string, handler http.Handler) {
- mx.handle(mALL, pattern, handler)
-}
-
-// HandleFunc adds the route `pattern` that matches any http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) HandleFunc(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mALL, pattern, handlerFn)
-}
-
-// Method adds the route `pattern` that matches `method` http method to
-// execute the `handler` http.Handler.
-func (mx *Mux) Method(method, pattern string, handler http.Handler) {
- m, ok := methodMap[strings.ToUpper(method)]
- if !ok {
- panic(fmt.Sprintf("chi: '%s' http method is not supported.", method))
- }
- mx.handle(m, pattern, handler)
-}
-
-// MethodFunc adds the route `pattern` that matches `method` http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) MethodFunc(method, pattern string, handlerFn http.HandlerFunc) {
- mx.Method(method, pattern, handlerFn)
-}
-
-// Connect adds the route `pattern` that matches a CONNECT http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Connect(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mCONNECT, pattern, handlerFn)
-}
-
-// Delete adds the route `pattern` that matches a DELETE http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Delete(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mDELETE, pattern, handlerFn)
-}
-
-// Get adds the route `pattern` that matches a GET http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Get(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mGET, pattern, handlerFn)
-}
-
-// Head adds the route `pattern` that matches a HEAD http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Head(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mHEAD, pattern, handlerFn)
-}
-
-// Options adds the route `pattern` that matches a OPTIONS http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Options(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mOPTIONS, pattern, handlerFn)
-}
-
-// Patch adds the route `pattern` that matches a PATCH http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Patch(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mPATCH, pattern, handlerFn)
-}
-
-// Post adds the route `pattern` that matches a POST http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Post(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mPOST, pattern, handlerFn)
-}
-
-// Put adds the route `pattern` that matches a PUT http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Put(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mPUT, pattern, handlerFn)
-}
-
-// Trace adds the route `pattern` that matches a TRACE http method to
-// execute the `handlerFn` http.HandlerFunc.
-func (mx *Mux) Trace(pattern string, handlerFn http.HandlerFunc) {
- mx.handle(mTRACE, pattern, handlerFn)
-}
-
-// NotFound sets a custom http.HandlerFunc for routing paths that could
-// not be found. The default 404 handler is `http.NotFound`.
-func (mx *Mux) NotFound(handlerFn http.HandlerFunc) {
- // Build NotFound handler chain
- m := mx
- h := Chain(mx.middlewares...).HandlerFunc(handlerFn).ServeHTTP
- if mx.inline && mx.parent != nil {
- m = mx.parent
- }
-
- // Update the notFoundHandler from this point forward
- m.notFoundHandler = h
- m.updateSubRoutes(func(subMux *Mux) {
- if subMux.notFoundHandler == nil {
- subMux.NotFound(h)
- }
- })
-}
-
-// MethodNotAllowed sets a custom http.HandlerFunc for routing paths where the
-// method is unresolved. The default handler returns a 405 with an empty body.
-func (mx *Mux) MethodNotAllowed(handlerFn http.HandlerFunc) {
- // Build MethodNotAllowed handler chain
- m := mx
- h := Chain(mx.middlewares...).HandlerFunc(handlerFn).ServeHTTP
- if mx.inline && mx.parent != nil {
- m = mx.parent
- }
-
- // Update the methodNotAllowedHandler from this point forward
- m.methodNotAllowedHandler = h
- m.updateSubRoutes(func(subMux *Mux) {
- if subMux.methodNotAllowedHandler == nil {
- subMux.MethodNotAllowed(h)
- }
- })
-}
-
-// With adds inline middlewares for an endpoint handler.
-func (mx *Mux) With(middlewares ...func(http.Handler) http.Handler) Router {
- // Similarly as in handle(), we must build the mux handler once additional
- // middleware registration isn't allowed for this stack, like now.
- if !mx.inline && mx.handler == nil {
- mx.updateRouteHandler()
- }
-
- // Copy middlewares from parent inline muxs
- var mws Middlewares
- if mx.inline {
- mws = make(Middlewares, len(mx.middlewares))
- copy(mws, mx.middlewares)
- }
- mws = append(mws, middlewares...)
-
- im := &Mux{
- pool: mx.pool, inline: true, parent: mx, tree: mx.tree, middlewares: mws,
- notFoundHandler: mx.notFoundHandler, methodNotAllowedHandler: mx.methodNotAllowedHandler,
- }
-
- return im
-}
-
-// Group creates a new inline-Mux with a fresh middleware stack. It's useful
-// for a group of handlers along the same routing path that use an additional
-// set of middlewares. See _examples/.
-func (mx *Mux) Group(fn func(r Router)) Router {
- im := mx.With().(*Mux)
- if fn != nil {
- fn(im)
- }
- return im
-}
-
-// Route creates a new Mux with a fresh middleware stack and mounts it
-// along the `pattern` as a subrouter. Effectively, this is a short-hand
-// call to Mount. See _examples/.
-func (mx *Mux) Route(pattern string, fn func(r Router)) Router {
- if fn == nil {
- panic(fmt.Sprintf("chi: attempting to Route() a nil subrouter on '%s'", pattern))
- }
- subRouter := NewRouter()
- fn(subRouter)
- mx.Mount(pattern, subRouter)
- return subRouter
-}
-
-// Mount attaches another http.Handler or chi Router as a subrouter along a routing
-// path. It's very useful to split up a large API as many independent routers and
-// compose them as a single service using Mount. See _examples/.
-//
-// Note that Mount() simply sets a wildcard along the `pattern` that will continue
-// routing at the `handler`, which in most cases is another chi.Router. As a result,
-// if you define two Mount() routes on the exact same pattern the mount will panic.
-func (mx *Mux) Mount(pattern string, handler http.Handler) {
- if handler == nil {
- panic(fmt.Sprintf("chi: attempting to Mount() a nil handler on '%s'", pattern))
- }
-
- // Provide runtime safety for ensuring a pattern isn't mounted on an existing
- // routing pattern.
- if mx.tree.findPattern(pattern+"*") || mx.tree.findPattern(pattern+"/*") {
- panic(fmt.Sprintf("chi: attempting to Mount() a handler on an existing path, '%s'", pattern))
- }
-
- // Assign sub-Router's with the parent not found & method not allowed handler if not specified.
- subr, ok := handler.(*Mux)
- if ok && subr.notFoundHandler == nil && mx.notFoundHandler != nil {
- subr.NotFound(mx.notFoundHandler)
- }
- if ok && subr.methodNotAllowedHandler == nil && mx.methodNotAllowedHandler != nil {
- subr.MethodNotAllowed(mx.methodNotAllowedHandler)
- }
-
- mountHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
- rctx := RouteContext(r.Context())
-
- // shift the url path past the previous subrouter
- rctx.RoutePath = mx.nextRoutePath(rctx)
-
- // reset the wildcard URLParam which connects the subrouter
- n := len(rctx.URLParams.Keys) - 1
- if n >= 0 && rctx.URLParams.Keys[n] == "*" && len(rctx.URLParams.Values) > n {
- rctx.URLParams.Values[n] = ""
- }
-
- handler.ServeHTTP(w, r)
- })
-
- if pattern == "" || pattern[len(pattern)-1] != '/' {
- mx.handle(mALL|mSTUB, pattern, mountHandler)
- mx.handle(mALL|mSTUB, pattern+"/", mountHandler)
- pattern += "/"
- }
-
- method := mALL
- subroutes, _ := handler.(Routes)
- if subroutes != nil {
- method |= mSTUB
- }
- n := mx.handle(method, pattern+"*", mountHandler)
-
- if subroutes != nil {
- n.subroutes = subroutes
- }
-}
-
-// Routes returns a slice of routing information from the tree,
-// useful for traversing available routes of a router.
-func (mx *Mux) Routes() []Route {
- return mx.tree.routes()
-}
-
-// Middlewares returns a slice of middleware handler functions.
-func (mx *Mux) Middlewares() Middlewares {
- return mx.middlewares
-}
-
-// Match searches the routing tree for a handler that matches the method/path.
-// It's similar to routing a http request, but without executing the handler
-// thereafter.
-//
-// Note: the *Context state is updated during execution, so manage
-// the state carefully or make a NewRouteContext().
-func (mx *Mux) Match(rctx *Context, method, path string) bool {
- m, ok := methodMap[method]
- if !ok {
- return false
- }
-
- node, _, h := mx.tree.FindRoute(rctx, m, path)
-
- if node != nil && node.subroutes != nil {
- rctx.RoutePath = mx.nextRoutePath(rctx)
- return node.subroutes.Match(rctx, method, rctx.RoutePath)
- }
-
- return h != nil
-}
-
-// NotFoundHandler returns the default Mux 404 responder whenever a route
-// cannot be found.
-func (mx *Mux) NotFoundHandler() http.HandlerFunc {
- if mx.notFoundHandler != nil {
- return mx.notFoundHandler
- }
- return http.NotFound
-}
-
-// MethodNotAllowedHandler returns the default Mux 405 responder whenever
-// a method cannot be resolved for a route.
-func (mx *Mux) MethodNotAllowedHandler() http.HandlerFunc {
- if mx.methodNotAllowedHandler != nil {
- return mx.methodNotAllowedHandler
- }
- return methodNotAllowedHandler
-}
-
-// handle registers a http.Handler in the routing tree for a particular http method
-// and routing pattern.
-func (mx *Mux) handle(method methodTyp, pattern string, handler http.Handler) *node {
- if len(pattern) == 0 || pattern[0] != '/' {
- panic(fmt.Sprintf("chi: routing pattern must begin with '/' in '%s'", pattern))
- }
-
- // Build the computed routing handler for this routing pattern.
