tpl/internal: Sync go_templates

Closes #10411

tpl/internal/go_templates/texttemplate/parse/lex.go

@@ -111,31 +111,36 @@ type stateFn func(*lexer) stateFn
 
 // lexer holds the state of the scanner.
 type lexer struct {
-	name        string    // the name of the input; used only for error reports
-	input       string    // the string being scanned
-	leftDelim   string    // start of action
-	rightDelim  string    // end of action
-	emitComment bool      // emit itemComment tokens.
-	pos         Pos       // current position in the input
-	start       Pos       // start position of this item
-	width       Pos       // width of last rune read from input
-	items       chan item // channel of scanned items
-	parenDepth  int       // nesting depth of ( ) exprs
-	line        int       // 1+number of newlines seen
-	startLine   int       // start line of this item
-	breakOK     bool      // break keyword allowed
-	continueOK  bool      // continue keyword allowed
+	name         string // the name of the input; used only for error reports
+	input        string // the string being scanned
+	leftDelim    string // start of action marker
+	rightDelim   string // end of action marker
+	pos          Pos    // current position in the input
+	start        Pos    // start position of this item
+	atEOF        bool   // we have hit the end of input and returned eof
+	parenDepth   int    // nesting depth of ( ) exprs
+	line         int    // 1+number of newlines seen
+	startLine    int    // start line of this item
+	item         item   // item to return to parser
+	insideAction bool   // are we inside an action?
+	options      lexOptions
+}
+
+// lexOptions control behavior of the lexer. All default to false.
+type lexOptions struct {
+	emitComment bool // emit itemComment tokens.
+	breakOK     bool // break keyword allowed
+	continueOK  bool // continue keyword allowed
 }
 
 // next returns the next rune in the input.
 func (l *lexer) next() rune {
 	if int(l.pos) >= len(l.input) {
-		l.width = 0
+		l.atEOF = true
 		return eof
 	}
 	r, w := utf8.DecodeRuneInString(l.input[l.pos:])
-	l.width = Pos(w)
-	l.pos += l.width
+	l.pos += Pos(w)
 	if r == '\n' {
 		l.line++
 	}
@@ -149,23 +154,41 @@ func (l *lexer) peek() rune {
 	return r
 }
 
-// backup steps back one rune. Can only be called once per call of next.
+// backup steps back one rune.
 func (l *lexer) backup() {
-	l.pos -= l.width
-	// Correct newline count.
-	if l.width == 1 && l.input[l.pos] == '\n' {
-		l.line--
+	if !l.atEOF && l.pos > 0 {
+		r, w := utf8.DecodeLastRuneInString(l.input[:l.pos])
+		l.pos -= Pos(w)
+		// Correct newline count.
+		if r == '\n' {
+			l.line--
+		}
 	}
 }
 
-// emit passes an item back to the client.
-func (l *lexer) emit(t itemType) {
-	l.items <- item{t, l.start, l.input[l.start:l.pos], l.startLine}
+// thisItem returns the item at the current input point with the specified type
+// and advances the input.
+func (l *lexer) thisItem(t itemType) item {
+	i := item{t, l.start, l.input[l.start:l.pos], l.startLine}
 	l.start = l.pos
 	l.startLine = l.line
+	return i
+}
+
+// emit passes the trailing text as an item back to the parser.
+func (l *lexer) emit(t itemType) stateFn {
+	return l.emitItem(l.thisItem(t))
+}
+
+// emitItem passes the specified item to the parser.
+func (l *lexer) emitItem(i item) stateFn {
+	l.item = i
+	return nil
 }
 
 // ignore skips over the pending input before this point.
+// It tracks newlines in the ignored text, so use it only
+// for text that is skipped without calling l.next.
 func (l *lexer) ignore() {
 	l.line += strings.Count(l.input[l.start:l.pos], "\n")
 	l.start = l.pos
@@ -191,25 +214,31 @@ func (l *lexer) acceptRun(valid string) {
 // errorf returns an error token and terminates the scan by passing
 // back a nil pointer that will be the next state, terminating l.nextItem.
 func (l *lexer) errorf(format string, args ...any) stateFn {
-	l.items <- item{itemError, l.start, fmt.Sprintf(format, args...), l.startLine}
+	l.item = item{itemError, l.start, fmt.Sprintf(format, args...), l.startLine}
+	l.start = 0
+	l.pos = 0
+	l.input = l.input[:0]
 	return nil
 }
 
