Support default values for optional parameters.

dart/frog/leg/emitter.dart

 // Copyright (c) 2011, 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.
 
 /**
  * Generates the code for all used classes in the program. Static fields (even
  * in classes) are ignored, since they can be treated as non-class elements.
  *
  * The code for the containing (used) methods must exist in the [:universe:].
  */
@@ skipping 29 matching lines @@
   void addParameterStub(FunctionElement member,
                         String prototype,
                         StringBuffer buffer,
                         Selector selector) {
     FunctionParameters parameters = member.computeParameters(compiler);
     int positionalArgumentCount = selector.positionalArgumentCount;
     if (positionalArgumentCount == parameters.parameterCount) {
       assert(selector.namedArgumentCount == 0);
       return;
     }
+    CompileTimeConstantHandler constants = compiler.compileTimeConstantHandler;
     List<SourceString> names = selector.getOrderedNamedArguments();
 
     String invocationName =
         namer.instanceMethodInvocationName(member.name, selector);
     buffer.add('$prototype.$invocationName = function(');
 
     // The parameters that this stub takes.
     List<String> parametersBuffer = new List<String>(selector.argumentCount);
     // The arguments that will be passed to the real method.
     List<String> argumentsBuffer = new List<String>(parameters.parameterCount);
@@ skipping 39 matching lines @@
         parametersBuffer[count] = jsName;
         argumentsBuffer[count] = jsName;
       } else {
         int index = names.indexOf(element.name);
         if (index != -1) {
           // The order of the named arguments is not the same as the
           // one in the real method (which is in Dart source order).
           argumentsBuffer[count] = jsName;
           parametersBuffer[selector.positionalArgumentCount + index] = jsName;
         } else {
-          // TODO(ngeoffray): Get the default value.
-          argumentsBuffer[count] = '(void 0)';
+          argumentsBuffer[count] = constants.getJsCodeForVariable(element);
         }
       }
       count++;
     });
 
     buffer.add('${Strings.join(parametersBuffer, ",")}) {\n');
     buffer.add('  return this.${namer.getName(member)}');
     buffer.add('(${Strings.join(argumentsBuffer, ",")})\n}\n');
   }
 
@@ skipping 139 matching lines @@
     //    function Isolate() {
     //       this.staticNonFinal = Isolate.prototype.someVal;
     //       ...
     //    }
     CompileTimeConstantHandler constants = compiler.compileTimeConstantHandler;
     List<VariableElement> staticNonFinalFields =
         constants.getStaticNonFinalFieldsForEmission();
     if (!staticNonFinalFields.isEmpty()) buffer.add('\n');
     for (Element element in staticNonFinalFields) {
       buffer.add('  this.${namer.getName(element)} = ');
-      constants.emitJsCodeForField(element, buffer);
+      buffer.add(constants.getJsCodeForVariable(element));
       buffer.add(';\n');
     }
   }
 
   void emitStaticFinalFieldInitializations(StringBuffer buffer) {
     CompileTimeConstantHandler constants = compiler.compileTimeConstantHandler;
     List<VariableElement> staticFinalFields =
         constants.getStaticFinalFieldsForEmission();
     for (VariableElement element in staticFinalFields) {
       buffer.add('${namer.isolatePropertyAccess(element)} = ');
-      constants.emitJsCodeForField(element, buffer);
+      buffer.add(constants.getJsCodeForVariable(element));
       buffer.add(';\n');
     }
   }
 
   void emitNoSuchMethodCalls(StringBuffer buffer) {
     // Do not generate no such method calls if there is no class.
     if (compiler.universe.instantiatedClasses.isEmpty()) return;
 
     // TODO(ngeoffray): We don't need to generate these methods if
     // nobody overwrites noSuchMethod.
@@ skipping 51 matching lines @@
       emitStaticFunctions(buffer);
       emitStaticFinalFieldInitializations(buffer);
       buffer.add('var ${namer.CURRENT_ISOLATE} = new ${namer.ISOLATE}();\n');
       Element main = compiler.universe.find(Compiler.MAIN);
       buffer.add('${namer.isolateAccess(main)}();\n');
       compiler.assembledCode = buffer.toString();
     });
     return compiler.assembledCode;
   }
 }