refactored map field

Change-Id: Iaf399df54da3f0ea9e54926f0b6e3ee8a7249c9a

field.go

@@ -1,27 +1,31 @@
 package proto3
 
-import (
-	"fmt"
-	"strconv"
-)
+import "strconv"
 
-// Field is a message field.
+// Field is an abstract message field.
 type Field struct {
 	Name     string
 	Type     string
-	Repeated bool
 	Sequence int
 	Options  []*Option
 }
 
+// NormalField
+type NormalField struct {
+	*Field
+	Repeated bool
+}
+
+func newNormalField() *NormalField { return &NormalField{Field: new(Field)} }
+
 // Accept dispatches the call to the visitor.
-func (f *Field) Accept(v Visitor) {
-	v.VisitField(f)
+func (f *NormalField) Accept(v Visitor) {
+	v.VisitNormalField(f)
 }
 
 // parse expects:
 // [ "repeated" ] type fieldName "=" fieldNumber [ "[" fieldOptions "]" ] ";"
-func (f *Field) parse(p *Parser) error {
+func (f *NormalField) parse(p *Parser) error {
 	for {
 		tok, lit := p.scanIgnoreWhitespace()
 		switch tok {
@@ -30,7 +34,7 @@ func (f *Field) parse(p *Parser) error {
 			return f.parse(p)
 		case tIDENT:
 			f.Type = lit
-			return parseFieldAfterType(f, p)
+			return parseFieldAfterType(f.Field, p)
 		default:
 			goto done
 		}
@@ -39,18 +43,6 @@ done:
 	return nil
 }
 
-// parseMapField continues after scanning "map"
-func parseMapField(f *Field, p *Parser) error {
-	tok, lit := p.scanIgnoreWhitespace()
-	if tLESS != tok {
-		return p.unexpected(lit, "<")
-	}
-	// TODO proper parsing key-value type
-	kvtypes := p.s.scanUntil('>')
-	f.Type = fmt.Sprintf("map<%s>", kvtypes)
-	return parseFieldAfterType(f, p)
-}
-
 // parseFieldAfterType expects:
 // fieldName "=" fieldNumber [ "[" fieldOptions "]" ] ";
 func parseFieldAfterType(f *Field, p *Parser) error {
@@ -98,13 +90,12 @@ func parseFieldAfterType(f *Field, p *Parser) error {
 
 // MapField represents a map entry in a message.
 type MapField struct {
-	Name     string
-	KeyType  string
-	Type     string
-	Sequence int
-	Options  []*Option
+	*Field
+	KeyType string
 }
 
+func newMapField() *MapField { return &MapField{Field: new(Field)} }
+
 // Accept dispatches the call to the visitor.
 func (f *MapField) Accept(v Visitor) {
 	v.VisitMapField(f)
@@ -115,5 +106,27 @@ func (f *MapField) Accept(v Visitor) {
 // keyType = "int32" | "int64" | "uint32" | "uint64" | "sint32" | "sint64" |
 //           "fixed32" | "fixed64" | "sfixed32" | "sfixed64" | "bool" | "string"
 func (f *MapField) parse(p *Parser) error {
-	return nil
+	tok, lit := p.scanIgnoreWhitespace()
+	if tLESS != tok {
+		return p.unexpected(lit, "<")
+	}
+	tok, lit = p.scanIgnoreWhitespace()
+	if tIDENT != tok {
+		return p.unexpected(lit, "identifier")
+	}
+	f.KeyType = lit
+	tok, lit = p.scanIgnoreWhitespace()
+	if tCOMMA != tok {
+		return p.unexpected(lit, ",")
+	}
+	tok, lit = p.scanIgnoreWhitespace()
+	if tIDENT != tok {
+		return p.unexpected(lit, "identifier")
+	}
+	f.Type = lit
+	tok, lit = p.scanIgnoreWhitespace()
+	if tGREATER != tok {
+		return p.unexpected(lit, ">")
+	}
+	return parseFieldAfterType(f.Field, p)
 }

field_test.go

@@ -5,7 +5,7 @@ import "testing"
 func TestField(t *testing.T) {
 	proto := `repeated foo.bar lots = 1 [option1=a, option2=b, option3="happy"];`
 	p := newParserOn(proto)
-	f := new(Field)
+	f := newNormalField()
 	err := f.parse(p)
 	if err != nil {
 		t.Fatal(err)
@@ -42,7 +42,7 @@ func TestField(t *testing.T) {
 func TestFieldSimple(t *testing.T) {
 	proto := `string optional_string_piece = 24 [ctype=STRING_PIECE];`
 	p := newParserOn(proto)
-	f := new(Field)
+	f := newNormalField()
 	err := f.parse(p)
 	if err != nil {
 		t.Fatal(err)
@@ -72,9 +72,19 @@ func TestFieldSyntaxErrors(t *testing.T) {
 		`repeatet foo.bar lots = 1;`,
 		`string lots === 1;`,
 	} {
-		f := new(Field)
+		f := newNormalField()
 		if f.parse(newParserOn(each)) == nil {
 			t.Errorf("uncaught syntax error in test case %d, %#v", i, f)
 		}
 	}
 }
+
+func TestMapField(t *testing.T) {
+	proto := ` <string, Project> projects = 3;`
+	p := newParserOn(proto)
+	f := newMapField()
+	err := f.parse(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+}

message.go

@@ -51,8 +51,8 @@ func (m *Message) parse(p *Parser) error {
 			}
 			m.Elements = append(m.Elements, o)
 		case tMAP:
-			f := new(Field)
-			if err := parseMapField(f, p); err != nil {
+			f := newMapField()
+			if err := f.parse(p); err != nil {
 				return err
 			}
 			m.Elements = append(m.Elements, f)
@@ -69,7 +69,7 @@ func (m *Message) parse(p *Parser) error {
 		default:
 			// tFIELD
 			p.unscan()
-			f := new(Field)
+			f := newNormalField()
 			if err := f.parse(p); err != nil {
 				return err
 			}

message_test.go

@@ -4,15 +4,15 @@ import "testing"
 
 func TestMessage(t *testing.T) {
 	proto := `
-		message Out {
+		message   Out   {
 		// identifier
 		string   id  = 1;
 		// size
 		int64   size = 2;
 		
-		oneof   foo {
-			string  name = 4;
-			SubMessage  sub_message = 9;
+		oneof foo {
+			string     name        = 4;
+			SubMessage sub_message = 9;
 		}
 		message  Inner {   // Level 2
    			int64  ival = 1;

scanner.go

@@ -67,6 +67,8 @@ func (s *scanner) scan() (tok token, lit string) {
 		return tCOMMA, string(ch)
 	case '.':
 		return tDOT, string(ch)
+	case '>':
+		return tGREATER, string(ch)
 	}
 	return tILLEGAL, string(ch)
 }

token.go

@@ -24,6 +24,7 @@ const (
 	tRIGHTSQUARE // ]
 	tCOMMENT     // /
 	tLESS        // <
+	tGREATER     // >
 	tCOMMA       // ,
 	tDOT         // .
 

visitor.go

@@ -8,7 +8,7 @@ type Visitor interface {
 	VisitPackage(p *Package)
 	VisitOption(o *Option)
 	VisitImport(i *Import)
-	VisitField(i *Field)
+	VisitNormalField(i *NormalField)
 	VisitEnumField(i *EnumField)
 	VisitEnum(e *Enum)
 	VisitComment(e *Comment)