 // nextItem returns the next item from the input.
 // Called by the parser, not in the lexing goroutine.
 func (l *lexer) nextItem() item {
-	return <-l.items
-}
-
-// drain drains the output so the lexing goroutine will exit.
-// Called by the parser, not in the lexing goroutine.
-func (l *lexer) drain() {
-	for range l.items {
+	l.item = item{itemEOF, l.pos, "EOF", l.startLine}
+	state := lexText
+	if l.insideAction {
+		state = lexInsideAction
+	}
+	for {
+		state = state(l)
+		if state == nil {
+			return l.item
+		}
 	}
 }
 
 // lex creates a new scanner for the input string.
-func lex(name, input, left, right string, emitComment bool) *lexer {
+func lex(name, input, left, right string) *lexer {
 	if left == "" {
 		left = leftDelim
 	}
@@ -217,27 +246,17 @@ func lex(name, input, left, right string, emitComment bool) *lexer {
 		right = rightDelim
 	}
 	l := &lexer{
-		name:        name,
-		input:       input,
-		leftDelim:   left,
-		rightDelim:  right,
-		emitComment: emitComment,
-		items:       make(chan item),
-		line:        1,
-		startLine:   1,
+		name:         name,
+		input:        input,
+		leftDelim:    left,
+		rightDelim:   right,
+		line:         1,
+		startLine:    1,
+		insideAction: false,
 	}
-	go l.run()
 	return l
 }
 
-// run runs the state machine for the lexer.
-func (l *lexer) run() {
-	for state := lexText; state != nil; {
-		state = state(l)
-	}
-	close(l.items)
-}
-
 // state functions
 
 const (
@@ -249,31 +268,33 @@ const (
 
 // lexText scans until an opening action delimiter, "{{".
 func lexText(l *lexer) stateFn {
-	l.width = 0
 	if x := strings.Index(l.input[l.pos:], l.leftDelim); x >= 0 {
-		ldn := Pos(len(l.leftDelim))
-		l.pos += Pos(x)
-		trimLength := Pos(0)
-		if hasLeftTrimMarker(l.input[l.pos+ldn:]) {
-			trimLength = rightTrimLength(l.input[l.start:l.pos])
-		}
-		l.pos -= trimLength
-		if l.pos > l.start {
+		if x > 0 {
+			l.pos += Pos(x)
+			// Do we trim any trailing space?
+			trimLength := Pos(0)
+			delimEnd := l.pos + Pos(len(l.leftDelim))
+			if hasLeftTrimMarker(l.input[delimEnd:]) {
+				trimLength = rightTrimLength(l.input[l.start:l.pos])
+			}
+			l.pos -= trimLength
 			l.line += strings.Count(l.input[l.start:l.pos], "\n")
-			l.emit(itemText)
+			i := l.thisItem(itemText)
+			l.pos += trimLength
+			l.ignore()
+			if len(i.val) > 0 {
+				return l.emitItem(i)
+			}
 		}
-		l.pos += trimLength
-		l.ignore()
 		return lexLeftDelim
 	}
 	l.pos = Pos(len(l.input))
 	// Correctly reached EOF.
 	if l.pos > l.start {
 		l.line += strings.Count(l.input[l.start:l.pos], "\n")
-		l.emit(itemText)
+		return l.emit(itemText)
 	}
-	l.emit(itemEOF)
-	return nil
+	return l.emit(itemEOF)
 }
 
 // rightTrimLength returns the length of the spaces at the end of the string.
@@ -298,6 +319,7 @@ func leftTrimLength(s string) Pos {
 }
 