- if !mx.inline && mx.handler == nil {
- mx.updateRouteHandler()
- }
-
- // Build endpoint handler with inline middlewares for the route
- var h http.Handler
- if mx.inline {
- mx.handler = http.HandlerFunc(mx.routeHTTP)
- h = Chain(mx.middlewares...).Handler(handler)
- } else {
- h = handler
- }
-
- // Add the endpoint to the tree and return the node
- return mx.tree.InsertRoute(method, pattern, h)
-}
-
-// routeHTTP routes a http.Request through the Mux routing tree to serve
-// the matching handler for a particular http method.
-func (mx *Mux) routeHTTP(w http.ResponseWriter, r *http.Request) {
- // Grab the route context object
- rctx := r.Context().Value(RouteCtxKey).(*Context)
-
- // The request routing path
- routePath := rctx.RoutePath
- if routePath == "" {
- if r.URL.RawPath != "" {
- routePath = r.URL.RawPath
- } else {
- routePath = r.URL.Path
- }
- }
-
- // Check if method is supported by chi
- if rctx.RouteMethod == "" {
- rctx.RouteMethod = r.Method
- }
- method, ok := methodMap[rctx.RouteMethod]
- if !ok {
- mx.MethodNotAllowedHandler().ServeHTTP(w, r)
- return
- }
-
- // Find the route
- if _, _, h := mx.tree.FindRoute(rctx, method, routePath); h != nil {
- h.ServeHTTP(w, r)
- return
- }
- if rctx.methodNotAllowed {
- mx.MethodNotAllowedHandler().ServeHTTP(w, r)
- } else {
- mx.NotFoundHandler().ServeHTTP(w, r)
- }
-}
-
-func (mx *Mux) nextRoutePath(rctx *Context) string {
- routePath := "/"
- nx := len(rctx.routeParams.Keys) - 1 // index of last param in list
- if nx >= 0 && rctx.routeParams.Keys[nx] == "*" && len(rctx.routeParams.Values) > nx {
- routePath = "/" + rctx.routeParams.Values[nx]
- }
- return routePath
-}
-
-// Recursively update data on child routers.
-func (mx *Mux) updateSubRoutes(fn func(subMux *Mux)) {
- for _, r := range mx.tree.routes() {
- subMux, ok := r.SubRoutes.(*Mux)
- if !ok {
- continue
- }
- fn(subMux)
- }
-}
-
-// updateRouteHandler builds the single mux handler that is a chain of the middleware
-// stack, as defined by calls to Use(), and the tree router (Mux) itself. After this
-// point, no other middlewares can be registered on this Mux's stack. But you can still
-// compose additional middlewares via Group()'s or using a chained middleware handler.
-func (mx *Mux) updateRouteHandler() {
- mx.handler = chain(mx.middlewares, http.HandlerFunc(mx.routeHTTP))
-}
-
-// methodNotAllowedHandler is a helper function to respond with a 405,
-// method not allowed.
-func methodNotAllowedHandler(w http.ResponseWriter, r *http.Request) {
- w.WriteHeader(405)
- w.Write(nil)
-}
+package chi
+
+import (
+ "context"
+ "fmt"
+ "net/http"
+ "strings"
+ "sync"
+)
+
+var _ Router = &Mux{}
+
+// Mux is a simple HTTP route multiplexer that parses a request path,
+// records any URL params, and executes an end handler. It implements
+// the http.Handler interface and is friendly with the standard library.
+//
+// Mux is designed to be fast, minimal and offer a powerful API for building
+// modular and composable HTTP services with a large set of handlers. It's
+// particularly useful for writing large REST API services that break a handler
+// into many smaller parts composed of middlewares and end handlers.
+type Mux struct {
+ // The radix trie router
+ tree *node
+
+ // The middleware stack
+ middlewares []func(http.Handler) http.Handler
+
+ // Controls the behaviour of middleware chain generation when a mux
+ // is registered as an inline group inside another mux.
+ inline bool
+ parent *Mux
+
+ // The computed mux handler made of the chained middleware stack and
+ // the tree router
+ handler http.Handler
+
+ // Routing context pool
+ pool *sync.Pool
+
+ // Custom route not found handler
+ notFoundHandler http.HandlerFunc
+
+ // Custom method not allowed handler
+ methodNotAllowedHandler http.HandlerFunc
+}
+
+// NewMux returns a newly initialized Mux object that implements the Router
+// interface.
+func NewMux() *Mux {
+ mux := &Mux{tree: &node{}, pool: &sync.Pool{}}
+ mux.pool.New = func() interface{} {
+ return NewRouteContext()
+ }
+ return mux
+}
+
+// ServeHTTP is the single method of the http.Handler interface that makes
+// Mux interoperable with the standard library. It uses a sync.Pool to get and
+// reuse routing contexts for each request.
+func (mx *Mux) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ // Ensure the mux has some routes defined on the mux
+ if mx.handler == nil {
+ mx.NotFoundHandler().ServeHTTP(w, r)
+ return
+ }
+
+ // Check if a routing context already exists from a parent router.
+ rctx, _ := r.Context().Value(RouteCtxKey).(*Context)
+ if rctx != nil {
+ mx.handler.ServeHTTP(w, r)
+ return
+ }
+
+ // Fetch a RouteContext object from the sync pool, and call the computed
+ // mx.handler that is comprised of mx.middlewares + mx.routeHTTP.
+ // Once the request is finished, reset the routing context and put it back
+ // into the pool for reuse from another request.
+ rctx = mx.pool.Get().(*Context)
+ rctx.Reset()
+ rctx.Routes = mx
+ rctx.parentCtx = r.Context()
+
+ // NOTE: r.WithContext() causes 2 allocations and context.WithValue() causes 1 allocation
+ r = r.WithContext(context.WithValue(r.Context(), RouteCtxKey, rctx))
+
+ // Serve the request and once its done, put the request context back in the sync pool
+ mx.handler.ServeHTTP(w, r)
+ mx.pool.Put(rctx)
+}
+
+// Use appends a middleware handler to the Mux middleware stack.
+//
+// The middleware stack for any Mux will execute before searching for a matching
+// route to a specific handler, which provides opportunity to respond early,
+// change the course of the request execution, or set request-scoped values for
+// the next http.Handler.
+func (mx *Mux) Use(middlewares ...func(http.Handler) http.Handler) {
+ if mx.handler != nil {
+ panic("chi: all middlewares must be defined before routes on a mux")
+ }
+ mx.middlewares = append(mx.middlewares, middlewares...)
+}
+
+// Handle adds the route `pattern` that matches any http method to
+// execute the `handler` http.Handler.
+func (mx *Mux) Handle(pattern string, handler http.Handler) {
+ mx.handle(mALL, pattern, handler)
+}
+
+// HandleFunc adds the route `pattern` that matches any http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) HandleFunc(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mALL, pattern, handlerFn)
+}
+
+// Method adds the route `pattern` that matches `method` http method to
+// execute the `handler` http.Handler.
+func (mx *Mux) Method(method, pattern string, handler http.Handler) {
+ m, ok := methodMap[strings.ToUpper(method)]
+ if !ok {
+ panic(fmt.Sprintf("chi: '%s' http method is not supported.", method))
+ }
+ mx.handle(m, pattern, handler)
+}
+
+// MethodFunc adds the route `pattern` that matches `method` http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) MethodFunc(method, pattern string, handlerFn http.HandlerFunc) {
+ mx.Method(method, pattern, handlerFn)
+}
+
+// Connect adds the route `pattern` that matches a CONNECT http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Connect(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mCONNECT, pattern, handlerFn)
+}
+
+// Delete adds the route `pattern` that matches a DELETE http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Delete(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mDELETE, pattern, handlerFn)
+}
+
+// Get adds the route `pattern` that matches a GET http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Get(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mGET, pattern, handlerFn)
+}
+
+// Head adds the route `pattern` that matches a HEAD http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Head(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mHEAD, pattern, handlerFn)
+}
+
+// Options adds the route `pattern` that matches a OPTIONS http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Options(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mOPTIONS, pattern, handlerFn)
+}
+
+// Patch adds the route `pattern` that matches a PATCH http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Patch(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mPATCH, pattern, handlerFn)
+}
+
+// Post adds the route `pattern` that matches a POST http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Post(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mPOST, pattern, handlerFn)
+}
+
+// Put adds the route `pattern` that matches a PUT http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Put(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mPUT, pattern, handlerFn)
+}
+
+// Trace adds the route `pattern` that matches a TRACE http method to
+// execute the `handlerFn` http.HandlerFunc.
+func (mx *Mux) Trace(pattern string, handlerFn http.HandlerFunc) {
+ mx.handle(mTRACE, pattern, handlerFn)
+}
+
+// NotFound sets a custom http.HandlerFunc for routing paths that could
+// not be found. The default 404 handler is `http.NotFound`.
+func (mx *Mux) NotFound(handlerFn http.HandlerFunc) {
+ // Build NotFound handler chain
+ m := mx
+ h := Chain(mx.middlewares...).HandlerFunc(handlerFn).ServeHTTP
+ if mx.inline && mx.parent != nil {
+ m = mx.parent
+ }
+
+ // Update the notFoundHandler from this point forward
+ m.notFoundHandler = h
+ m.updateSubRoutes(func(subMux *Mux) {
+ if subMux.notFoundHandler == nil {
+ subMux.NotFound(h)
+ }
+ })
+}
+
+// MethodNotAllowed sets a custom http.HandlerFunc for routing paths where the
+// method is unresolved. The default handler returns a 405 with an empty body.
+func (mx *Mux) MethodNotAllowed(handlerFn http.HandlerFunc) {
+ // Build MethodNotAllowed handler chain
+ m := mx
+ h := Chain(mx.middlewares...).HandlerFunc(handlerFn).ServeHTTP
+ if mx.inline && mx.parent != nil {
+ m = mx.parent
+ }
+
+ // Update the methodNotAllowedHandler from this point forward
+ m.methodNotAllowedHandler = h
+ m.updateSubRoutes(func(subMux *Mux) {
+ if subMux.methodNotAllowedHandler == nil {
+ subMux.MethodNotAllowed(h)
+ }
+ })
+}
+
+// With adds inline middlewares for an endpoint handler.
