Parse and resolve new syntax for named parameters.

dart/lib/compiler/implementation/scanner/parser.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /**
  * An event generating parser of Dart programs. This parser expects
  * all tokens in a linked list (aka a token stream).
  *
  * The class [Scanner] is used to generate a token stream. See the
  * file scanner.dart.
@@ skipping 124 matching lines @@
     listener.beginFormalParameters(begin);
     expect('(', token);
     int parameterCount = 0;
     if (optional(')', token.next)) {
       listener.endFormalParameters(parameterCount, begin, token.next);
       return token.next.next;
     }
     do {
       ++parameterCount;
       token = token.next;
-      if (optional('[', token)) {
-        token = parseOptionalFormalParameters(token);
+      String value = token.stringValue;
+      if (value === '[') {
+        token = parseOptionalFormalParameters(token, false);
+        break;
+      } else if (value === '{') {
+        token = parseOptionalFormalParameters(token, true);
         break;
       }
       token = parseFormalParameter(token);
     } while (optional(',', token));
     listener.endFormalParameters(parameterCount, begin, token);
     return expect(')', token);
   }
 
   Token parseFormalParameter(Token token) {
     listener.beginFormalParameter(token);
     token = parseModifiers(token);
     // TODO(ahe): Validate that there are formal parameters if void.
     token = parseReturnTypeOpt(token);
     Token thisKeyword = null;
     if (optional('this', token)) {
       thisKeyword = token;
       // TODO(ahe): Validate field initializers are only used in
       // constructors, and not for function-typed arguments.
       token = expect('.', token.next);
     }
     token = parseIdentifier(token);
     if (optional('(', token)) {
       token = parseFormalParameters(token);
       listener.handleFunctionTypedFormalParameter(token);
     }
-    if (optional('=', token)) {
+    String value = token.stringValue;
+    if (('=' === value) || (':' === value)) {
       // TODO(ahe): Validate that these are only used for optional parameters.
       Token equal = token;
       token = parseExpression(token.next);
       listener.handleValuedFormalParameter(equal, token);
     }
     listener.endFormalParameter(token, thisKeyword);
     return token;
   }
 
-  Token parseOptionalFormalParameters(Token token) {
+  Token parseOptionalFormalParameters(Token token, bool isNamed) {
     Token begin = token;
     listener.beginOptionalFormalParameters(begin);
-    assert(optional('[', token));
+    assert((isNamed && optional('{', token)) || optional('[', token));
     int parameterCount = 0;
     do {
       token = token.next;
       token = parseFormalParameter(token);
       ++parameterCount;
     } while (optional(',', token));
     listener.endOptionalFormalParameters(parameterCount, begin, token);
-    return expect(']', token);
+    if (isNamed) {
+      return expect('}', token);
+    } else {
+      return expect(']', token);
+    }
   }
 
   Token parseTypeOpt(Token token) {
     String value = token.stringValue;
     if (value === 'var') return parseType(token);
     if (value !== 'this') {
       Token peek = peekAfterExpectedType(token);
       if (isIdentifier(peek) || optional('this', peek)) {
         return parseType(token);
       }
@@ skipping 1642 matching lines @@
     }
     listener.handleContinueStatement(hasTarget, continueKeyword, token);
     return expectSemicolon(token);
   }
 
   Token parseEmptyStatement(Token token) {
     listener.handleEmptyStatement(token);
     return expectSemicolon(token);
   }
 }