Introduce JsStrategy skeleton

pkg/compiler/lib/src/common_elements.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.
 
 // TODO(sigmund): rename and move to common/elements.dart
 library dart2js.type_system;
 
 import 'common/names.dart' show Identifiers, Uris;
 import 'constants/values.dart';
 import 'elements/entities.dart';
@@ skipping 141 matching lines @@
   ConstructorEntity get symbolConstructorTarget {
     // TODO(johnniwinther): Kernel does not include redirecting factories
     // so this cannot be found in kernel. Find a consistent way to handle
     // this and similar cases.
     return _symbolConstructorTarget ??=
         _findConstructor(symbolImplementationClass, '');
   }
 
   /// Whether [element] is the same as [symbolConstructor]. Used to check
   /// for the constructor without computing it until it is likely to be seen.
-  // TODO(johnniwinther): Change type of [e] to [MemberEntity].
-  bool isSymbolConstructor(Entity e) {
-    return e == symbolConstructorTarget ||
-        e == _findConstructor(symbolClass, '', required: false);
+  bool isSymbolConstructor(ConstructorEntity element) {
+    return element == symbolConstructorTarget ||
+        element == _findConstructor(symbolClass, '', required: false);
   }
 
   /// The `MirrorSystem` class in dart:mirrors.
   ClassEntity _mirrorSystemClass;
   ClassEntity get mirrorSystemClass => _mirrorSystemClass ??=
       _findClass(mirrorsLibrary, 'MirrorSystem', required: false);
 
   /// Whether [element] is `MirrorClass.getName`. Used to check for the use of
   /// that static method without forcing the resolution of the `MirrorSystem`
   /// class until it is necessary.
@@ skipping 150 matching lines @@
   ///
   /// If no type argument is provided, the canonical raw type is returned.
   InterfaceType streamType([DartType elementType]) {
     if (elementType == null) {
       return _getRawType(streamClass);
     }
     return _createInterfaceType(streamClass, [elementType]);
   }
 
   /// Returns `true` if [element] is a superclass of `String` or `num`.
-  // TODO(johnniwinther): Change types to `ClassEntity` when these are not
-  // called with unrelated elements.
-  bool isNumberOrStringSupertype(/*Class*/ Entity element) {
+  bool isNumberOrStringSupertype(ClassEntity element) {
     return element == _findClass(coreLibrary, 'Comparable', required: false);
   }
 
   /// Returns `true` if [element] is a superclass of `String`.
-  // TODO(johnniwinther): Change types to `ClassEntity` when these are not
-  // called with unrelated elements.
-  bool isStringOnlySupertype(/*Class*/ Entity element) {
+  bool isStringOnlySupertype(ClassEntity element) {
     return element == _findClass(coreLibrary, 'Pattern', required: false);
   }
 
   /// Returns `true` if [element] is a superclass of `List`.
   bool isListSupertype(ClassEntity element) => element == iterableClass;
 
   ClassEntity _findClass(LibraryEntity library, String name,
       {bool required: true}) {
     if (library == null) return null;
     return _env.lookupClass(library, name, required: required);
@@ skipping 919 matching lines @@
   // TODO(johnniwinther): Remove this when the resolver is removed.
   DartType getUnaliasedType(DartType type);
 
   /// Returns `true` if [member] a the synthetic getter `loadLibrary` injected
   /// on deferred libraries.
   bool isDeferredLoadLibraryGetter(MemberEntity member);
 
   /// Returns the metadata constants declared on [member].
   Iterable<ConstantValue> getMemberMetadata(MemberEntity member);
 }