+func (mx *Mux) With(middlewares ...func(http.Handler) http.Handler) Router {
+ // Similarly as in handle(), we must build the mux handler once additional
+ // middleware registration isn't allowed for this stack, like now.
+ if !mx.inline && mx.handler == nil {
+ mx.updateRouteHandler()
+ }
+
+ // Copy middlewares from parent inline muxs
+ var mws Middlewares
+ if mx.inline {
+ mws = make(Middlewares, len(mx.middlewares))
+ copy(mws, mx.middlewares)
+ }
+ mws = append(mws, middlewares...)
+
+ im := &Mux{
+ pool: mx.pool, inline: true, parent: mx, tree: mx.tree, middlewares: mws,
+ notFoundHandler: mx.notFoundHandler, methodNotAllowedHandler: mx.methodNotAllowedHandler,
+ }
+
+ return im
+}
+
+// Group creates a new inline-Mux with a fresh middleware stack. It's useful
+// for a group of handlers along the same routing path that use an additional
+// set of middlewares. See _examples/.
+func (mx *Mux) Group(fn func(r Router)) Router {
+ im := mx.With().(*Mux)
+ if fn != nil {
+ fn(im)
+ }
+ return im
+}
+
+// Route creates a new Mux with a fresh middleware stack and mounts it
+// along the `pattern` as a subrouter. Effectively, this is a short-hand
+// call to Mount. See _examples/.
+func (mx *Mux) Route(pattern string, fn func(r Router)) Router {
+ if fn == nil {
+ panic(fmt.Sprintf("chi: attempting to Route() a nil subrouter on '%s'", pattern))
+ }
+ subRouter := NewRouter()
+ fn(subRouter)
+ mx.Mount(pattern, subRouter)
+ return subRouter
+}
+
+// Mount attaches another http.Handler or chi Router as a subrouter along a routing
+// path. It's very useful to split up a large API as many independent routers and
+// compose them as a single service using Mount. See _examples/.
+//
+// Note that Mount() simply sets a wildcard along the `pattern` that will continue
+// routing at the `handler`, which in most cases is another chi.Router. As a result,
+// if you define two Mount() routes on the exact same pattern the mount will panic.
+func (mx *Mux) Mount(pattern string, handler http.Handler) {
+ if handler == nil {
+ panic(fmt.Sprintf("chi: attempting to Mount() a nil handler on '%s'", pattern))
+ }
+
+ // Provide runtime safety for ensuring a pattern isn't mounted on an existing
+ // routing pattern.
+ if mx.tree.findPattern(pattern+"*") || mx.tree.findPattern(pattern+"/*") {
+ panic(fmt.Sprintf("chi: attempting to Mount() a handler on an existing path, '%s'", pattern))
+ }
+
+ // Assign sub-Router's with the parent not found & method not allowed handler if not specified.
+ subr, ok := handler.(*Mux)
+ if ok && subr.notFoundHandler == nil && mx.notFoundHandler != nil {
+ subr.NotFound(mx.notFoundHandler)
+ }
+ if ok && subr.methodNotAllowedHandler == nil && mx.methodNotAllowedHandler != nil {
+ subr.MethodNotAllowed(mx.methodNotAllowedHandler)
+ }
+
+ mountHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+ rctx := RouteContext(r.Context())
+
+ // shift the url path past the previous subrouter
+ rctx.RoutePath = mx.nextRoutePath(rctx)
+
+ // reset the wildcard URLParam which connects the subrouter
+ n := len(rctx.URLParams.Keys) - 1
+ if n >= 0 && rctx.URLParams.Keys[n] == "*" && len(rctx.URLParams.Values) > n {
+ rctx.URLParams.Values[n] = ""
+ }
+
+ handler.ServeHTTP(w, r)
+ })
+
+ if pattern == "" || pattern[len(pattern)-1] != '/' {
+ mx.handle(mALL|mSTUB, pattern, mountHandler)
+ mx.handle(mALL|mSTUB, pattern+"/", mountHandler)
+ pattern += "/"
+ }
+
+ method := mALL
+ subroutes, _ := handler.(Routes)
+ if subroutes != nil {
+ method |= mSTUB
+ }
+ n := mx.handle(method, pattern+"*", mountHandler)
+
+ if subroutes != nil {
+ n.subroutes = subroutes
+ }
+}
+
+// Routes returns a slice of routing information from the tree,
+// useful for traversing available routes of a router.
+func (mx *Mux) Routes() []Route {
+ return mx.tree.routes()
+}
+
+// Middlewares returns a slice of middleware handler functions.
+func (mx *Mux) Middlewares() Middlewares {
+ return mx.middlewares
+}
+
+// Match searches the routing tree for a handler that matches the method/path.
+// It's similar to routing a http request, but without executing the handler
+// thereafter.
+//
+// Note: the *Context state is updated during execution, so manage
+// the state carefully or make a NewRouteContext().
+func (mx *Mux) Match(rctx *Context, method, path string) bool {
+ m, ok := methodMap[method]
+ if !ok {
+ return false
+ }
+
+ node, _, h := mx.tree.FindRoute(rctx, m, path)
+
+ if node != nil && node.subroutes != nil {
+ rctx.RoutePath = mx.nextRoutePath(rctx)
+ return node.subroutes.Match(rctx, method, rctx.RoutePath)
+ }
+
+ return h != nil
+}
+
+// NotFoundHandler returns the default Mux 404 responder whenever a route
+// cannot be found.
+func (mx *Mux) NotFoundHandler() http.HandlerFunc {
+ if mx.notFoundHandler != nil {
+ return mx.notFoundHandler
+ }
+ return http.NotFound
+}
+
+// MethodNotAllowedHandler returns the default Mux 405 responder whenever
+// a method cannot be resolved for a route.
+func (mx *Mux) MethodNotAllowedHandler() http.HandlerFunc {
+ if mx.methodNotAllowedHandler != nil {
+ return mx.methodNotAllowedHandler
+ }
+ return methodNotAllowedHandler
+}
+
+// handle registers a http.Handler in the routing tree for a particular http method
+// and routing pattern.
+func (mx *Mux) handle(method methodTyp, pattern string, handler http.Handler) *node {
+ if len(pattern) == 0 || pattern[0] != '/' {
+ panic(fmt.Sprintf("chi: routing pattern must begin with '/' in '%s'", pattern))
+ }
+
+ // Build the computed routing handler for this routing pattern.
+ if !mx.inline && mx.handler == nil {
+ mx.updateRouteHandler()
+ }
+
+ // Build endpoint handler with inline middlewares for the route
+ var h http.Handler
+ if mx.inline {
+ mx.handler = http.HandlerFunc(mx.routeHTTP)
+ h = Chain(mx.middlewares...).Handler(handler)
+ } else {
+ h = handler
+ }
+
+ // Add the endpoint to the tree and return the node
+ return mx.tree.InsertRoute(method, pattern, h)
+}
+
+// routeHTTP routes a http.Request through the Mux routing tree to serve
+// the matching handler for a particular http method.
+func (mx *Mux) routeHTTP(w http.ResponseWriter, r *http.Request) {
+ // Grab the route context object
+ rctx := r.Context().Value(RouteCtxKey).(*Context)
+
+ // The request routing path
+ routePath := rctx.RoutePath
+ if routePath == "" {
+ if r.URL.RawPath != "" {
+ routePath = r.URL.RawPath
+ } else {
+ routePath = r.URL.Path
+ }
+ }
+
+ // Check if method is supported by chi
+ if rctx.RouteMethod == "" {
+ rctx.RouteMethod = r.Method
+ }
+ method, ok := methodMap[rctx.RouteMethod]
+ if !ok {
+ mx.MethodNotAllowedHandler().ServeHTTP(w, r)
+ return
+ }
+
+ // Find the route
+ if _, _, h := mx.tree.FindRoute(rctx, method, routePath); h != nil {
+ h.ServeHTTP(w, r)
+ return
+ }
+ if rctx.methodNotAllowed {
+ mx.MethodNotAllowedHandler().ServeHTTP(w, r)
+ } else {
+ mx.NotFoundHandler().ServeHTTP(w, r)
+ }
+}
+
+func (mx *Mux) nextRoutePath(rctx *Context) string {
+ routePath := "/"
+ nx := len(rctx.routeParams.Keys) - 1 // index of last param in list
+ if nx >= 0 && rctx.routeParams.Keys[nx] == "*" && len(rctx.routeParams.Values) > nx {
+ routePath = "/" + rctx.routeParams.Values[nx]
+ }
+ return routePath
+}
+
+// Recursively update data on child routers.
+func (mx *Mux) updateSubRoutes(fn func(subMux *Mux)) {
+ for _, r := range mx.tree.routes() {
+ subMux, ok := r.SubRoutes.(*Mux)
+ if !ok {
+ continue
+ }
+ fn(subMux)
+ }
+}
+
+// updateRouteHandler builds the single mux handler that is a chain of the middleware
+// stack, as defined by calls to Use(), and the tree router (Mux) itself. After this
+// point, no other middlewares can be registered on this Mux's stack. But you can still
+// compose additional middlewares via Group()'s or using a chained middleware handler.
+func (mx *Mux) updateRouteHandler() {
+ mx.handler = chain(mx.middlewares, http.HandlerFunc(mx.routeHTTP))
+}
+
+// methodNotAllowedHandler is a helper function to respond with a 405,
+// method not allowed.