 // lexLeftDelim scans the left delimiter, which is known to be present, possibly with a trim marker.
+// (The text to be trimmed has already been emitted.)
 func lexLeftDelim(l *lexer) stateFn {
 	l.pos += Pos(len(l.leftDelim))
 	trimSpace := hasLeftTrimMarker(l.input[l.pos:])
@@ -310,28 +332,27 @@ func lexLeftDelim(l *lexer) stateFn {
 		l.ignore()
 		return lexComment
 	}
-	l.emit(itemLeftDelim)
+	i := l.thisItem(itemLeftDelim)
+	l.insideAction = true
 	l.pos += afterMarker
 	l.ignore()
 	l.parenDepth = 0
-	return lexInsideAction
+	return l.emitItem(i)
 }
 
 // lexComment scans a comment. The left comment marker is known to be present.
 func lexComment(l *lexer) stateFn {
 	l.pos += Pos(len(leftComment))
-	i := strings.Index(l.input[l.pos:], rightComment)
-	if i < 0 {
+	x := strings.Index(l.input[l.pos:], rightComment)
+	if x < 0 {
 		return l.errorf("unclosed comment")
 	}
-	l.pos += Pos(i + len(rightComment))
+	l.pos += Pos(x + len(rightComment))
 	delim, trimSpace := l.atRightDelim()
 	if !delim {
 		return l.errorf("comment ends before closing delimiter")
 	}
-	if l.emitComment {
-		l.emit(itemComment)
-	}
+	i := l.thisItem(itemComment)
 	if trimSpace {
 		l.pos += trimMarkerLen
 	}
@@ -340,23 +361,27 @@ func lexComment(l *lexer) stateFn {
 		l.pos += leftTrimLength(l.input[l.pos:])
 	}
 	l.ignore()
+	if l.options.emitComment {
+		return l.emitItem(i)
+	}
 	return lexText
 }
 
 // lexRightDelim scans the right delimiter, which is known to be present, possibly with a trim marker.
 func lexRightDelim(l *lexer) stateFn {
-	trimSpace := hasRightTrimMarker(l.input[l.pos:])
+	_, trimSpace := l.atRightDelim()
 	if trimSpace {
 		l.pos += trimMarkerLen
 		l.ignore()
 	}
 	l.pos += Pos(len(l.rightDelim))
-	l.emit(itemRightDelim)
+	i := l.thisItem(itemRightDelim)
 	if trimSpace {
 		l.pos += leftTrimLength(l.input[l.pos:])
 		l.ignore()
 	}
-	return lexText
+	l.insideAction = false
+	return l.emitItem(i)
 }
 
 // lexInsideAction scans the elements inside action delimiters.
@@ -378,14 +403,14 @@ func lexInsideAction(l *lexer) stateFn {
 		l.backup() // Put space back in case we have " -}}".
 		return lexSpace
 	case r == '=':
-		l.emit(itemAssign)
+		return l.emit(itemAssign)
 	case r == ':':
 		if l.next() != '=' {
 			return l.errorf("expected :=")
 		}
-		l.emit(itemDeclare)
+		return l.emit(itemDeclare)
 	case r == '|':
-		l.emit(itemPipe)
+		return l.emit(itemPipe)
 	case r == '"':
 		return lexQuote
 	case r == '`':
@@ -410,20 +435,19 @@ func lexInsideAction(l *lexer) stateFn {
 		l.backup()
 		return lexIdentifier
 	case r == '(':
-		l.emit(itemLeftParen)
 		l.parenDepth++
+		return l.emit(itemLeftParen)
 	case r == ')':
-		l.emit(itemRightParen)
 		l.parenDepth--
 		if l.parenDepth < 0 {
-			return l.errorf("unexpected right paren %#U", r)
+			return l.errorf("unexpected right paren")
 		}
+		return l.emit(itemRightParen)
 	case r <= unicode.MaxASCII && unicode.IsPrint(r):
-		l.emit(itemChar)
+		return l.emit(itemChar)
 	default:
 		return l.errorf("unrecognized character in action: %#U", r)
 	}
-	return lexInsideAction
 }
 
 // lexSpace scans a run of space characters.
@@ -448,13 +472,11 @@ func lexSpace(l *lexer) stateFn {
 			return lexRightDelim // On the delim, so go right to that.
 		}
 	}
-	l.emit(itemSpace)
-	return lexInsideAction
+	return l.emit(itemSpace)
 }
 
