refactoring, better line count, begin with visitor, travis

.travis.yml

@@ -0,0 +1,4 @@
+language: go
+
+go:
+  - 1.x

README.md

@@ -1,5 +1,11 @@
 # proto3
 
-Package for parsing Google Protocol Buffers [.proto files version 3] (https://developers.google.com/protocol-buffers/docs/reference/proto3-spec)
+[![Build Status](https://travis-ci.org/emicklei/proto3.png)](https://travis-ci.org/emicklei/proto3)
+
+Package in Go for parsing Google Protocol Buffers [.proto files version 3] (https://developers.google.com/protocol-buffers/docs/reference/proto3-spec)
+
+### install
+
+    go get -u -v github.com/emicklei/proto
 
 (c) 2017, ernestmicklei.com.  MIT License. Contributions welcome.

cmd/proto3fmt/example1.proto

@@ -0,0 +1,56 @@
+syntax = "proto3";
+
+import "google/protobuf/any.proto";
+import "testdata/test.proto";
+
+package proto3_proto;
+
+message Message {
+  enum Humour {
+    UNKNOWN = 0;
+    PUNS = 1;
+    SLAPSTICK = 2;
+    BILL_BAILEY = 3;
+  }
+
+  string name = 1;
+  Humour hilarity = 2;
+  uint32 height_in_cm = 3;
+  bytes data = 4;
+  int64 result_count = 7;
+  bool true_scotsman = 8;
+  float score = 9;
+
+  repeated uint64 key = 5;
+  repeated int32 short_key = 19;
+  Nested nested = 6;
+  repeated Humour r_funny = 16;
+
+  map<string, Nested> terrain = 10;
+  testdata.SubDefaults proto2_field = 11;
+  map<string, testdata.SubDefaults> proto2_value = 13;
+
+  google.protobuf.Any anything = 14;
+  repeated google.protobuf.Any many_things = 15;
+
+  Message submessage = 17;
+  repeated Message children = 18;
+}
+
+message Nested {
+  string bunny = 1;
+  bool cute = 2;
+}
+
+message MessageWithMap {
+  map<bool, bytes> byte_mapping = 1;
+}
+
+
+message IntMap {
+  map<int32, int32> rtt = 1;
+}
+
+message IntMaps {
+  repeated IntMap maps = 1;
+}

cmd/proto3fmt/main.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"log"
+	"os"
+
+	"github.com/emicklei/proto3"
+)
+
+func main() {
+	p := proto3.NewParser(os.Stdin)
+	def, err := p.Parse()
+	if err != nil {
+		log.Fatalln("proto3fmt failed:", p.Line(), err)
+	}
+	log.Printf("%#v", def)
+}

field.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 )
 
+// Field is a message field.
 type Field struct {
 	Name     string
 	Type     string
@@ -14,8 +15,7 @@ type Field struct {
 	Sequence int
 }
 
-// parseField parsers one field.
-func parseField(f *Field, p *Parser) error {
+func (f *Field) parse(p *Parser) error {
 	for {
 		tok, lit := p.scanIgnoreWhitespace()
 		switch tok {
@@ -36,7 +36,7 @@ func parseField(f *Field, p *Parser) error {
 			f.Messages = append(f.Messages, m)
 		case REPEATED:
 			f.Repeated = true
-			return parseField(f, p)
+			return f.parse(p)
 		default:
 			goto done
 		}

field_test.go

@@ -9,7 +9,7 @@ func TestRepeatedField(t *testing.T) {
 	proto := `repeated string lots = 1;`
 	p := NewParser(strings.NewReader(proto))
 	f := new(Field)
-	err := parseField(f, p)
+	err := f.parse(p)
 	if err != nil {
 		t.Fatal(err)
 	}

import.go

@@ -1,31 +1,28 @@
 package proto3
 
-import (
-	"fmt"
-	"strings"
-)
+import "fmt"
 