+func methodNotAllowedHandler(w http.ResponseWriter, r *http.Request) {
+ w.WriteHeader(405)
+ w.Write(nil)
+}
diff --git a/vendor/github.com/go-chi/chi/tree.go b/vendor/github.com/go-chi/chi/tree.go
index 8057c52813..41954970a0 100644
--- a/vendor/github.com/go-chi/chi/tree.go
+++ b/vendor/github.com/go-chi/chi/tree.go
@@ -1,866 +1,866 @@
-package chi
-
-// Radix tree implementation below is a based on the original work by
-// Armon Dadgar in https://github.com/armon/go-radix/blob/master/radix.go
-// (MIT licensed). It's been heavily modified for use as a HTTP routing tree.
-
-import (
- "fmt"
- "net/http"
- "regexp"
- "sort"
- "strconv"
- "strings"
-)
-
-type methodTyp int
-
-const (
- mSTUB methodTyp = 1 << iota
- mCONNECT
- mDELETE
- mGET
- mHEAD
- mOPTIONS
- mPATCH
- mPOST
- mPUT
- mTRACE
-)
-
-var mALL = mCONNECT | mDELETE | mGET | mHEAD |
- mOPTIONS | mPATCH | mPOST | mPUT | mTRACE
-
-var methodMap = map[string]methodTyp{
- http.MethodConnect: mCONNECT,
- http.MethodDelete: mDELETE,
- http.MethodGet: mGET,
- http.MethodHead: mHEAD,
- http.MethodOptions: mOPTIONS,
- http.MethodPatch: mPATCH,
- http.MethodPost: mPOST,
- http.MethodPut: mPUT,
- http.MethodTrace: mTRACE,
-}
-
-// RegisterMethod adds support for custom HTTP method handlers, available
-// via Router#Method and Router#MethodFunc
-func RegisterMethod(method string) {
- if method == "" {
- return
- }
- method = strings.ToUpper(method)
- if _, ok := methodMap[method]; ok {
- return
- }
- n := len(methodMap)
- if n > strconv.IntSize-2 {
- panic(fmt.Sprintf("chi: max number of methods reached (%d)", strconv.IntSize))
- }
- mt := methodTyp(2 << n)
- methodMap[method] = mt
- mALL |= mt
-}
-
-type nodeTyp uint8
-
-const (
- ntStatic nodeTyp = iota // /home
- ntRegexp // /{id:[0-9]+}
- ntParam // /{user}
- ntCatchAll // /api/v1/*
-)
-
-type node struct {
- // node type: static, regexp, param, catchAll
- typ nodeTyp
-
- // first byte of the prefix
- label byte
-
- // first byte of the child prefix
- tail byte
-
- // prefix is the common prefix we ignore
- prefix string
-
- // regexp matcher for regexp nodes
- rex *regexp.Regexp
-
- // HTTP handler endpoints on the leaf node
- endpoints endpoints
-
- // subroutes on the leaf node
- subroutes Routes
-
- // child nodes should be stored in-order for iteration,
- // in groups of the node type.
- children [ntCatchAll + 1]nodes
-}
-
-// endpoints is a mapping of http method constants to handlers
-// for a given route.
-type endpoints map[methodTyp]*endpoint
-
-type endpoint struct {
- // endpoint handler
- handler http.Handler
-
- // pattern is the routing pattern for handler nodes
- pattern string
-
- // parameter keys recorded on handler nodes
- paramKeys []string
-}
-
-func (s endpoints) Value(method methodTyp) *endpoint {
- mh, ok := s[method]
- if !ok {
- mh = &endpoint{}
- s[method] = mh
- }
- return mh
-}
-
-func (n *node) InsertRoute(method methodTyp, pattern string, handler http.Handler) *node {
- var parent *node
- search := pattern
-
- for {
- // Handle key exhaustion
- if len(search) == 0 {
- // Insert or update the node's leaf handler
- n.setEndpoint(method, handler, pattern)
- return n
- }
-
- // We're going to be searching for a wild node next,
- // in this case, we need to get the tail
- var label = search[0]
- var segTail byte
- var segEndIdx int
- var segTyp nodeTyp
- var segRexpat string
- if label == '{' || label == '*' {
- segTyp, _, segRexpat, segTail, _, segEndIdx = patNextSegment(search)
- }
-
- var prefix string
- if segTyp == ntRegexp {
- prefix = segRexpat
- }
-
- // Look for the edge to attach to
- parent = n
- n = n.getEdge(segTyp, label, segTail, prefix)
-
- // No edge, create one
- if n == nil {
- child := &node{label: label, tail: segTail, prefix: search}
- hn := parent.addChild(child, search)
- hn.setEndpoint(method, handler, pattern)
-
- return hn
- }
-
- // Found an edge to match the pattern
-
- if n.typ > ntStatic {
- // We found a param node, trim the param from the search path and continue.
- // This param/wild pattern segment would already be on the tree from a previous
- // call to addChild when creating a new node.
- search = search[segEndIdx:]
- continue
- }
-
- // Static nodes fall below here.
- // Determine longest prefix of the search key on match.
- commonPrefix := longestPrefix(search, n.prefix)
- if commonPrefix == len(n.prefix) {
- // the common prefix is as long as the current node's prefix we're attempting to insert.
- // keep the search going.
- search = search[commonPrefix:]
- continue
- }
-
- // Split the node
- child := &node{
- typ: ntStatic,
- prefix: search[:commonPrefix],
- }
- parent.replaceChild(search[0], segTail, child)
-
- // Restore the existing node
- n.label = n.prefix[commonPrefix]
- n.prefix = n.prefix[commonPrefix:]
- child.addChild(n, n.prefix)
-
- // If the new key is a subset, set the method/handler on this node and finish.
- search = search[commonPrefix:]
- if len(search) == 0 {
- child.setEndpoint(method, handler, pattern)
- return child
- }
-
- // Create a new edge for the node
- subchild := &node{
- typ: ntStatic,
- label: search[0],
- prefix: search,
- }
- hn := child.addChild(subchild, search)
- hn.setEndpoint(method, handler, pattern)
- return hn
- }
-}
-
-// addChild appends the new `child` node to the tree using the `pattern` as the trie key.
-// For a URL router like chi's, we split the static, param, regexp and wildcard segments
-// into different nodes. In addition, addChild will recursively call itself until every
-// pattern segment is added to the url pattern tree as individual nodes, depending on type.
-func (n *node) addChild(child *node, prefix string) *node {
- search := prefix
-
- // handler leaf node added to the tree is the child.
- // this may be overridden later down the flow
- hn := child
-
- // Parse next segment
- segTyp, _, segRexpat, segTail, segStartIdx, segEndIdx := patNextSegment(search)
-
- // Add child depending on next up segment
- switch segTyp {
-
- case ntStatic:
- // Search prefix is all static (that is, has no params in path)
- // noop
-
- default:
- // Search prefix contains a param, regexp or wildcard
-
- if segTyp == ntRegexp {
- rex, err := regexp.Compile(segRexpat)
- if err != nil {
- panic(fmt.Sprintf("chi: invalid regexp pattern '%s' in route param", segRexpat))
- }
- child.prefix = segRexpat
- child.rex = rex
- }
-
- if segStartIdx == 0 {
- // Route starts with a param
- child.typ = segTyp
-
- if segTyp == ntCatchAll {
- segStartIdx = -1
- } else {
- segStartIdx = segEndIdx
- }
- if segStartIdx < 0 {
- segStartIdx = len(search)
- }
- child.tail = segTail // for params, we set the tail
-
- if segStartIdx != len(search) {
- // add static edge for the remaining part, split the end.
- // its not possible to have adjacent param nodes, so its certainly
- // going to be a static node next.
-
- search = search[segStartIdx:] // advance search position
-
- nn := &node{
- typ: ntStatic,
- label: search[0],
- prefix: search,
- }
- hn = child.addChild(nn, search)
- }
-
- } else if segStartIdx > 0 {
- // Route has some param
-
- // starts with a static segment
- child.typ = ntStatic
- child.prefix = search[:segStartIdx]
- child.rex = nil
-
- // add the param edge node
- search = search[segStartIdx:]
-
- nn := &node{
- typ: segTyp,
- label: search[0],
- tail: segTail,
- }
- hn = child.addChild(nn, search)
-
- }
- }
-
- n.children[child.typ] = append(n.children[child.typ], child)
- n.children[child.typ].Sort()
- return hn
-}
-
-func (n *node) replaceChild(label, tail byte, child *node) {
- for i := 0; i < len(n.children[child.typ]); i++ {
- if n.children[child.typ][i].label == label && n.children[child.typ][i].tail == tail {
- n.children[child.typ][i] = child
- n.children[child.typ][i].label = label
- n.children[child.typ][i].tail = tail
- return
- }
- }
- panic("chi: replacing missing child")
-}
-
-func (n *node) getEdge(ntyp nodeTyp, label, tail byte, prefix string) *node {
- nds := n.children[ntyp]
- for i := 0; i < len(nds); i++ {
- if nds[i].label == label && nds[i].tail == tail {
- if ntyp == ntRegexp && nds[i].prefix != prefix {
- continue
- }
- return nds[i]
- }
- }
- return nil
-}
-
-func (n *node) setEndpoint(method methodTyp, handler http.Handler, pattern string) {
- // Set the handler for the method type on the node
- if n.endpoints == nil {
- n.endpoints = make(endpoints)
- }
-
- paramKeys := patParamKeys(pattern)
-
- if method&mSTUB == mSTUB {
- n.endpoints.Value(mSTUB).handler = handler
- }
- if method&mALL == mALL {
- h := n.endpoints.Value(mALL)
- h.handler = handler
- h.pattern = pattern
- h.paramKeys = paramKeys
- for _, m := range methodMap {
- h := n.endpoints.Value(m)
- h.handler = handler
- h.pattern = pattern
- h.paramKeys = paramKeys
- }
- } else {
- h := n.endpoints.Value(method)
- h.handler = handler
- h.pattern = pattern
- h.paramKeys = paramKeys
- }
-}
-
-func (n *node) FindRoute(rctx *Context, method methodTyp, path string) (*node, endpoints, http.Handler) {
- // Reset the context routing pattern and params
- rctx.routePattern = ""
- rctx.routeParams.Keys = rctx.routeParams.Keys[:0]
- rctx.routeParams.Values = rctx.routeParams.Values[:0]
-
- // Find the routing handlers for the path
- rn := n.findRoute(rctx, method, path)
- if rn == nil {
- return nil, nil, nil
- }
-
- // Record the routing params in the request lifecycle
- rctx.URLParams.Keys = append(rctx.URLParams.Keys, rctx.routeParams.Keys...)
