Add ElementX.declarationSite.

dart/site/try/poi/poi.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 trydart.poi;
 
 import 'dart:async' show
     Completer,
     Future,
     Stream;
@@ skipping 35 matching lines @@
     ClassElement,
     CompilationUnitElement,
     Element,
     ElementCategory,
     FunctionElement,
     LibraryElement,
     ScopeContainerElement;
 
 import 'package:compiler/implementation/elements/modelx.dart' as modelx;
 
+import 'package:compiler/implementation/elements/modelx.dart' show
+    DeclarationSite;
+
 import 'package:compiler/implementation/dart_types.dart' show
     DartType;
 
 import 'package:compiler/implementation/scanner/scannerlib.dart' show
     EOF_TOKEN,
     IDENTIFIER_TOKEN,
     KEYWORD_TOKEN,
     PartialClassElement,
     PartialElement,
     Token;
@@ skipping 257 matching lines @@
       return repeat();
     }
   });
 }
 
 /// Find the token corresponding to [position] in [element].  The method only
 /// works for instances of [PartialElement] or [LibraryElement].  Support for
 /// [LibraryElement] is currently limited, and works only for named libraries.
 Token findToken(modelx.ElementX element, int position) {
   Token beginToken;
-  if (element is PartialElement) {
-    beginToken = (element as PartialElement).beginToken;
-  } else if (element is PartialClassElement) {
-    beginToken = element.beginToken;
+  DeclarationSite site = element.declarationSite;
+  if (site is PartialElement) {
+    beginToken = site.beginToken;
   } else if (element.isLibrary) {
     // TODO(ahe): Generalize support for library elements (and update above
     // documentation).
     modelx.LibraryElementX lib = element;
     var tag = lib.libraryTag;
     if (tag != null) {
       beginToken = tag.libraryKeyword;
     }
   } else {
     beginToken = element.position;
@@ skipping 66 matching lines @@
   element.accept(visitor);
   return '${visitor.buffer}';
 }
 
 class FindPositionVisitor extends ElementVisitor {
   final int position;
   Element element;
 
   FindPositionVisitor(this.position, this.element);
 
-  visitElement(Element e) {
-    if (e is PartialElement) {
-      if ((e as PartialElement).beginToken.charOffset <= position &&
-          position < (e as PartialElement).endToken.next.charOffset) {
+  visitElement(modelx.ElementX e) {
+    DeclarationSite site = e.declarationSite;
+    if (site is PartialElement) {
+      if (site.beginToken.charOffset <= position &&
+          position < site.endToken.next.charOffset) {
         element = e;
       }
     }
   }
 
   visitClassElement(ClassElement e) {
     if (e is PartialClassElement) {
       if (e.beginToken.charOffset <= position &&
           position < e.endToken.next.charOffset) {
         element = e;
@@ skipping 269 matching lines @@
     buffer.write('\n');
     indented.write('}');
   }
 }
 
 modelx.ScopeX localScope(modelx.LibraryElementX element) => element.localScope;
 
 modelx.ImportScope importScope(modelx.LibraryElementX element) {
   return element.importScope;
 }