Make file package's struct marshallable

Author: antonmedv

internal/file/error.go

@@ -31,15 +31,15 @@ func (e *Error) Format(source *Source) string {
 	var result = fmt.Sprintf(
 		"%s (%d:%d)",
 		e.Message,
-		e.Location.Line(),
-		e.Location.Column()+1, // add one to the 0-based column for display
+		e.Location.Line,
+		e.Location.Column+1, // add one to the 0-based column for display
 	)
-	if snippet, found := source.Snippet(e.Location.Line()); found {
+	if snippet, found := source.Snippet(e.Location.Line); found {
 		snippet := strings.Replace(snippet, "\t", " ", -1)
 		srcLine := "\n | " + snippet
 		var bytes = []byte(snippet)
 		var indLine = "\n | "
-		for i := 0; i < e.Location.Column() && len(bytes) > 0; i++ {
+		for i := 0; i < e.Location.Column && len(bytes) > 0; i++ {
 			_, sz := utf8.DecodeRune(bytes)
 			bytes = bytes[sz:]
 			if sz > 1 {

internal/file/errors_test.go

@@ -8,12 +8,12 @@ import (
 func TestErrors(t *testing.T) {
 	source := NewSource("a.b\n&&arg(missing, paren")
 	errors := NewErrors(source)
-	errors.ReportError(NewLocation(1, 1), "No such field")
+	errors.ReportError(Location{Line: 1, Column: 1}, "No such field")
 	if len(errors.GetErrors()) != 1 {
 		t.Errorf("%s first error not recorded", t.Name())
 	}
 	errors.ReportError(
-		NewLocation(2, 20),
+		Location{Line: 2, Column: 20},
 		"syntax error, missing paren",
 	)
 	if len(errors.GetErrors()) != 2 {
@@ -35,7 +35,7 @@ func TestErrors(t *testing.T) {
 func TestErrors_WideAndNarrowCharacters(t *testing.T) {
 	source := NewSource("你好吗\n我b很好\n")
 	errors := NewErrors(source)
-	errors.ReportError(NewLocation(2, 3), "Unexpected character '好'")
+	errors.ReportError(Location{Line: 2, Column: 3}, "Unexpected character '好'")
 
 	got := errors.Error()
 	want := "Unexpected character '好' (2:4)\n" +
@@ -49,9 +49,9 @@ func TestErrors_WideAndNarrowCharacters(t *testing.T) {
 func TestErrors_WideAndNarrowCharacters_Emojis(t *testing.T) {
 	source := NewSource("      '😁' in ['😁', '😑', '😦'] && in.😁")
 	errors := NewErrors(source)
-	errors.ReportError(NewLocation(1, 32), "syntax error: extraneous input 'in' expecting {'[', '{', '(', '.', '-', '!', 'true', 'false', 'null', NUM_FLOAT, NUM_INT, NUM_UINT, STRING, BYTES, IDENTIFIER}")
-	errors.ReportError(NewLocation(1, 35), "syntax error: token recognition error at: '😁'")
-	errors.ReportError(NewLocation(1, 36), "syntax error: missing IDENTIFIER at '<EOF>'")
+	errors.ReportError(Location{Line: 1, Column: 32}, "syntax error: extraneous input 'in' expecting {'[', '{', '(', '.', '-', '!', 'true', 'false', 'null', NUM_FLOAT, NUM_INT, NUM_UINT, STRING, BYTES, IDENTIFIER}")
+	errors.ReportError(Location{Line: 1, Column: 35}, "syntax error: token recognition error at: '😁'")
+	errors.ReportError(Location{Line: 1, Column: 36}, "syntax error: missing IDENTIFIER at '<EOF>'")
 	got := errors.Error()
 	want := "syntax error: extraneous input 'in' expecting {'[', '{', '(', '.', '-', '!', 'true', 'false', 'null', NUM_FLOAT, NUM_INT, NUM_UINT, STRING, BYTES, IDENTIFIER} (1:33)\n" +
 		" |       '😁' in ['😁', '😑', '😦'] && in.😁\n" +

internal/file/location.go

@@ -1,27 +1,10 @@
 package file
 
 type Location struct {
-	line   int
-	column int
-}
-
-func NewLocation(line, column int) Location {
-	return Location{
-		line:   line,
-		column: column,
-	}
-}
-
-// Line returns the 1-based line of the location.
-func (l Location) Line() int {
-	return l.line
-}
-
-// Column returns the 0-based column number of the location.
-func (l Location) Column() int {
-	return l.column
+	Line   int // The 1-based line of the location.
+	Column int // The 0-based column number of the location.
 }
 