- rctx.URLParams.Values = append(rctx.URLParams.Values, rctx.routeParams.Values...)
-
- // Record the routing pattern in the request lifecycle
- if rn.endpoints[method].pattern != "" {
- rctx.routePattern = rn.endpoints[method].pattern
- rctx.RoutePatterns = append(rctx.RoutePatterns, rctx.routePattern)
- }
-
- return rn, rn.endpoints, rn.endpoints[method].handler
-}
-
-// Recursive edge traversal by checking all nodeTyp groups along the way.
-// It's like searching through a multi-dimensional radix trie.
-func (n *node) findRoute(rctx *Context, method methodTyp, path string) *node {
- nn := n
- search := path
-
- for t, nds := range nn.children {
- ntyp := nodeTyp(t)
- if len(nds) == 0 {
- continue
- }
-
- var xn *node
- xsearch := search
-
- var label byte
- if search != "" {
- label = search[0]
- }
-
- switch ntyp {
- case ntStatic:
- xn = nds.findEdge(label)
- if xn == nil || !strings.HasPrefix(xsearch, xn.prefix) {
- continue
- }
- xsearch = xsearch[len(xn.prefix):]
-
- case ntParam, ntRegexp:
- // short-circuit and return no matching route for empty param values
- if xsearch == "" {
- continue
- }
-
- // serially loop through each node grouped by the tail delimiter
- for idx := 0; idx < len(nds); idx++ {
- xn = nds[idx]
-
- // label for param nodes is the delimiter byte
- p := strings.IndexByte(xsearch, xn.tail)
-
- if p < 0 {
- if xn.tail == '/' {
- p = len(xsearch)
- } else {
- continue
- }
- } else if ntyp == ntRegexp && p == 0 {
- continue
- }
-
- if ntyp == ntRegexp && xn.rex != nil {
- if !xn.rex.MatchString(xsearch[:p]) {
- continue
- }
- } else if strings.IndexByte(xsearch[:p], '/') != -1 {
- // avoid a match across path segments
- continue
- }
-
- prevlen := len(rctx.routeParams.Values)
- rctx.routeParams.Values = append(rctx.routeParams.Values, xsearch[:p])
- xsearch = xsearch[p:]
-
- if len(xsearch) == 0 {
- if xn.isLeaf() {
- h := xn.endpoints[method]
- if h != nil && h.handler != nil {
- rctx.routeParams.Keys = append(rctx.routeParams.Keys, h.paramKeys...)
- return xn
- }
-
- // flag that the routing context found a route, but not a corresponding
- // supported method
- rctx.methodNotAllowed = true
- }
- }
-
- // recursively find the next node on this branch
- fin := xn.findRoute(rctx, method, xsearch)
- if fin != nil {
- return fin
- }
-
- // not found on this branch, reset vars
- rctx.routeParams.Values = rctx.routeParams.Values[:prevlen]
- xsearch = search
- }
-
- rctx.routeParams.Values = append(rctx.routeParams.Values, "")
-
- default:
- // catch-all nodes
- rctx.routeParams.Values = append(rctx.routeParams.Values, search)
- xn = nds[0]
- xsearch = ""
- }
-
- if xn == nil {
- continue
- }
-
- // did we find it yet?
- if len(xsearch) == 0 {
- if xn.isLeaf() {
- h := xn.endpoints[method]
- if h != nil && h.handler != nil {
- rctx.routeParams.Keys = append(rctx.routeParams.Keys, h.paramKeys...)
- return xn
- }
-
- // flag that the routing context found a route, but not a corresponding
- // supported method
- rctx.methodNotAllowed = true
- }
- }
-
- // recursively find the next node..
- fin := xn.findRoute(rctx, method, xsearch)
- if fin != nil {
- return fin
- }
-
- // Did not find final handler, let's remove the param here if it was set
- if xn.typ > ntStatic {
- if len(rctx.routeParams.Values) > 0 {
- rctx.routeParams.Values = rctx.routeParams.Values[:len(rctx.routeParams.Values)-1]
- }
- }
-
- }
-
- return nil
-}
-
-func (n *node) findEdge(ntyp nodeTyp, label byte) *node {
- nds := n.children[ntyp]
- num := len(nds)
- idx := 0
-
- switch ntyp {
- case ntStatic, ntParam, ntRegexp:
- i, j := 0, num-1
- for i <= j {
- idx = i + (j-i)/2
- if label > nds[idx].label {
- i = idx + 1
- } else if label < nds[idx].label {
- j = idx - 1
- } else {
- i = num // breaks cond
- }
- }
- if nds[idx].label != label {
- return nil
- }
- return nds[idx]
-
- default: // catch all
- return nds[idx]
- }
-}
-
-func (n *node) isLeaf() bool {
- return n.endpoints != nil
-}
-
-func (n *node) findPattern(pattern string) bool {
- nn := n
- for _, nds := range nn.children {
- if len(nds) == 0 {
- continue
- }
-
- n = nn.findEdge(nds[0].typ, pattern[0])
- if n == nil {
- continue
- }
-
- var idx int
- var xpattern string
-
- switch n.typ {
- case ntStatic:
- idx = longestPrefix(pattern, n.prefix)
- if idx < len(n.prefix) {
- continue
- }
-
- case ntParam, ntRegexp:
- idx = strings.IndexByte(pattern, '}') + 1
-
- case ntCatchAll:
- idx = longestPrefix(pattern, "*")
-
- default:
- panic("chi: unknown node type")
- }
-
- xpattern = pattern[idx:]
- if len(xpattern) == 0 {
- return true
- }
-
- return n.findPattern(xpattern)
- }
- return false
-}
-
-func (n *node) routes() []Route {
- rts := []Route{}
-
- n.walk(func(eps endpoints, subroutes Routes) bool {
- if eps[mSTUB] != nil && eps[mSTUB].handler != nil && subroutes == nil {
- return false
- }
-
- // Group methodHandlers by unique patterns
- pats := make(map[string]endpoints)
-
- for mt, h := range eps {
- if h.pattern == "" {
- continue
- }
- p, ok := pats[h.pattern]
- if !ok {
- p = endpoints{}
- pats[h.pattern] = p
- }
- p[mt] = h
- }
-
- for p, mh := range pats {
- hs := make(map[string]http.Handler)
- if mh[mALL] != nil && mh[mALL].handler != nil {
- hs["*"] = mh[mALL].handler
- }
-
- for mt, h := range mh {
- if h.handler == nil {
- continue
- }
- m := methodTypString(mt)
- if m == "" {
- continue
- }
- hs[m] = h.handler
- }
-
- rt := Route{p, hs, subroutes}
- rts = append(rts, rt)
- }
-
- return false
- })
-
- return rts
-}
-
-func (n *node) walk(fn func(eps endpoints, subroutes Routes) bool) bool {
- // Visit the leaf values if any
- if (n.endpoints != nil || n.subroutes != nil) && fn(n.endpoints, n.subroutes) {
- return true
- }
-
- // Recurse on the children
- for _, ns := range n.children {
- for _, cn := range ns {
- if cn.walk(fn) {
- return true
- }
- }
- }
- return false
-}
-
-// patNextSegment returns the next segment details from a pattern:
-// node type, param key, regexp string, param tail byte, param starting index, param ending index
-func patNextSegment(pattern string) (nodeTyp, string, string, byte, int, int) {
- ps := strings.Index(pattern, "{")
- ws := strings.Index(pattern, "*")
-
- if ps < 0 && ws < 0 {
- return ntStatic, "", "", 0, 0, len(pattern) // we return the entire thing
- }
-
- // Sanity check
- if ps >= 0 && ws >= 0 && ws < ps {
- panic("chi: wildcard '*' must be the last pattern in a route, otherwise use a '{param}'")
- }
-
- var tail byte = '/' // Default endpoint tail to / byte
-
- if ps >= 0 {
- // Param/Regexp pattern is next
- nt := ntParam
-
- // Read to closing } taking into account opens and closes in curl count (cc)
- cc := 0
- pe := ps
- for i, c := range pattern[ps:] {
- if c == '{' {
- cc++
- } else if c == '}' {
- cc--
- if cc == 0 {
- pe = ps + i
- break
- }
- }
- }
- if pe == ps {
- panic("chi: route param closing delimiter '}' is missing")
- }
-
- key := pattern[ps+1 : pe]
- pe++ // set end to next position
-
- if pe < len(pattern) {
- tail = pattern[pe]
- }
-
- var rexpat string
- if idx := strings.Index(key, ":"); idx >= 0 {
- nt = ntRegexp
- rexpat = key[idx+1:]
- key = key[:idx]
- }
-
- if len(rexpat) > 0 {
- if rexpat[0] != '^' {
- rexpat = "^" + rexpat
- }
- if rexpat[len(rexpat)-1] != '$' {
- rexpat += "$"
- }
- }
-
- return nt, key, rexpat, tail, ps, pe
- }
-
- // Wildcard pattern as finale
- if ws < len(pattern)-1 {
- panic("chi: wildcard '*' must be the last value in a route. trim trailing text or use a '{param}' instead")
- }
- return ntCatchAll, "*", "", 0, ws, len(pattern)
-}
-
-func patParamKeys(pattern string) []string {
- pat := pattern
- paramKeys := []string{}
- for {
- ptyp, paramKey, _, _, _, e := patNextSegment(pat)
- if ptyp == ntStatic {
- return paramKeys
- }
- for i := 0; i < len(paramKeys); i++ {
- if paramKeys[i] == paramKey {
- panic(fmt.Sprintf("chi: routing pattern '%s' contains duplicate param key, '%s'", pattern, paramKey))
- }
- }
- paramKeys = append(paramKeys, paramKey)
- pat = pat[e:]
- }
-}
-
-// longestPrefix finds the length of the shared prefix
-// of two strings
-func longestPrefix(k1, k2 string) int {
- max := len(k1)
- if l := len(k2); l < max {
- max = l
- }
- var i int
- for i = 0; i < max; i++ {
- if k1[i] != k2[i] {
- break
- }
- }
- return i
-}
-
-func methodTypString(method methodTyp) string {
- for s, t := range methodMap {
- if method == t {
- return s
- }
- }
- return ""
-}
-
-type nodes []*node
-
-// Sort the list of nodes by label
-func (ns nodes) Sort() { sort.Sort(ns); ns.tailSort() }
-func (ns nodes) Len() int { return len(ns) }
-func (ns nodes) Swap(i, j int) { ns[i], ns[j] = ns[j], ns[i] }
-func (ns nodes) Less(i, j int) bool { return ns[i].label < ns[j].label }
-
-// tailSort pushes nodes with '/' as the tail to the end of the list for param nodes.
