exp/template: change the name from 'metacharacter' to 'delimiter',

because that's what they are.
No semantic change.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/4675060

src/pkg/exp/template/lex.go

@@ -41,11 +41,11 @@ const (
 	itemEOF
 	itemField      // alphanumeric identifier, starting with '.', possibly chained ('.x.y')
 	itemIdentifier // alphanumeric identifier
-	itemLeftMeta   // left meta-string
+	itemLeftDelim  // left action delimiter
 	itemNumber     // simple number, including imaginary
 	itemPipe       // pipe symbol
 	itemRawString  // raw quoted string (includes quotes)
-	itemRightMeta  // right meta-string
+	itemRightDelim // right action delimiter
 	itemString     // quoted string (includes quotes)
 	itemText       // plain text
 	// Keywords appear after all the rest.
@@ -68,11 +68,11 @@ var itemName = map[itemType]string{
 	itemEOF:        "EOF",
 	itemField:      "field",
 	itemIdentifier: "identifier",
-	itemLeftMeta:   "left meta",
+	itemLeftDelim:  "left delim",
 	itemNumber:     "number",
 	itemPipe:       "pipe",
 	itemRawString:  "raw string",
-	itemRightMeta:  "rightMeta",
+	itemRightDelim: "right delim",
 	itemString:     "string",
 	// keywords
 	itemDot:      ".",
@@ -210,20 +210,20 @@ func lex(name, input string) *lexer {
 // state functions
 
 const (
-	leftMeta     = "{{"
+	leftDelim    = "{{"
-	rightMeta    = "}}"
+	rightDelim   = "}}"
 	leftComment  = "{{/*"
 	rightComment = "*/}}"
 )
 
-// lexText scans until a metacharacter
+// lexText scans until an opening action delimiter, "{{".
 func lexText(l *lexer) stateFn {
 	for {
-		if strings.HasPrefix(l.input[l.pos:], leftMeta) {
+		if strings.HasPrefix(l.input[l.pos:], leftDelim) {
 			if l.pos > l.start {
 				l.emit(itemText)
 			}
-			return lexLeftMeta
+			return lexLeftDelim
 		}
 		if l.next() == eof {
 			break
@@ -237,13 +237,13 @@ func lexText(l *lexer) stateFn {
 	return nil
 }
 
-// leftMeta scans the left "metacharacter", which is known to be present.
+// lexLeftDelim scans the left delimiter, which is known to be present.
-func lexLeftMeta(l *lexer) stateFn {
+func lexLeftDelim(l *lexer) stateFn {
 	if strings.HasPrefix(l.input[l.pos:], leftComment) {
 		return lexComment
 	}
-	l.pos += len(leftMeta)
+	l.pos += len(leftDelim)
-	l.emit(itemLeftMeta)
+	l.emit(itemLeftDelim)
 	return lexInsideAction
 }
 
@@ -258,21 +258,21 @@ func lexComment(l *lexer) stateFn {
 	return lexText
 }
 
-// rightMeta scans the right "metacharacter", which is known to be present.
+// lexRightDelim scans the right delimiter, which is known to be present.
-func lexRightMeta(l *lexer) stateFn {
+func lexRightDelim(l *lexer) stateFn {
-	l.pos += len(rightMeta)
+	l.pos += len(rightDelim)
-	l.emit(itemRightMeta)
+	l.emit(itemRightDelim)
 	return lexText
 }
 
-// lexInsideAction scans the elements inside "metacharacters".
+// lexInsideAction scans the elements inside action delimiters.
 func lexInsideAction(l *lexer) stateFn {
 	// Either number, quoted string, or identifier.
 	// Spaces separate and are ignored.
 	// Pipe symbols separate and are emitted.
 	for {
-		if strings.HasPrefix(l.input[l.pos:], rightMeta) {
+		if strings.HasPrefix(l.input[l.pos:], rightDelim) {
-			return lexRightMeta
+			return lexRightDelim
 		}
 		switch r := l.next(); {
 		case r == eof || r == '\n':

src/pkg/exp/template/lex_test.go

@@ -17,8 +17,8 @@ type lexTest struct {
 
 var (
 	tEOF      = item{itemEOF, ""}
-	tLeft     = item{itemLeftMeta, "{{"}
+	tLeft     = item{itemLeftDelim, "{{"}
-	tRight    = item{itemRightMeta, "}}"}
+	tRight    = item{itemRightDelim, "}}"}
 	tRange    = item{itemRange, "range"}
 	tPipe     = item{itemPipe, "|"}
 	tFor      = item{itemIdentifier, "for"}

src/pkg/exp/template/parse.go

@@ -122,7 +122,7 @@ func (t *textNode) String() string {
 	return fmt.Sprintf("(text: %q)", t.text)
 }
 
