Runtime support for the new parameter specification.

lib/compiler/implementation/resolver.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.
 
 interface TreeElements {
   Element operator[](Node node);
   Selector getSelector(Send send);
   DartType getType(TypeAnnotation annotation);
   bool isParameterChecked(Element element);
 }
@@ skipping 2305 matching lines @@
   }
 }
 
 /**
  * [SignatureResolver] resolves function signatures.
  */
 class SignatureResolver extends CommonResolverVisitor<Element> {
   final Element enclosingElement;
   Link<Element> optionalParameters = const EmptyLink<Element>();
   int optionalParameterCount = 0;
+  bool optionalParametersAreNamed = false;
   VariableDefinitions currentDefinitions;
 
   SignatureResolver(Compiler compiler, this.enclosingElement) : super(compiler);
 
   Element visitNodeList(NodeList node) {
     // This must be a list of optional arguments.
     String value = node.beginToken.stringValue;
     if ((value !== '[') && (value !== '{')) {
       internalError(node, "expected optional parameters");
     }
+    optionalParametersAreNamed = (value === '{');
     LinkBuilder<Element> elements = analyzeNodes(node.nodes);
     optionalParameterCount = elements.length;
     optionalParameters = elements.toLink();
     return null;
   }
 
   Element visitVariableDefinitions(VariableDefinitions node) {
     Link<Node> definitions = node.definitions.nodes;
     if (definitions.isEmpty()) {
       cancel(node, 'internal error: no parameter definition');
@@ skipping 137 matching lines @@
       LinkBuilder<Element> parametersBuilder =
         visitor.analyzeNodes(formalParameters.nodes);
       requiredParameterCount  = parametersBuilder.length;
       parameters = parametersBuilder.toLink();
     }
     DartType returnType = compiler.resolveTypeAnnotation(element, returnNode);
     return new FunctionSignature(parameters,
                                  visitor.optionalParameters,
                                  requiredParameterCount,
                                  visitor.optionalParameterCount,
+                                 visitor.optionalParametersAreNamed,
                                  returnType);
   }
 
   // TODO(ahe): This is temporary.
   void resolveExpression(Node node) {
     if (node == null) return;
     node.accept(new ResolverVisitor(compiler, enclosingElement));
   }
 
   // TODO(ahe): This is temporary.
@@ skipping 253 matching lines @@
 
   Element localLookup(SourceString name) => library.find(name);
   Element lookup(SourceString name) => localLookup(name);
   Element lexicalLookup(SourceString name) => localLookup(name);
 
   Element add(Element newElement) {
     throw "Cannot add an element in the top scope";
   }
   String toString() => '$element';
 }