-// The list order determines the traversal order.
-func (ns nodes) tailSort() {
- for i := len(ns) - 1; i >= 0; i-- {
- if ns[i].typ > ntStatic && ns[i].tail == '/' {
- ns.Swap(i, len(ns)-1)
- return
- }
- }
-}
-
-func (ns nodes) findEdge(label byte) *node {
- num := len(ns)
- idx := 0
- i, j := 0, num-1
- for i <= j {
- idx = i + (j-i)/2
- if label > ns[idx].label {
- i = idx + 1
- } else if label < ns[idx].label {
- j = idx - 1
- } else {
- i = num // breaks cond
- }
- }
- if ns[idx].label != label {
- return nil
- }
- return ns[idx]
-}
-
-// Route describes the details of a routing handler.
-// Handlers map key is an HTTP method
-type Route struct {
- Pattern string
- Handlers map[string]http.Handler
- SubRoutes Routes
-}
-
-// WalkFunc is the type of the function called for each method and route visited by Walk.
-type WalkFunc func(method string, route string, handler http.Handler, middlewares ...func(http.Handler) http.Handler) error
-
-// Walk walks any router tree that implements Routes interface.
-func Walk(r Routes, walkFn WalkFunc) error {
- return walk(r, walkFn, "")
-}
-
-func walk(r Routes, walkFn WalkFunc, parentRoute string, parentMw ...func(http.Handler) http.Handler) error {
- for _, route := range r.Routes() {
- mws := make([]func(http.Handler) http.Handler, len(parentMw))
- copy(mws, parentMw)
- mws = append(mws, r.Middlewares()...)
-
- if route.SubRoutes != nil {
- if err := walk(route.SubRoutes, walkFn, parentRoute+route.Pattern, mws...); err != nil {
- return err
- }
- continue
- }
-
- for method, handler := range route.Handlers {
- if method == "*" {
- // Ignore a "catchAll" method, since we pass down all the specific methods for each route.
- continue
- }
-
- fullRoute := parentRoute + route.Pattern
- fullRoute = strings.Replace(fullRoute, "/*/", "/", -1)
-
- if chain, ok := handler.(*ChainHandler); ok {
- if err := walkFn(method, fullRoute, chain.Endpoint, append(mws, chain.Middlewares...)...); err != nil {
- return err
- }
- } else {
- if err := walkFn(method, fullRoute, handler, mws...); err != nil {
- return err
- }
- }
- }
- }
-
- return nil
-}
+package chi
+
+// Radix tree implementation below is a based on the original work by
+// Armon Dadgar in https://github.com/armon/go-radix/blob/master/radix.go
+// (MIT licensed). It's been heavily modified for use as a HTTP routing tree.
+
+import (
+ "fmt"
+ "net/http"
+ "regexp"
+ "sort"
+ "strconv"
+ "strings"
+)
+
+type methodTyp int
+
+const (
+ mSTUB methodTyp = 1 << iota
+ mCONNECT
+ mDELETE
+ mGET
+ mHEAD
+ mOPTIONS
+ mPATCH
+ mPOST
+ mPUT
+ mTRACE
+)
+
+var mALL = mCONNECT | mDELETE | mGET | mHEAD |
+ mOPTIONS | mPATCH | mPOST | mPUT | mTRACE
+
+var methodMap = map[string]methodTyp{
+ http.MethodConnect: mCONNECT,
+ http.MethodDelete: mDELETE,
+ http.MethodGet: mGET,
+ http.MethodHead: mHEAD,
+ http.MethodOptions: mOPTIONS,
+ http.MethodPatch: mPATCH,
+ http.MethodPost: mPOST,
+ http.MethodPut: mPUT,
+ http.MethodTrace: mTRACE,
+}
+
+// RegisterMethod adds support for custom HTTP method handlers, available
+// via Router#Method and Router#MethodFunc
+func RegisterMethod(method string) {
+ if method == "" {
+ return
+ }
+ method = strings.ToUpper(method)
+ if _, ok := methodMap[method]; ok {
+ return
+ }
+ n := len(methodMap)
+ if n > strconv.IntSize-2 {
+ panic(fmt.Sprintf("chi: max number of methods reached (%d)", strconv.IntSize))
+ }
+ mt := methodTyp(2 << n)
+ methodMap[method] = mt
+ mALL |= mt
+}
+
+type nodeTyp uint8
+
+const (
+ ntStatic nodeTyp = iota // /home
+ ntRegexp // /{id:[0-9]+}
+ ntParam // /{user}
+ ntCatchAll // /api/v1/*
+)
+
+type node struct {
+ // node type: static, regexp, param, catchAll
+ typ nodeTyp
+
+ // first byte of the prefix
+ label byte
+
+ // first byte of the child prefix
+ tail byte
+
+ // prefix is the common prefix we ignore
+ prefix string
+
+ // regexp matcher for regexp nodes
+ rex *regexp.Regexp
+
+ // HTTP handler endpoints on the leaf node
+ endpoints endpoints
+
+ // subroutes on the leaf node
+ subroutes Routes
+
+ // child nodes should be stored in-order for iteration,
+ // in groups of the node type.
+ children [ntCatchAll + 1]nodes
+}
+
+// endpoints is a mapping of http method constants to handlers
+// for a given route.
+type endpoints map[methodTyp]*endpoint
+
+type endpoint struct {
+ // endpoint handler
+ handler http.Handler
+
+ // pattern is the routing pattern for handler nodes
+ pattern string
+
+ // parameter keys recorded on handler nodes
+ paramKeys []string
+}
+
+func (s endpoints) Value(method methodTyp) *endpoint {
+ mh, ok := s[method]
+ if !ok {
+ mh = &endpoint{}
+ s[method] = mh
+ }
+ return mh
+}
+
+func (n *node) InsertRoute(method methodTyp, pattern string, handler http.Handler) *node {
+ var parent *node
+ search := pattern
+
+ for {
+ // Handle key exhaustion
+ if len(search) == 0 {
+ // Insert or update the node's leaf handler
+ n.setEndpoint(method, handler, pattern)
+ return n
+ }
+
+ // We're going to be searching for a wild node next,
+ // in this case, we need to get the tail
+ var label = search[0]
+ var segTail byte
+ var segEndIdx int
+ var segTyp nodeTyp
+ var segRexpat string
+ if label == '{' || label == '*' {
+ segTyp, _, segRexpat, segTail, _, segEndIdx = patNextSegment(search)
+ }
+
+ var prefix string
+ if segTyp == ntRegexp {
+ prefix = segRexpat
+ }
+
+ // Look for the edge to attach to
+ parent = n
+ n = n.getEdge(segTyp, label, segTail, prefix)
+
+ // No edge, create one
+ if n == nil {
+ child := &node{label: label, tail: segTail, prefix: search}
+ hn := parent.addChild(child, search)
+ hn.setEndpoint(method, handler, pattern)
+
+ return hn
+ }
+
+ // Found an edge to match the pattern
+
+ if n.typ > ntStatic {
+ // We found a param node, trim the param from the search path and continue.
+ // This param/wild pattern segment would already be on the tree from a previous
+ // call to addChild when creating a new node.
+ search = search[segEndIdx:]
+ continue
+ }
+
+ // Static nodes fall below here.
+ // Determine longest prefix of the search key on match.
+ commonPrefix := longestPrefix(search, n.prefix)
+ if commonPrefix == len(n.prefix) {
+ // the common prefix is as long as the current node's prefix we're attempting to insert.
+ // keep the search going.
+ search = search[commonPrefix:]
+ continue
+ }
+
+ // Split the node
+ child := &node{
+ typ: ntStatic,
+ prefix: search[:commonPrefix],
+ }
+ parent.replaceChild(search[0], segTail, child)
+
+ // Restore the existing node
+ n.label = n.prefix[commonPrefix]
+ n.prefix = n.prefix[commonPrefix:]
+ child.addChild(n, n.prefix)
+
+ // If the new key is a subset, set the method/handler on this node and finish.
