generate: Add comments to lexer

generate/lex.go

@@ -15,6 +15,7 @@ const (
 	TokenRBrace
 	TokenLBracket
 	TokenRBracket
+	TokenComment
 )
 
 var tokenNames = map[parse.TokenKind] string {
@@ -26,6 +27,7 @@ var tokenNames = map[parse.TokenKind] string {
 	TokenRBrace:   "RBrace",
 	TokenLBracket: "LBracket",
 	TokenRBracket: "RBracket",
+	TokenComment:  "Comment",
 }
 
 func Lex(fileName string, reader io.Reader) (parse.Lexer, error) {
@@ -81,6 +83,18 @@ func (this *lexer) nextInternal() (token parse.Token, err error) {
 		}
 	}
 
+	unexpected := func() error {
+		if unicode.IsPrint(this.rune) {
+			return parse.Errorf (
+				this.pos(), "unexpected rune '%c'",
+				this.rune)
+		} else {
+			return parse.Errorf (
+				this.pos(), "unexpected rune %U",
+				this.rune)
+		}
+	}
+
 	defer func () {
 		newPos := this.pos()
 		newPos.End -- // TODO figure out why tf we have to do this
@@ -133,14 +147,21 @@ func (this *lexer) nextInternal() (token parse.Token, err error) {
 		token.Kind = TokenRBracket
 		appendRune()
 		if this.eof { err = nil; return }
-	case unicode.IsPrint(this.rune):
-		err = parse.Errorf (
-			this.pos(), "unexpected rune '%c'",
-			this.rune)
+	// Comment
+	case this.rune == '/':
+		token.Kind = TokenComment
+		appendRune()
+		if this.eof { return }
+		if this.rune != '/' {
+			err = unexpected()
+			return
+		}
+		for this.rune != '\n' {
+			appendRune()
+			if this.eof { err = nil; return }
+		}
 	default:
-		err = parse.Errorf (
-			this.pos(), "unexpected rune %U",
-			this.rune)
+		err = unexpected()
 	}
 
 	return