+// Import holds a filename to another .proto definition.
 type Import struct {
 	Line     int
 	Filename string
-	Kind     string // weak, public
+	Kind     string // weak, public, <empty>
 }
 
 func (i *Import) parse(p *Parser) error {
 	tok, lit := p.scanIgnoreWhitespace()
-	if tok != IDENT || !strings.Contains("weak public", lit) {
-		return fmt.Errorf("found %q, expected kind (weak|public)", lit)
-	}
 	i.Line = p.s.line
-	i.Kind = lit
-	tok, lit = p.scanIgnoreWhitespace()
-	if tok != QUOTE {
-		return fmt.Errorf("found %q, expected \"", lit)
-	}
-	name := p.s.scanUntil('"')
-	if len(name) == 0 {
-		return fmt.Errorf("unexpected end of quoted string")
+	switch tok {
+	case WEAK:
+		i.Kind = lit
+		return i.parse(p)
+	case PUBLIC:
+		i.Kind = lit
+		return i.parse(p)
+	case QUOTE:
+		i.Filename = p.s.scanUntil('"')
+	default:
+		return fmt.Errorf("found %q, expected weak|public|quoted identifier", lit)
 	}
-	i.Filename = name
 	return nil
 }

message.go

@@ -14,7 +14,7 @@ type Message struct {
 func (m *Message) parse(p *Parser) error {
 	tok, lit := p.scanIgnoreWhitespace()
 	if tok != IDENT {
-		return fmt.Errorf("found %q, expected name", lit)
+		return fmt.Errorf("found %q, expected identifier", lit)
 	}
 	m.Name = lit
 	tok, lit = p.scanIgnoreWhitespace()
@@ -32,7 +32,7 @@ func (m *Message) parse(p *Parser) error {
 		default:
 			p.unscan()
 			f := new(Field)
-			err := parseField(f, p)
+			err := f.parse(p)
 			if err != nil {
 				return err
 			}

option.go

@@ -2,13 +2,19 @@ package proto3
 
 import "fmt"
 
+// Option is a protoc compiler option
 type Option struct {
 	Line    int
 	Name    string
 	String  string
 	Boolean bool
 }
 
+// accept dispatches the call to the visitor.
+func (o *Option) accept(v Visitor) {
+	v.VisitOption(o)
+}
+
 func (o *Option) parse(p *Parser) error {
 	tok, lit := p.scanIgnoreWhitespace()
 	switch tok {

package.go

@@ -1,9 +1,15 @@
 package proto3
 
+// Package specifies the namespace for all proto elements.
 type Package struct {
 	Name string
 }
 
-func (a *Package) parse(p *Parser) error {
+// accept dispatches the call to the visitor.
+func (p *Package) accept(v Visitor) {
+	v.VisitPackage(p)
+}
+
+func (p *Package) parse(pr *Parser) error {
 	return nil
 }

parser.go

@@ -21,7 +21,7 @@ func NewParser(r io.Reader) *Parser {
 // Parse parses a proto definition.
 func (p *Parser) Parse() (*Proto, error) {
 	proto := new(Proto)
-	return proto, parseProto(proto, p)
+	return proto, proto.parse(p)
 }
 
 // scan returns the next token from the underlying scanner.
@@ -61,3 +61,6 @@ func (p *Parser) newComment(lit string) *Comment {
 		Message: lit,
 	}
 }
+
+// Line returns the line number on which the last token was read.
+func (p *Parser) Line() int { return p.s.line }

proto.go

@@ -23,8 +23,8 @@ func (c Comment) IsMultiline() bool {
 	return strings.Contains(c.Message, "\n")
 }
 
-// parseProto parsers a complete .proto definition source.
-func parseProto(proto *Proto, p *Parser) error {
+// parse parsers a complete .proto definition source.
+func (proto *Proto) parse(p *Parser) error {
 	tok, lit := p.scanIgnoreWhitespace()
 	switch tok {
 	case COMMENT:
@@ -49,7 +49,8 @@ func parseProto(proto *Proto, p *Parser) error {
 		proto.Enums = append(proto.Enums, enum)
 	case SERVICE:
 		// TODO
-		service, err := parseService(p)
+		service := new(Service)
+		err := service.parse(p)
 		if err != nil {
 			return err
 		}
@@ -63,5 +64,5 @@ func parseProto(proto *Proto, p *Parser) error {
 	case EOF:
 		return nil
 	}
-	return parseProto(proto, p)
+	return proto.parse(p)
 }