Support for a.b.c.d extract property sequence.

pkg/analyzer/lib/src/summary/link.dart

 // Copyright (c) 2016, 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.
 
 /**
  * This library is capable of producing linked summaries from unlinked
  * ones (or prelinked ones).  It functions by building a miniature
  * element model to represent the contents of the summaries, and then
  * scanning the element model to gather linked information and adding
  * it to the summary data structures.
@@ skipping 3259 matching lines @@
 
   @override
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 /**
  * Element representing a getter or setter resynthesized from a summary during
  * linking.
  */
 abstract class PropertyAccessorElementForLink
-    implements PropertyAccessorElementImpl {
+    implements PropertyAccessorElementImpl, ReferenceableElementForLink {
   void link(CompilationUnitElementInBuildUnit compilationUnit);
 }
 
 /**
  * Specialization of [PropertyAccessorElementForLink] for non-synthetic
  * accessors explicitly declared in the source code.
  */
 class PropertyAccessorElementForLink_Executable extends ExecutableElementForLink
     implements PropertyAccessorElementForLink {
   @override
@@ skipping 36 matching lines @@
     implements PropertyAccessorElementForLink {
   @override
   final bool isSetter;
 
   final VariableElementForLink _variable;
   FunctionTypeImpl _type;
 
   PropertyAccessorElementForLink_Variable(this._variable, this.isSetter);
 
   @override
+  DartType get asStaticType => returnType;
+
+  @override
+  TypeInferenceNode get asTypeInferenceNode {
+    // TODO(scheglov) is this correct?

[Paul Berry, 2016/04/15 21:15:52]

Yes, I believe this is correct, but only because of a shortcut I took earlier in
the linker implementation.  We always call asTypeInferenceNode on the return
value of getContainedName(), and getContainedName() never returns accessors; it
returns top level variable elements or fields.

This is awkward and not really in line with Dart semantics; really
getContainedName() should return the accessor, and then
PropertyAccessorElementForLink_Variable should return
_variable._typeInferenceNode.

But I think we can wait until a future CL to clean this up :)

+    return null;
+  }
+
+  @override
   Element get enclosingElement => _variable.enclosingElement;
 
   @override
   bool get isGetter => !isSetter;
 
   @override
   bool get isStatic => _variable.isStatic;
 
   @override
   bool get isSynthetic => true;
@@ skipping 27 matching lines @@
 
   @override
   FunctionTypeImpl get type => _type ??= new FunctionTypeImpl(this);
 
   @override
   List<TypeParameterElement> get typeParameters {
     // TODO(paulberry): is this correct for fields in generic classes?
     return const [];
   }
 
+  ReferenceableElementForLink getContainedName(String name) {
+    DartType type = returnType;
+    if (type is InterfaceType) {
+      PropertyAccessorElement getter =
+          type.lookUpGetter(name, _variable.compilationUnit.library);
+      print('getter: $getter');

[Paul Berry, 2016/04/15 21:15:52]

Looks like temporary debugging code; should be removed before committing.

+      if (getter is PropertyAccessorElementForLink) {
+        return getter;
+      }
+    }
+    return new NonstaticMemberElementForLink(null);
+  }
+
   @override
   bool isAccessibleIn(LibraryElement library) =>
       !Identifier.isPrivateName(name) || identical(this.library, library);
 
   @override
   void link(CompilationUnitElementInBuildUnit compilationUnit) {}
 
   @override
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 
@@ skipping 676 matching lines @@
    * there are no type parameters in scope.
    */
   TypeParameterizedElementForLink get _typeParameterContext;
 
   @override
   DartType buildType(DartType getTypeArgument(int i),
           List<int> implicitFunctionTypeIndices) =>
       DynamicTypeImpl.instance;
 
   ReferenceableElementForLink getContainedName(String name) {
+    DartType type = asStaticType;
+    if (type is InterfaceType) {
+      PropertyAccessorElement getter =
+          type.lookUpGetter(name, compilationUnit.library);
+      if (getter is PropertyAccessorElementForLink) {
+        return getter;
+      }
+    }
     return new NonstaticMemberElementForLink(_constNode);
   }
 
   @override
   noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }