Allow trailing semicolon (";") for rules

lib/metagrammar.pegjs

@@ -6,7 +6,7 @@ grammar
     }
 
 rule
-  = name:identifier displayName:(literal / "") equals expression:expression {
+  = name:identifier displayName:(literal / "") equals expression:expression semicolon? {
       return {
         type:        "rule",
         name:        name,
@@ -136,17 +136,18 @@ nonBraceCharacters
 nonBraceCharacter
   = [^{}]
 
-equals   = "=" __ { return "="; }
-colon    = ":" __ { return ":"; }
-slash    = "/" __ { return "/"; }
-and      = "&" __ { return "&"; }
-not      = "!" __ { return "!"; }
-question = "?" __ { return "?"; }
-star     = "*" __ { return "*"; }
-plus     = "+" __ { return "+"; }
-lparen   = "(" __ { return "("; }
-rparen   = ")" __ { return ")"; }
-dot      = "." __ { return "."; }
+equals    = "=" __ { return "="; }
+colon     = ":" __ { return ":"; }
+semicolon = ";" __ { return ";"; }
+slash     = "/" __ { return "/"; }
+and       = "&" __ { return "&"; }
+not       = "!" __ { return "!"; }
+question  = "?" __ { return "?"; }
+star      = "*" __ { return "*"; }
+plus      = "+" __ { return "+"; }
+lparen    = "(" __ { return "("; }
+rparen    = ")" __ { return ")"; }
+dot       = "." __ { return "."; }
 
 /*
  * Modelled after ECMA-262, 5th ed., 7.6, but much simplified:

test/compiler-test.js

@@ -240,7 +240,7 @@ test("buildParser reports left recursion", function() {
     'start = start { }',
 
     /* Indirect */
-    'start = stop\nstop = start'
+    'start = stop; stop = start'
   ];
 
   PEG.ArrayUtils.each(grammars, function(grammar) {

test/metagrammar-test.js

@@ -144,11 +144,11 @@ function actionGrammar(action) {
   return oneRuleGrammar(action_(literal("a"), action));
 }
 
-/* Canonical grammar is "a: \"abcd\";\nb: \"efgh\";\nc: \"ijkl\";". */
+/* Canonical grammar is "a: \"abcd\"; b: \"efgh\"; c: \"ijkl\";". */
 test("parses grammar", function() {
   grammarParserParses('a = "abcd"', { a: rule("a", null, literalAbcd) });
   grammarParserParses(
-    'a = "abcd"\nb = "efgh"\nc = "ijkl"',
+    'a = "abcd"; b = "efgh"; c = "ijkl"',
     {
       a: rule("a", null, literalAbcd),
       b: rule("b", null, literalEfgh),
@@ -169,6 +169,10 @@ test("parses rule", function() {
       start: rule("start", "start rule", choiceLiterals)
     }
   );
+  grammarParserParses(
+    'start = "abcd" / "efgh" / "ijkl";',
+    oneRuleGrammar(choiceLiterals)
+  );
 });
 
 /* Canonical expression is "\"abcd\" / \"efgh\" / \"ijkl\"". */