Changelog

All notable changes will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

Renamed CustomLexerContext to LexCursor and separated it from the context.Context type.
Renamed ParserContext to ParseCursor and separated it from the context.Context type.

Refactored CustomLexer to add a new CustomLexerContext type that is passed to state functions. This context provides access to the underlying Lexer as well as additional helper methods for lexing.
Refactored Parser to add a new ParserContext type that is passed to state functions. This context provides access to the underlying Parser as well as additional helper methods for parsing.
Updated the CustomLexer to not return io.EOF from CustomLexer.Err. It should only return unexpected errors (#170).
Fixed an issue where the Filename field was not set on Position values returned by the CustomLexer and ScanningLexer (#169).

The EOF token emitted by the Lexer now includes the position where the EOF is encountered.
The Parser now includes NewNode and SetRoot methods. These methods are useful for parsers that need to build the parse tree themselves instead of using the default methods on the Parser.
The Lexer API has been completely redesigned. A Lexer interface was added and there are now two implementations: ScanningLexer and CustomLexer. ScanningLexer is based on text/scanner and can handle many use cases. CustomLexer allows for more custom lexing behavior to be implemented (#129).