Begin to compute constant expressions in resolution.

pkg/compiler/lib/src/core_types.dart

 // Copyright (c) 2014, 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.
 
 library dart2js.type_system;
 
 import 'dart_types.dart';
 import 'elements/elements.dart' show ClassElement;
 
 /// The core types in Dart.
 abstract class CoreTypes {
   /// The `Object` type defined in 'dart:core'.
   InterfaceType get objectType;
 
   /// The `bool` type defined in 'dart:core'.
   InterfaceType get boolType;
 
   /// The `bool` type defined in 'dart:core'.
   InterfaceType get numType;
 
   /// The `int` type defined in 'dart:core'.
   InterfaceType get intType;
 
   /// The `double` type defined in 'dart:core'.
   InterfaceType get doubleType;
 
   /// The `String` type defined in 'dart:core'.
   InterfaceType get stringType;
 
+  /// The `Symbol` type defined in 'dart:core'.
+  InterfaceType get symbolType;
+
   /// The `Function` type defined in 'dart:core'.
   InterfaceType get functionType;
 
   /// The `Null` type defined in 'dart:core'.
   InterfaceType get nullType;
 
   /// The `Type` type defined in 'dart:core'.
   InterfaceType get typeType;
 
   /// Returns an instance of the `List` type defined in 'dart:core' with
   /// [elementType] as its type argument.
-  InterfaceType listType([DartType elementType = const DynamicType()]);
+  ///
+  /// If no type argument is provided, the canonical raw type is returned.
+  InterfaceType listType([DartType elementType]);
 
   /// Returns an instance of the `Map` type defined in 'dart:core' with
   /// [keyType] and [valueType] as its type arguments.
-  InterfaceType mapType([DartType keyType = const DynamicType(),
-                         DartType valueType = const DynamicType()]);
+  ///
+  /// If no type arguments are provided, the canonical raw type is returned.
+  InterfaceType mapType([DartType keyType, DartType valueType]);
 
   /// Returns an instance of the `Iterable` type defined in 'dart:core' with
   /// [elementType] as its type argument.
-  InterfaceType iterableType([DartType elementType = const DynamicType()]);
+  ///
+  /// If no type argument is provided, the canonical raw type is returned.
+  InterfaceType iterableType([DartType elementType]);
 
   /// The `Future` class declaration.
   ClassElement get futureClass;
 
   /// Returns an instance of the `Future` type defined in 'dart:async' with
   /// [elementType] as its type argument.
-  InterfaceType futureType([DartType elementType = const DynamicType()]);
+  ///
+  /// If no type argument is provided, the canonical raw type is returned.
+  InterfaceType futureType([DartType elementType]);
 
   /// Returns an instance of the `Stream` type defined in 'dart:async' with
   /// [elementType] as its type argument.
-  InterfaceType streamType([DartType elementType = const DynamicType()]);
+  ///
+  /// If no type argument is provided, the canonical raw type is returned.
+  InterfaceType streamType([DartType elementType]);
 }