Fraction class prototype and test (not to be committed).

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
diff --git a/runtime/vm/parser.cc b/runtime/vm/parser.cc
index 6c0bd7df21a00ac562e3cb86218b3022b1bb842c..1707067583b8c481ab5ddfeed7aaecd4745d9360 100644
--- a/runtime/vm/parser.cc
+++ b/runtime/vm/parser.cc
@@ -625,6 +625,13 @@ RawInteger* Parser::CurrentIntegerLiteral() const {
 }
 
 
+RawFraction* Parser::CurrentRationalLiteral() const {
+  literal_token_ ^= tokens_iterator_.CurrentToken();
+  ASSERT(literal_token_.kind() == Token::kRATIONAL);
+  return Fraction::RawCast(literal_token_.value());
+}
+
+
 struct ParamDesc {
   ParamDesc()
       : type(NULL),
@@ -4524,6 +4531,7 @@ void Parser::ParseClassDeclaration(const GrowableObjectArray& pending_classes,
       // Not patching a class, but it has been found. This must be one of the
       // pre-registered classes from object.cc or a duplicate definition.
       if (!(cls.is_prefinalized() ||
+            cls.is_refinalize_after_patch() ||  // TODO(regis): Remove.
             RawObject::IsImplicitFieldClassId(cls.id()))) {
         ReportError(classname_pos, "class '%s' is already defined",
                     class_name.ToCString());
@@ -7928,6 +7936,9 @@ bool Parser::IsSimpleLiteral(const AbstractType& type, Instance* value) {
   if (CurrentToken() == Token::kINTEGER) {
     *value = CurrentIntegerLiteral();
     return true;
+  } else if (CurrentToken() == Token::kRATIONAL) {
+    *value = CurrentRationalLiteral();
+    return true;
   } else if (CurrentToken() == Token::kDOUBLE) {
     *value = CurrentDoubleLiteral();
     return true;
@@ -14083,6 +14094,14 @@ AstNode* Parser::ParsePrimary() {
     primary = ParseExpr(kAllowConst, kConsumeCascades);
     SetAllowFunctionLiterals(saved_mode);
     ExpectToken(Token::kRPAREN);
+  } else if (token == Token::kRATIONAL) {
+    const Fraction& rational_value =
+        Fraction::ZoneHandle(Z, CurrentRationalLiteral());
+    if (rational_value.IsNull()) {
+      ReportError("invalid rational literal");
+    }
+    primary = new(Z) LiteralNode(TokenPos(), rational_value);
+    ConsumeToken();
   } else if (token == Token::kDOUBLE) {
     const Double& double_value = Double::ZoneHandle(Z, CurrentDoubleLiteral());
     if (double_value.IsNull()) {
@@ -14376,6 +14395,7 @@ void Parser::SkipPrimary() {
     case Token::kTRUE:
     case Token::kFALSE:
     case Token::kINTEGER:
+    case Token::kRATIONAL:
     case Token::kDOUBLE:
       ConsumeToken();
       break;