 func (l Location) Empty() bool {
-	return l.column == 0 && l.line == 0
+	return l.Column == 0 && l.Line == 0
 }

internal/file/source.go

@@ -1,6 +1,7 @@
 package file
 
 import (
+	"encoding/json"
 	"strings"
 	"unicode/utf8"
 )
@@ -11,18 +12,27 @@ type Source struct {
 }
 
 func NewSource(contents string) *Source {
-	// Compute line offsets up front as they are referred to frequently.
-	lines := strings.Split(contents, "\n")
-	offsets := make([]int32, len(lines))
-	var offset int32
-	for i, line := range lines {
-		offset = offset + int32(utf8.RuneCountInString(line)) + 1
-		offsets[int32(i)] = offset
+	s := &Source{
+		contents: []rune(contents),
 	}
-	return &Source{
-		contents:    []rune(contents),
-		lineOffsets: offsets,
+	s.updateOffsets()
+	return s
+}
+
+func (s *Source) MarshalJSON() ([]byte, error) {
+	return json.Marshal(s.contents)
+}
+
+func (s *Source) UnmarshalJSON(b []byte) error {
+	contents := make([]rune, 0)
+	err := json.Unmarshal(b, &contents)
+	if err != nil {
+		return err
 	}
+
+	s.contents = contents
+	s.updateOffsets()
+	return nil
 }
 
 func (s *Source) Content() string {
@@ -41,6 +51,18 @@ func (s *Source) Snippet(line int) (string, bool) {
 	return string(s.contents[charStart:]), true
 }
 
+// updateOffsets compute line offsets up front as they are referred to frequently.
+func (s *Source) updateOffsets() {
+	lines := strings.Split(string(s.contents), "\n")
+	offsets := make([]int32, len(lines))
+	var offset int32
+	for i, line := range lines {
+		offset = offset + int32(utf8.RuneCountInString(line)) + 1
+		offsets[int32(i)] = offset
+	}
+	s.lineOffsets = offsets
+}
+
 // findLineOffset returns the offset where the (1-indexed) line begins,
 // or false if line doesn't exist.
 func (s *Source) findLineOffset(line int) (int32, bool) {

internal/file/source_test.go

@@ -8,7 +8,7 @@ const (
 	unexpectedValue   = "%s got snippet '%v', want '%v'"
 	unexpectedSnippet = "%s got snippet '%s', want '%v'"
 	snippetNotFound   = "%s snippet not found, wanted '%v'"
-	snippetFound      = "%s snippet found at line %d, wanted none"
+	snippetFound      = "%s snippet found at Line %d, wanted none"
 )
 
 // TestStringSource_SnippetMultiline snippets of text from a multiline source.

parser/parser.go

@@ -407,7 +407,7 @@ func (p *parser) ExitClosureMemberDotExpression(ctx *gen.ClosureMemberDotExpress
 }
 
 func (p *parser) SyntaxError(recognizer antlr.Recognizer, offendingSymbol interface{}, line, column int, msg string, e antlr.RecognitionException) {
-	p.errors.ReportError(file.NewLocation(line, column), fmt.Sprintf("syntax error: %s", msg))
+	p.errors.ReportError(file.Location{Line: line, Column: column}, fmt.Sprintf("syntax error: %s", msg))
 }
 
 func (p *parser) ReportAmbiguity(_ antlr.Parser, _ *antlr.DFA, _, _ int, _ bool, _ *antlr.BitSet, _ antlr.ATNConfigSet) {
@@ -432,17 +432,17 @@ func unquotes(s string) string {
 
 func location(ctx antlr.ParserRuleContext) file.Location {
 	if ctx == nil {
-		return file.NewLocation(0, 0)
+		return file.Location{Line: 0, Column: 0}
 	}
 
 	token := ctx.GetStart()
 	if token == nil {
-		return file.NewLocation(0, 0)
+		return file.Location{Line: 0, Column: 0}
 	}
 
-	return file.NewLocation(token.GetLine(), token.GetColumn())
+	return file.Location{Line: token.GetLine(), Column: token.GetColumn()}
 }
 
 func locationToken(token antlr.Token) file.Location {
-	return file.NewLocation(token.GetLine(), token.GetColumn())
+	return file.Location{Line: token.GetLine(), Column: token.GetColumn()}
 }