 // lexIdentifier scans an alphanumeric.
 func lexIdentifier(l *lexer) stateFn {
-Loop:
 	for {
 		switch r := l.next(); {
 		case isAlphaNumeric(r):
@@ -468,22 +490,19 @@ Loop:
 			switch {
 			case key[word] > itemKeyword:
 				item := key[word]
-				if item == itemBreak && !l.breakOK || item == itemContinue && !l.continueOK {
-					l.emit(itemIdentifier)
-				} else {
-					l.emit(item)
+				if item == itemBreak && !l.options.breakOK || item == itemContinue && !l.options.continueOK {
+					return l.emit(itemIdentifier)
 				}
+				return l.emit(item)
 			case word[0] == '.':
-				l.emit(itemField)
+				return l.emit(itemField)
 			case word == "true", word == "false":
-				l.emit(itemBool)
+				return l.emit(itemBool)
 			default:
-				l.emit(itemIdentifier)
+				return l.emit(itemIdentifier)
 			}
-			break Loop
 		}
 	}
-	return lexInsideAction
 }
 
 // lexField scans a field: .Alphanumeric.
@@ -496,8 +515,7 @@ func lexField(l *lexer) stateFn {
 // The $ has been scanned.
 func lexVariable(l *lexer) stateFn {
 	if l.atTerminator() { // Nothing interesting follows -> "$".
-		l.emit(itemVariable)
-		return lexInsideAction
+		return l.emit(itemVariable)
 	}
 	return lexFieldOrVariable(l, itemVariable)
 }
@@ -507,11 +525,9 @@ func lexVariable(l *lexer) stateFn {
 func lexFieldOrVariable(l *lexer, typ itemType) stateFn {
 	if l.atTerminator() { // Nothing interesting follows -> "." or "$".
 		if typ == itemVariable {
-			l.emit(itemVariable)
-		} else {
-			l.emit(itemDot)
+			return l.emit(itemVariable)
 		}
-		return lexInsideAction
+		return l.emit(itemDot)
 	}
 	var r rune
 	for {
@@ -524,8 +540,7 @@ func lexFieldOrVariable(l *lexer, typ itemType) stateFn {
 	if !l.atTerminator() {
 		return l.errorf("bad character %#U", r)
 	}
-	l.emit(typ)
-	return lexInsideAction
+	return l.emit(typ)
 }
 
 // atTerminator reports whether the input is at valid termination character to
@@ -541,13 +556,7 @@ func (l *lexer) atTerminator() bool {
 	case eof, '.', ',', '|', ':', ')', '(':
 		return true
 	}
-	// Does r start the delimiter? This can be ambiguous (with delim=="//", $x/2 will
-	// succeed but should fail) but only in extremely rare cases caused by willfully
-	// bad choice of delimiter.
-	if rd, _ := utf8.DecodeRuneInString(l.rightDelim); rd == r {
-		return true
-	}
-	return false
+	return strings.HasPrefix(l.input[l.pos:], l.rightDelim)
 }
 
 // lexChar scans a character constant. The initial quote is already
@@ -567,8 +576,7 @@ Loop:
 			break Loop
 		}
 	}
-	l.emit(itemCharConstant)
-	return lexInsideAction
+	return l.emit(itemCharConstant)
 }
 
 // lexNumber scans a number: decimal, octal, hex, float, or imaginary. This
@@ -584,11 +592,9 @@ func lexNumber(l *lexer) stateFn {
 		if !l.scanNumber() || l.input[l.pos-1] != 'i' {
 			return l.errorf("bad number syntax: %q", l.input[l.start:l.pos])
 		}
-		l.emit(itemComplex)
-	} else {
-		l.emit(itemNumber)
+		return l.emit(itemComplex)
 	}
-	return lexInsideAction
+	return l.emit(itemNumber)
 }
 
 func (l *lexer) scanNumber() bool {
@@ -644,8 +650,7 @@ Loop:
 			break Loop
 		}
 	}
-	l.emit(itemString)
-	return lexInsideAction
+	return l.emit(itemString)
 }
 