+ search = search[commonPrefix:]
+ if len(search) == 0 {
+ child.setEndpoint(method, handler, pattern)
+ return child
+ }
+
+ // Create a new edge for the node
+ subchild := &node{
+ typ: ntStatic,
+ label: search[0],
+ prefix: search,
+ }
+ hn := child.addChild(subchild, search)
+ hn.setEndpoint(method, handler, pattern)
+ return hn
+ }
+}
+
+// addChild appends the new `child` node to the tree using the `pattern` as the trie key.
+// For a URL router like chi's, we split the static, param, regexp and wildcard segments
+// into different nodes. In addition, addChild will recursively call itself until every
+// pattern segment is added to the url pattern tree as individual nodes, depending on type.
+func (n *node) addChild(child *node, prefix string) *node {
+ search := prefix
+
+ // handler leaf node added to the tree is the child.
+ // this may be overridden later down the flow
+ hn := child
+
+ // Parse next segment
+ segTyp, _, segRexpat, segTail, segStartIdx, segEndIdx := patNextSegment(search)
+
+ // Add child depending on next up segment
+ switch segTyp {
+
+ case ntStatic:
+ // Search prefix is all static (that is, has no params in path)
+ // noop
+
+ default:
+ // Search prefix contains a param, regexp or wildcard
+
+ if segTyp == ntRegexp {
+ rex, err := regexp.Compile(segRexpat)
+ if err != nil {
+ panic(fmt.Sprintf("chi: invalid regexp pattern '%s' in route param", segRexpat))
+ }
+ child.prefix = segRexpat
+ child.rex = rex
+ }
+
+ if segStartIdx == 0 {
+ // Route starts with a param
+ child.typ = segTyp
+
+ if segTyp == ntCatchAll {
+ segStartIdx = -1
+ } else {
+ segStartIdx = segEndIdx
+ }
+ if segStartIdx < 0 {
+ segStartIdx = len(search)
+ }
+ child.tail = segTail // for params, we set the tail
+
+ if segStartIdx != len(search) {
+ // add static edge for the remaining part, split the end.
+ // its not possible to have adjacent param nodes, so its certainly
+ // going to be a static node next.
+
+ search = search[segStartIdx:] // advance search position
+
+ nn := &node{
+ typ: ntStatic,
+ label: search[0],
+ prefix: search,
+ }
+ hn = child.addChild(nn, search)
+ }
+
+ } else if segStartIdx > 0 {
+ // Route has some param
+
+ // starts with a static segment
+ child.typ = ntStatic
+ child.prefix = search[:segStartIdx]
+ child.rex = nil
+
+ // add the param edge node
+ search = search[segStartIdx:]
+
+ nn := &node{
+ typ: segTyp,
+ label: search[0],
+ tail: segTail,
+ }
+ hn = child.addChild(nn, search)
+
+ }
+ }
+
+ n.children[child.typ] = append(n.children[child.typ], child)
+ n.children[child.typ].Sort()
+ return hn
+}
+
+func (n *node) replaceChild(label, tail byte, child *node) {
+ for i := 0; i < len(n.children[child.typ]); i++ {
+ if n.children[child.typ][i].label == label && n.children[child.typ][i].tail == tail {
+ n.children[child.typ][i] = child
+ n.children[child.typ][i].label = label
+ n.children[child.typ][i].tail = tail
+ return
+ }
+ }
+ panic("chi: replacing missing child")
+}
+
+func (n *node) getEdge(ntyp nodeTyp, label, tail byte, prefix string) *node {
+ nds := n.children[ntyp]
+ for i := 0; i < len(nds); i++ {
+ if nds[i].label == label && nds[i].tail == tail {
+ if ntyp == ntRegexp && nds[i].prefix != prefix {
+ continue
+ }
+ return nds[i]
+ }
+ }
+ return nil
+}
+
+func (n *node) setEndpoint(method methodTyp, handler http.Handler, pattern string) {
+ // Set the handler for the method type on the node
+ if n.endpoints == nil {
+ n.endpoints = make(endpoints)
+ }
+
+ paramKeys := patParamKeys(pattern)
+
+ if method&mSTUB == mSTUB {
+ n.endpoints.Value(mSTUB).handler = handler
+ }
+ if method&mALL == mALL {
+ h := n.endpoints.Value(mALL)
+ h.handler = handler
+ h.pattern = pattern
+ h.paramKeys = paramKeys
+ for _, m := range methodMap {
+ h := n.endpoints.Value(m)
+ h.handler = handler
+ h.pattern = pattern
+ h.paramKeys = paramKeys
+ }
+ } else {
+ h := n.endpoints.Value(method)
+ h.handler = handler
+ h.pattern = pattern
+ h.paramKeys = paramKeys
+ }
+}
+
+func (n *node) FindRoute(rctx *Context, method methodTyp, path string) (*node, endpoints, http.Handler) {
+ // Reset the context routing pattern and params
+ rctx.routePattern = ""
+ rctx.routeParams.Keys = rctx.routeParams.Keys[:0]
+ rctx.routeParams.Values = rctx.routeParams.Values[:0]
+
+ // Find the routing handlers for the path
+ rn := n.findRoute(rctx, method, path)
+ if rn == nil {
+ return nil, nil, nil
+ }
+
+ // Record the routing params in the request lifecycle
+ rctx.URLParams.Keys = append(rctx.URLParams.Keys, rctx.routeParams.Keys...)
+ rctx.URLParams.Values = append(rctx.URLParams.Values, rctx.routeParams.Values...)
+
+ // Record the routing pattern in the request lifecycle
+ if rn.endpoints[method].pattern != "" {
+ rctx.routePattern = rn.endpoints[method].pattern
+ rctx.RoutePatterns = append(rctx.RoutePatterns, rctx.routePattern)
+ }
+
+ return rn, rn.endpoints, rn.endpoints[method].handler
+}
+
+// Recursive edge traversal by checking all nodeTyp groups along the way.
+// It's like searching through a multi-dimensional radix trie.
+func (n *node) findRoute(rctx *Context, method methodTyp, path string) *node {
+ nn := n
+ search := path
+
+ for t, nds := range nn.children {
+ ntyp := nodeTyp(t)
+ if len(nds) == 0 {
+ continue
+ }
+
+ var xn *node
+ xsearch := search
+
+ var label byte
+ if search != "" {
+ label = search[0]
+ }
+
+ switch ntyp {
+ case ntStatic:
+ xn = nds.findEdge(label)
+ if xn == nil || !strings.HasPrefix(xsearch, xn.prefix) {
+ continue
+ }
+ xsearch = xsearch[len(xn.prefix):]
+
+ case ntParam, ntRegexp:
+ // short-circuit and return no matching route for empty param values
+ if xsearch == "" {
+ continue
+ }
+
+ // serially loop through each node grouped by the tail delimiter
+ for idx := 0; idx < len(nds); idx++ {
+ xn = nds[idx]
+
+ // label for param nodes is the delimiter byte
+ p := strings.IndexByte(xsearch, xn.tail)
+
+ if p < 0 {
+ if xn.tail == '/' {
+ p = len(xsearch)
+ } else {
+ continue
+ }
+ } else if ntyp == ntRegexp && p == 0 {
+ continue
+ }
+
+ if ntyp == ntRegexp && xn.rex != nil {
+ if !xn.rex.MatchString(xsearch[:p]) {
+ continue
+ }
+ } else if strings.IndexByte(xsearch[:p], '/') != -1 {
+ // avoid a match across path segments
+ continue
+ }
+
+ prevlen := len(rctx.routeParams.Values)
+ rctx.routeParams.Values = append(rctx.routeParams.Values, xsearch[:p])
+ xsearch = xsearch[p:]
+
+ if len(xsearch) == 0 {
+ if xn.isLeaf() {
+ h := xn.endpoints[method]
+ if h != nil && h.handler != nil {
+ rctx.routeParams.Keys = append(rctx.routeParams.Keys, h.paramKeys...)
+ return xn
+ }
+
+ // flag that the routing context found a route, but not a corresponding
+ // supported method
+ rctx.methodNotAllowed = true
+ }
+ }
+
+ // recursively find the next node on this branch
+ fin := xn.findRoute(rctx, method, xsearch)
+ if fin != nil {
+ return fin
+ }
+
+ // not found on this branch, reset vars
+ rctx.routeParams.Values = rctx.routeParams.Values[:prevlen]
+ xsearch = search
+ }
+
+ rctx.routeParams.Values = append(rctx.routeParams.Values, "")
+
+ default:
+ // catch-all nodes
+ rctx.routeParams.Values = append(rctx.routeParams.Values, search)
+ xn = nds[0]
+ xsearch = ""
+ }
+
+ if xn == nil {
+ continue
+ }
+
+ // did we find it yet?
+ if len(xsearch) == 0 {
+ if xn.isLeaf() {
+ h := xn.endpoints[method]
+ if h != nil && h.handler != nil {
+ rctx.routeParams.Keys = append(rctx.routeParams.Keys, h.paramKeys...)
+ return xn
+ }
+
+ // flag that the routing context found a route, but not a corresponding
+ // supported method
+ rctx.methodNotAllowed = true
+ }
+ }
+
+ // recursively find the next node..
