cleanup and reorganization

src/irc/parse.go

@@ -1,13 +1,11 @@
 package irc
 
 import (
-	"fmt"
-	"regexp"
-	"strconv"
+	"errors"
 	"strings"
 )
 
-var commands = map[string]func([]string) Message{
+var commands = map[string]func([]string) (Message, error){
 	"JOIN":    NewJoinMessage,
 	"MODE":    NewModeMessage,
 	"NICK":    NewNickMessage,
@@ -20,169 +18,43 @@ var commands = map[string]func([]string) Message{
 	"USER":    NewUserMessage,
 }
 
-func ParseMessage(line string) Message {
+var (
+	ErrParseMessage = errors.New("failed to parse message")
+)
+
+func ParseMessage(line string) (msg Message, err error) {
 	command, args := parseLine(line)
 	constructor, ok := commands[command]
-	var msg Message
-	if ok {
-		msg = constructor(args)
-	}
-	if msg == nil {
+	if !ok {
 		msg = &UnknownMessage{command}
+		return
 	}
-	return msg
+	msg, err = constructor(args)
+	return
 }
 
-func parseArg(line string) (string, string) {
+func parseArg(line string) (arg string, rest string) {
 	if line == "" {
-		return "", ""
+		return
 	}
 
 	if strings.HasPrefix(line, ":") {
-		return line[1:], ""
+		arg = line[1:]
+	} else {
+		parts := strings.SplitN(line, " ", 2)
+		arg = parts[0]
+		if len(parts) > 1 {
+			rest = parts[1]
+		}
 	}
-
-	parts := strings.SplitN(line, " ", 2)
-	arg := parts[0]
-	rest := ""
-	if len(parts) > 1 {
-		rest = parts[1]
-	}
-	return arg, rest
+	return
 }
 
-func parseLine(line string) (string, []string) {
-	args := make([]string, 0)
+func parseLine(line string) (command string, args []string) {
+	args = make([]string, 0)
 	for arg, rest := parseArg(line); arg != ""; arg, rest = parseArg(rest) {
 		args = append(args, arg)
 	}
-	return args[0], args[1:]
-}
-
-// []string => Message constructors
-
-func NewNickMessage(args []string) Message {
-	if len(args) != 1 {
-		return nil
-	}
-	return &NickMessage{args[0]}
-}
-
-func NewPingMessage(args []string) Message {
-	if len(args) < 1 {
-		return nil
-	}
-	message := &PingMessage{server: args[0]}
-	if len(args) > 1 {
-		message.server2 = args[1]
-	}
-	return message
-}
-
-func NewPongMessage(args []string) Message {
-	if len(args) < 1 {
-		return nil
-	}
-	message := &PongMessage{server1: args[0]}
-	if len(args) > 1 {
-		message.server2 = args[1]
-	}
-	return message
-}
-
-func NewQuitMessage(args []string) Message {
-	msg := QuitMessage{}
-	if len(args) > 0 {
-		msg.message = args[0]
-	}
-	return &msg
-}
-
-func NewUserMessage(args []string) Message {
-	if len(args) != 4 {
-		return nil
-	}
-	msg := new(UserMessage)
-	msg.user = args[0]
-	mode, err := strconv.ParseUint(args[1], 10, 8)
-	if err == nil {
-		msg.mode = uint8(mode)
-	}
-	msg.unused = args[2]
-	msg.realname = args[3]
-	return msg
-}
-
-var MODE_RE = regexp.MustCompile("^[-+][a-zA-Z]+$")
-
-func NewModeMessage(args []string) Message {
-	if len(args) < 1 {
-		return nil
-	}
-	msg := new(ModeMessage)
-	msg.nickname = args[0]
-	for _, arg := range args[1:] {
-		if !MODE_RE.MatchString(arg) {
-			// TODO invalid args
-			return nil
-		}
-		prefix := arg[0]
-		for _, c := range arg[1:] {
-			mode := fmt.Sprintf("%c%c", prefix, c)
-			msg.modes = append(msg.modes, mode)
-		}
-	}
-	return msg
-}
-
-func NewJoinMessage(args []string) Message {
-	msg := new(JoinMessage)
-
-	if len(args) > 0 {
-		if args[0] == "0" {
-			msg.zero = true
-		} else {
-			msg.channels = strings.Split(args[0], ",")
-		}
-
-		if len(args) > 1 {
-			msg.keys = strings.Split(args[1], ",")
-		}
-	}
-
-	return msg
-}
-
-func NewPartMessage(args []string) Message {
-	if len(args) < 1 {
-		return nil
-	}
-	msg := new(PartMessage)
-	msg.channels = strings.Split(args[0], ",")
-
-	if len(args) > 1 {
-		msg.message = args[1]
-	}
-
-	return msg
-}
-
-func NewPrivMsgMessage(args []string) Message {
-	if len(args) < 2 {
-		return nil
-	}
-
-	return &PrivMsgMessage{target: args[0], message: args[1]}
-}
-
-func NewTopicMessage(args []string) Message {
-	if len(args) < 1 {
-		return nil
-	}
-
-	message := &TopicMessage{channel: args[0]}
-	if len(args) > 1 {
-		message.topic = args[1]
-	}
-	return message
+	command, args = args[0], args[1:]
+	return
 }