 // lexRawQuote scans a raw quoted string.
@@ -659,8 +664,7 @@ Loop:
 			break Loop
 		}
 	}
-	l.emit(itemRawString)
-	return lexInsideAction
+	return l.emit(itemRawString)
 }
 
 // isSpace reports whether r is a space character.

tpl/internal/go_templates/texttemplate/parse/lex_test.go

@@ -362,8 +362,7 @@ var lexTests = []lexTest{
 	{"extra right paren", "{{3)}}", []item{
 		tLeft,
 		mkItem(itemNumber, "3"),
-		tRpar,
-		mkItem(itemError, `unexpected right paren U+0029 ')'`),
+		mkItem(itemError, "unexpected right paren"),
 	}},
 
 	// Fixed bugs
@@ -397,7 +396,12 @@ var lexTests = []lexTest{
 
 // collect gathers the emitted items into a slice.
 func collect(t *lexTest, left, right string) (items []item) {
-	l := lex(t.name, t.input, left, right, true)
+	l := lex(t.name, t.input, left, right)
+	l.options = lexOptions{
+		emitComment: true,
+		breakOK:     true,
+		continueOK:  true,
+	}
 	for {
 		item := l.nextItem()
 		items = append(items, item)
@@ -434,7 +438,9 @@ func TestLex(t *testing.T) {
 		items := collect(&test, "", "")
 		if !equal(items, test.items, false) {
 			t.Errorf("%s: got\n\t%+v\nexpected\n\t%v", test.name, items, test.items)
+			return // TODO
 		}
+		t.Log(test.name, "OK")
 	}
 }
 
@@ -472,6 +478,39 @@ func TestDelims(t *testing.T) {
 	}
 }
 
+func TestDelimsAlphaNumeric(t *testing.T) {
+	test := lexTest{"right delimiter with alphanumeric start", "{{hub .host hub}}", []item{
+		mkItem(itemLeftDelim, "{{hub"),
+		mkItem(itemSpace, " "),
+		mkItem(itemField, ".host"),
+		mkItem(itemSpace, " "),
+		mkItem(itemRightDelim, "hub}}"),
+		tEOF,
+	}}
+	items := collect(&test, "{{hub", "hub}}")
+
+	if !equal(items, test.items, false) {
+		t.Errorf("%s: got\n\t%v\nexpected\n\t%v", test.name, items, test.items)
+	}
+}
+
+func TestDelimsAndMarkers(t *testing.T) {
+	test := lexTest{"delims that look like markers", "{{- .x -}} {{- - .x - -}}", []item{
+		mkItem(itemLeftDelim, "{{- "),
+		mkItem(itemField, ".x"),
+		mkItem(itemRightDelim, " -}}"),
+		mkItem(itemLeftDelim, "{{- "),
+		mkItem(itemField, ".x"),
+		mkItem(itemRightDelim, " -}}"),
+		tEOF,
+	}}
+	items := collect(&test, "{{- ", " -}}")
+
+	if !equal(items, test.items, false) {
+		t.Errorf("%s: got\n\t%v\nexpected\n\t%v", test.name, items, test.items)
+	}
+}
+
 var lexPosTests = []lexTest{
 	{"empty", "", []item{{itemEOF, 0, "", 1}}},
 	{"punctuation", "{{,@%#}}", []item{
@@ -533,22 +572,6 @@ func TestPos(t *testing.T) {
 	}
 }
 
