Introduce ClassLike, MemberLike, FieldLike and FunctionLike

pkg/compiler/lib/src/world.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.
 
 library dart2js.world;
 
 import 'closure.dart' show SynthesizedCallMethodElementX;
 import 'common/backend_api.dart' show BackendClasses;
 import 'common.dart';
 import 'compiler.dart' show Compiler;
 import 'core_types.dart' show CoreClasses;
 import 'dart_types.dart';
 import 'elements/elements.dart'
     show
         ClassElement,
         Element,
         FunctionElement,
         MixinApplicationElement,
         TypedefElement,
-        VariableElement;
+        FieldElement;
 import 'js_backend/backend.dart' show JavaScriptBackend;
 import 'ordered_typeset.dart';
 import 'types/masks.dart' show CommonMasks, FlatTypeMask, TypeMask;
 import 'universe/class_set.dart';
 import 'universe/function_set.dart' show FunctionSet;
 import 'universe/selector.dart' show Selector;
 import 'universe/side_effects.dart' show SideEffects;
 import 'util/enumset.dart';
 import 'util/util.dart' show Link;
 
@@ skipping 226 matching lines @@
   /// Returns all resolved typedefs.
   Iterable<TypedefElement> get allTypedefs;
 
   /// Returns the single [Element] that matches a call to [selector] on a
   /// receiver of type [mask]. If multiple targets exist, `null` is returned.
   Element locateSingleElement(Selector selector, TypeMask mask);
 
   /// Returns the single field that matches a call to [selector] on a
   /// receiver of type [mask]. If multiple targets exist or the single target
   /// is not a field, `null` is returned.
-  VariableElement locateSingleField(Selector selector, TypeMask mask);
+  FieldElement locateSingleField(Selector selector, TypeMask mask);
 
   /// Returns the side effects of executing [element].
   SideEffects getSideEffectsOfElement(Element element);
 
   /// Returns the side effects of calling [selector] on a receiver of type
   /// [mask].
   SideEffects getSideEffectsOfSelector(Selector selector, TypeMask mask);
 
   /// Returns `true` if [element] is guaranteed not to throw an exception.
   bool getCannotThrow(Element element);
@@ skipping 781 matching lines @@
   bool hasAnyUserDefinedGetter(Selector selector, TypeMask mask) {
     return allFunctions.filter(selector, mask).any((each) => each.isGetter);
   }
 
   void registerUsedElement(Element element) {
     if (element.isInstanceMember && !element.isAbstract) {
       allFunctions.add(element);
     }
   }
 
-  VariableElement locateSingleField(Selector selector, TypeMask mask) {
+  FieldElement locateSingleField(Selector selector, TypeMask mask) {
     Element result = locateSingleElement(selector, mask);
     return (result != null && result.isField) ? result : null;
   }
 
   Element locateSingleElement(Selector selector, TypeMask mask) {
     mask ??= commonMasks.dynamicType;
     return mask.locateSingleElement(selector, _compiler);
   }
 
   TypeMask extendMaskIfReachesAll(Selector selector, TypeMask mask) {
@@ skipping 122 matching lines @@
   /// Only the class itself is included.
   EXACT,
 
   /// The class and all subclasses (transitively) are included.
   SUBCLASS,
 
   /// The class and all classes that implement or subclass it (transitively)
   /// are included.
   SUBTYPE,
 }