-// actionNode holds an action (something bounded by metacharacters).
+// actionNode holds an action (something bounded by delimiters).
 type actionNode struct {
 	nodeType
 	line     int
@@ -594,7 +594,7 @@ func (t *Template) textOrAction() node {
 	switch token := t.next(); token.typ {
 	case itemText:
 		return newText(token.val)
-	case itemLeftMeta:
+	case itemLeftDelim:
 		return t.action()
 	default:
 		t.unexpected(token, "input")
@@ -605,7 +605,7 @@ func (t *Template) textOrAction() node {
 // Action:
 //	control
 //	command ("|" command)*
-// Left meta is past. Now get actions.
+// Left delim is past. Now get actions.
 // First word could be a keyword such as range.
 func (t *Template) action() (n node) {
 	switch token := t.next(); token.typ {
@@ -632,7 +632,7 @@ func (t *Template) action() (n node) {
 func (t *Template) pipeline(context string) (pipe []*commandNode) {
 	for {
 		switch token := t.next(); token.typ {
-		case itemRightMeta:
+		case itemRightDelim:
 			if len(pipe) == 0 {
 				t.errorf("missing value for %s", context)
 			}
@@ -693,7 +693,7 @@ func (t *Template) withControl() node {
 //	{{end}}
 // End keyword is past.
 func (t *Template) endControl() node {
-	t.expect(itemRightMeta, "end")
+	t.expect(itemRightDelim, "end")
 	return newEnd()
 }
 
@@ -701,7 +701,7 @@ func (t *Template) endControl() node {
 //	{{else}}
 // Else keyword is past.
 func (t *Template) elseControl() node {
-	t.expect(itemRightMeta, "else")
+	t.expect(itemRightDelim, "else")
 	return newElse(t.lex.lineNumber())
 }
 
@@ -735,14 +735,14 @@ func (t *Template) templateControl() node {
 }
 
 // command:
-// space-separated arguments up to a pipeline character or right metacharacter.
+// space-separated arguments up to a pipeline character or right delimiter.
-// we consume the pipe character but leave the right meta to terminate the action.
+// we consume the pipe character but leave the right delim to terminate the action.
 func (t *Template) command() *commandNode {
 	cmd := newCommand()
 Loop:
 	for {
 		switch token := t.next(); token.typ {
-		case itemRightMeta:
+		case itemRightDelim:
 			t.backup()
 			break Loop
 		case itemPipe:

src/pkg/exp/template/parse_test.go

@@ -140,7 +140,7 @@ var parseTests = []parseTest{
 		`[(text: " \t\n")]`},
 	{"text", "some text", noError,
 		`[(text: "some text")]`},
-	{"emptyMeta", "{{}}", hasError,
+	{"emptyAction", "{{}}", hasError,
 		`[(action: [])]`},
 	{"field", "{{.X}}", noError,
 		`[(action: [(command: [F=[X]])])]`},

src/pkg/exp/template/set.go

@@ -93,14 +93,14 @@ func (s *Set) Parse(text string) (err os.Error) {
 		if t.atEOF() {
 			return
 		}
-		t.expect(itemLeftMeta, context)
+		t.expect(itemLeftDelim, context)
 		t.expect(itemDefine, context)
 		name := t.expect(itemString, context)
 		t.name, err = strconv.Unquote(name.val)
 		if err != nil {
 			t.error(err)
 		}
-		t.expect(itemRightMeta, context)
+		t.expect(itemRightDelim, context)
 		end := t.parse(false)
 		if end == nil {
 			t.errorf("unexpected EOF in %s", context)