-// Test that an error shuts down the lexing goroutine.
-func TestShutdown(t *testing.T) {
-	// We need to duplicate template.Parse here to hold on to the lexer.
-	const text = "erroneous{{define}}{{else}}1234"
-	lexer := lex("foo", text, "{{", "}}", false)
-	_, err := New("root").parseLexer(lexer)
-	if err == nil {
-		t.Fatalf("expected error")
-	}
-	// The error should have drained the input. Therefore, the lexer should be shut down.
-	token, ok := <-lexer.items
-	if ok {
-		t.Fatalf("input was not drained; got %v", token)
-	}
-}
-
 // parseLexer is a local version of parse that lets us pass in the lexer instead of building it.
 // We expect an error, so the tree set and funcs list are explicitly nil.
 func (t *Tree) parseLexer(lex *lexer) (tree *Tree, err error) {

tpl/internal/go_templates/texttemplate/parse/parse.go

@@ -210,7 +210,6 @@ func (t *Tree) recover(errp *error) {
 			panic(e)
 		}
 		if t != nil {
-			t.lex.drain()
 			t.stopParse()
 		}
 		*errp = e.(error)
@@ -224,8 +223,6 @@ func (t *Tree) startParse(funcs []map[string]any, lex *lexer, treeSet map[string
 	t.vars = []string{"$"}
 	t.funcs = funcs
 	t.treeSet = treeSet
-	lex.breakOK = !t.hasFunction("break")
-	lex.continueOK = !t.hasFunction("continue")
 }
 
 // stopParse terminates parsing.
@@ -243,8 +240,13 @@ func (t *Tree) stopParse() {
 func (t *Tree) Parse(text, leftDelim, rightDelim string, treeSet map[string]*Tree, funcs ...map[string]any) (tree *Tree, err error) {
 	defer t.recover(&err)
 	t.ParseName = t.Name
-	emitComment := t.Mode&ParseComments != 0
-	t.startParse(funcs, lex(t.Name, text, leftDelim, rightDelim, emitComment), treeSet)
+	lexer := lex(t.Name, text, leftDelim, rightDelim)
+	lexer.options = lexOptions{
+		emitComment: t.Mode&ParseComments != 0,
+		breakOK:     !t.hasFunction("break"),
+		continueOK:  !t.hasFunction("continue"),
+	}
+	t.startParse(funcs, lexer, treeSet)
 	t.text = text
 	t.parse()
 	t.add()
@@ -341,7 +343,9 @@ func (t *Tree) parseDefinition() {
 }
 
 // itemList:
+//
 //	textOrAction*
+//
 // Terminates at {{end}} or {{else}}, returned separately.
 func (t *Tree) itemList() (list *ListNode, next Node) {
 	list = t.newList(t.peekNonSpace().pos)
@@ -358,6 +362,7 @@ func (t *Tree) itemList() (list *ListNode, next Node) {
 }
 
 // textOrAction:
+//
 //	text | comment | action
 func (t *Tree) textOrAction() Node {
 	switch token := t.nextNonSpace(); token.typ {
@@ -380,8 +385,10 @@ func (t *Tree) clearActionLine() {
 }
 
 // Action:
+//
 //	control
 //	command ("|" command)*
+//
 // Left delim is past. Now get actions.
 // First word could be a keyword such as range.
 func (t *Tree) action() (n Node) {
@@ -412,7 +419,9 @@ func (t *Tree) action() (n Node) {
 }
 
 // Break:
+//
 //	{{break}}
+//
 // Break keyword is past.
 func (t *Tree) breakControl(pos Pos, line int) Node {
 	if token := t.nextNonSpace(); token.typ != itemRightDelim {
@@ -425,7 +434,9 @@ func (t *Tree) breakControl(pos Pos, line int) Node {
 }
 
 // Continue:
+//
 //	{{continue}}
+//
 // Continue keyword is past.
 func (t *Tree) continueControl(pos Pos, line int) Node {
 	if token := t.nextNonSpace(); token.typ != itemRightDelim {
@@ -438,6 +449,7 @@ func (t *Tree) continueControl(pos Pos, line int) Node {
 }
 
 // Pipeline:
+//
 //	declarations? command ('|' command)*
 func (t *Tree) pipeline(context string, end itemType) (pipe *PipeNode) {
 	token := t.peekNonSpace()
@@ -549,16 +561,20 @@ func (t *Tree) parseControl(allowElseIf bool, context string) (pos Pos, line int
 }
 
 // If:
+//
 //	{{if pipeline}} itemList {{end}}
 //	{{if pipeline}} itemList {{else}} itemList {{end}}
+//
 // If keyword is past.
 func (t *Tree) ifControl() Node {
 	return t.newIf(t.parseControl(true, "if"))
 }
 