+ fin := xn.findRoute(rctx, method, xsearch)
+ if fin != nil {
+ return fin
+ }
+
+ // Did not find final handler, let's remove the param here if it was set
+ if xn.typ > ntStatic {
+ if len(rctx.routeParams.Values) > 0 {
+ rctx.routeParams.Values = rctx.routeParams.Values[:len(rctx.routeParams.Values)-1]
+ }
+ }
+
+ }
+
+ return nil
+}
+
+func (n *node) findEdge(ntyp nodeTyp, label byte) *node {
+ nds := n.children[ntyp]
+ num := len(nds)
+ idx := 0
+
+ switch ntyp {
+ case ntStatic, ntParam, ntRegexp:
+ i, j := 0, num-1
+ for i <= j {
+ idx = i + (j-i)/2
+ if label > nds[idx].label {
+ i = idx + 1
+ } else if label < nds[idx].label {
+ j = idx - 1
+ } else {
+ i = num // breaks cond
+ }
+ }
+ if nds[idx].label != label {
+ return nil
+ }
+ return nds[idx]
+
+ default: // catch all
+ return nds[idx]
+ }
+}
+
+func (n *node) isLeaf() bool {
+ return n.endpoints != nil
+}
+
+func (n *node) findPattern(pattern string) bool {
+ nn := n
+ for _, nds := range nn.children {
+ if len(nds) == 0 {
+ continue
+ }
+
+ n = nn.findEdge(nds[0].typ, pattern[0])
+ if n == nil {
+ continue
+ }
+
+ var idx int
+ var xpattern string
+
+ switch n.typ {
+ case ntStatic:
+ idx = longestPrefix(pattern, n.prefix)
+ if idx < len(n.prefix) {
+ continue
+ }
+
+ case ntParam, ntRegexp:
+ idx = strings.IndexByte(pattern, '}') + 1
+
+ case ntCatchAll:
+ idx = longestPrefix(pattern, "*")
+
+ default:
+ panic("chi: unknown node type")
+ }
+
+ xpattern = pattern[idx:]
+ if len(xpattern) == 0 {
+ return true
+ }
+
+ return n.findPattern(xpattern)
+ }
+ return false
+}
+
+func (n *node) routes() []Route {
+ rts := []Route{}
+
+ n.walk(func(eps endpoints, subroutes Routes) bool {
+ if eps[mSTUB] != nil && eps[mSTUB].handler != nil && subroutes == nil {
+ return false
+ }
+
+ // Group methodHandlers by unique patterns
+ pats := make(map[string]endpoints)
+
+ for mt, h := range eps {
+ if h.pattern == "" {
+ continue
+ }
+ p, ok := pats[h.pattern]
+ if !ok {
+ p = endpoints{}
+ pats[h.pattern] = p
+ }
+ p[mt] = h
+ }
+
+ for p, mh := range pats {
+ hs := make(map[string]http.Handler)
+ if mh[mALL] != nil && mh[mALL].handler != nil {
+ hs["*"] = mh[mALL].handler
+ }
+
+ for mt, h := range mh {
+ if h.handler == nil {
+ continue
+ }
+ m := methodTypString(mt)
+ if m == "" {
+ continue
+ }
+ hs[m] = h.handler
+ }
+
+ rt := Route{p, hs, subroutes}
+ rts = append(rts, rt)
+ }
+
+ return false
+ })
+
+ return rts
+}
+
+func (n *node) walk(fn func(eps endpoints, subroutes Routes) bool) bool {
+ // Visit the leaf values if any
+ if (n.endpoints != nil || n.subroutes != nil) && fn(n.endpoints, n.subroutes) {
+ return true
+ }
+
+ // Recurse on the children
+ for _, ns := range n.children {
+ for _, cn := range ns {
+ if cn.walk(fn) {
+ return true
+ }
+ }
+ }
+ return false
+}
+
+// patNextSegment returns the next segment details from a pattern:
+// node type, param key, regexp string, param tail byte, param starting index, param ending index
+func patNextSegment(pattern string) (nodeTyp, string, string, byte, int, int) {
+ ps := strings.Index(pattern, "{")
+ ws := strings.Index(pattern, "*")
+
+ if ps < 0 && ws < 0 {
+ return ntStatic, "", "", 0, 0, len(pattern) // we return the entire thing
+ }
+
+ // Sanity check
+ if ps >= 0 && ws >= 0 && ws < ps {
+ panic("chi: wildcard '*' must be the last pattern in a route, otherwise use a '{param}'")
+ }
+
+ var tail byte = '/' // Default endpoint tail to / byte
+
+ if ps >= 0 {
+ // Param/Regexp pattern is next
+ nt := ntParam
+
+ // Read to closing } taking into account opens and closes in curl count (cc)
+ cc := 0
+ pe := ps
+ for i, c := range pattern[ps:] {
+ if c == '{' {
+ cc++
+ } else if c == '}' {
+ cc--
+ if cc == 0 {
+ pe = ps + i
+ break
+ }
+ }
+ }
+ if pe == ps {
+ panic("chi: route param closing delimiter '}' is missing")
+ }
+
+ key := pattern[ps+1 : pe]
+ pe++ // set end to next position
+
+ if pe < len(pattern) {
+ tail = pattern[pe]
+ }
+
+ var rexpat string
+ if idx := strings.Index(key, ":"); idx >= 0 {
+ nt = ntRegexp
+ rexpat = key[idx+1:]
+ key = key[:idx]
+ }
+
+ if len(rexpat) > 0 {
+ if rexpat[0] != '^' {
+ rexpat = "^" + rexpat
+ }
+ if rexpat[len(rexpat)-1] != '$' {
+ rexpat += "$"
+ }
+ }
+
+ return nt, key, rexpat, tail, ps, pe
+ }
+
+ // Wildcard pattern as finale
+ if ws < len(pattern)-1 {
+ panic("chi: wildcard '*' must be the last value in a route. trim trailing text or use a '{param}' instead")
+ }
+ return ntCatchAll, "*", "", 0, ws, len(pattern)
+}
+
+func patParamKeys(pattern string) []string {
+ pat := pattern
+ paramKeys := []string{}
+ for {
+ ptyp, paramKey, _, _, _, e := patNextSegment(pat)
+ if ptyp == ntStatic {
+ return paramKeys
+ }
+ for i := 0; i < len(paramKeys); i++ {
+ if paramKeys[i] == paramKey {
+ panic(fmt.Sprintf("chi: routing pattern '%s' contains duplicate param key, '%s'", pattern, paramKey))
+ }
+ }
+ paramKeys = append(paramKeys, paramKey)
+ pat = pat[e:]
+ }
+}
+
+// longestPrefix finds the length of the shared prefix
+// of two strings
+func longestPrefix(k1, k2 string) int {
+ max := len(k1)
+ if l := len(k2); l < max {
+ max = l
+ }
+ var i int
+ for i = 0; i < max; i++ {
+ if k1[i] != k2[i] {
+ break
+ }
+ }
+ return i
+}
+
+func methodTypString(method methodTyp) string {
+ for s, t := range methodMap {
+ if method == t {
+ return s
+ }
+ }
+ return ""
+}
+
+type nodes []*node
+
+// Sort the list of nodes by label
+func (ns nodes) Sort() { sort.Sort(ns); ns.tailSort() }
+func (ns nodes) Len() int { return len(ns) }
+func (ns nodes) Swap(i, j int) { ns[i], ns[j] = ns[j], ns[i] }
+func (ns nodes) Less(i, j int) bool { return ns[i].label < ns[j].label }
+
+// tailSort pushes nodes with '/' as the tail to the end of the list for param nodes.
+// The list order determines the traversal order.
+func (ns nodes) tailSort() {
+ for i := len(ns) - 1; i >= 0; i-- {
+ if ns[i].typ > ntStatic && ns[i].tail == '/' {
+ ns.Swap(i, len(ns)-1)
+ return
+ }
+ }
+}
+
+func (ns nodes) findEdge(label byte) *node {
+ num := len(ns)
+ idx := 0
+ i, j := 0, num-1
+ for i <= j {
+ idx = i + (j-i)/2
+ if label > ns[idx].label {
+ i = idx + 1
+ } else if label < ns[idx].label {
+ j = idx - 1
+ } else {
+ i = num // breaks cond
+ }
+ }
+ if ns[idx].label != label {
+ return nil
+ }
+ return ns[idx]
+}
+
+// Route describes the details of a routing handler.
+// Handlers map key is an HTTP method
+type Route struct {
+ Pattern string
+ Handlers map[string]http.Handler
+ SubRoutes Routes
+}
+
+// WalkFunc is the type of the function called for each method and route visited by Walk.
+type WalkFunc func(method string, route string, handler http.Handler, middlewares ...func(http.Handler) http.Handler) error
+
+// Walk walks any router tree that implements Routes interface.
+func Walk(r Routes, walkFn WalkFunc) error {
+ return walk(r, walkFn, "")
+}
+
+func walk(r Routes, walkFn WalkFunc, parentRoute string, parentMw ...func(http.Handler) http.Handler) error {
+ for _, route := range r.Routes() {
+ mws := make([]func(http.Handler) http.Handler, len(parentMw))
+ copy(mws, parentMw)
+ mws = append(mws, r.Middlewares()...)
+
+ if route.SubRoutes != nil {
+ if err := walk(route.SubRoutes, walkFn, parentRoute+route.Pattern, mws...); err != nil {
+ return err
+ }
+ continue
+ }
+
+ for method, handler := range route.Handlers {
+ if method == "*" {
+ // Ignore a "catchAll" method, since we pass down all the specific methods for each route.
+ continue
+ }
+
+ fullRoute := parentRoute + route.Pattern
+ fullRoute = strings.Replace(fullRoute, "/*/", "/", -1)
+
+ if chain, ok := handler.(*ChainHandler); ok {
+ if err := walkFn(method, fullRoute, chain.Endpoint, append(mws, chain.Middlewares...)...); err != nil {
+ return err
+ }
+ } else {
+ if err := walkFn(method, fullRoute, handler, mws...); err != nil {
+ return err
+ }
+ }
+ }
+ }
+
+ return nil
+}
diff --git a/vendor/github.com/go-chi/cors/LICENSE b/vendor/github.com/go-chi/cors/LICENSE
index aee6182f9a..4625ccdb6b 100644
--- a/vendor/github.com/go-chi/cors/LICENSE
+++ b/vendor/github.com/go-chi/cors/LICENSE
@@ -1,21 +1,21 @@
-Copyright (c) 2014 Olivier Poitrey =p for i =p for i =p for i =p for i