 // Range:
+//
 //	{{range pipeline}} itemList {{end}}
 //	{{range pipeline}} itemList {{else}} itemList {{end}}
+//
 // Range keyword is past.
 func (t *Tree) rangeControl() Node {
 	r := t.newRange(t.parseControl(false, "range"))
@@ -566,22 +582,28 @@ func (t *Tree) rangeControl() Node {
 }
 
 // With:
+//
 //	{{with pipeline}} itemList {{end}}
 //	{{with pipeline}} itemList {{else}} itemList {{end}}
+//
 // If keyword is past.
 func (t *Tree) withControl() Node {
 	return t.newWith(t.parseControl(false, "with"))
 }
 
 // End:
+//
 //	{{end}}
+//
 // End keyword is past.
 func (t *Tree) endControl() Node {
 	return t.newEnd(t.expect(itemRightDelim, "end").pos)
 }
 
 // Else:
+//
 //	{{else}}
+//
 // Else keyword is past.
 func (t *Tree) elseControl() Node {
 	// Special case for "else if".
@@ -595,7 +617,9 @@ func (t *Tree) elseControl() Node {
 }
 
 // Block:
+//
 //	{{block stringValue pipeline}}
+//
 // Block keyword is past.
 // The name must be something that can evaluate to a string.
 // The pipeline is mandatory.
@@ -623,7 +647,9 @@ func (t *Tree) blockControl() Node {
 }
 
 // Template:
+//
 //	{{template stringValue pipeline}}
+//
 // Template keyword is past. The name must be something that can evaluate
 // to a string.
 func (t *Tree) templateControl() Node {
@@ -654,7 +680,9 @@ func (t *Tree) parseTemplateName(token item, context string) (name string) {
 }
 
 // command:
+//
 //	operand (space operand)*
+//
 // space-separated arguments up to a pipeline character or right delimiter.
 // we consume the pipe character but leave the right delim to terminate the action.
 func (t *Tree) command() *CommandNode {
@@ -684,7 +712,9 @@ func (t *Tree) command() *CommandNode {
 }
 
 // operand:
+//
 //	term .Field*
+//
 // An operand is a space-separated component of a command,
 // a term possibly followed by field accesses.
 // A nil return means the next item is not an operand.
@@ -718,12 +748,14 @@ func (t *Tree) operand() Node {
 }
 
 // term:
+//
 //	literal (number, string, nil, boolean)
 //	function (identifier)
 //	.
 //	.Field
 //	$
 //	'(' pipeline ')'
+//
 // A term is a simple "expression".
 // A nil return means the next item is not a term.
 func (t *Tree) term() Node {

tpl/internal/go_templates/texttemplate/parse/parse_test.go

@@ -492,7 +492,7 @@ var errorTests = []parseTest{
 		hasError, `unclosed left paren`},
 	{"rparen",
 		"{{.X 1 2 3 ) }}",
-		hasError, `unexpected ")" in command`},
+		hasError, "unexpected right paren"},
 	{"rparen2",
 		"{{(.X 1 2 3",
 		hasError, `unclosed action`},
@@ -600,7 +600,8 @@ func TestBlock(t *testing.T) {
 }
 
 func TestLineNum(t *testing.T) {
-	const count = 100
+	// const count = 100
+	const count = 3
 	text := strings.Repeat("{{printf 1234}}\n", count)
 	tree, err := New("bench").Parse(text, "", "", make(map[string]*Tree), builtins)
 	if err != nil {
@@ -614,11 +615,11 @@ func TestLineNum(t *testing.T) {
 		// Action first.
 		action := nodes[i].(*ActionNode)
 		if action.Line != line {
-			t.Fatalf("line %d: action is line %d", line, action.Line)
+			t.Errorf("line %d: action is line %d", line, action.Line)
 		}
 		pipe := action.Pipe
 		if pipe.Line != line {
-			t.Fatalf("line %d: pipe is line %d", line, pipe.Line)
+			t.Errorf("line %d: pipe is line %d", line, pipe.Line)
 		}
 	}
 }