Use iterator, moveNext(), current.

sdk/lib/_internal/compiler/implementation/util/link.dart

 // Copyright (c) 2011, 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.
 
 part of org_dartlang_compiler_util;
 
 class Link<T> extends Iterable<T> {
   T get head => null;
   Link<T> get tail => null;
 
@@ skipping 16 matching lines @@
     return link;
   }
 
   const Link();
 
   Link<T> prepend(T element) {
     // TODO(ahe): Use new Link<T>, but this cost 8% performance on VM.
     return new LinkEntry<T>(element, this);
   }
 
-  Iterator<T> iterator() => new LinkIterator<T>(this);
+  Iterator<T> get iterator => new LinkIterator<T>(this);
 
   void printOn(StringBuffer buffer, [separatedBy]) {
   }
 
   List toList() => new List<T>(0);
 
   bool get isEmpty => true;
 
   Link<T> reverse() => this;
 
@@ skipping 13 matching lines @@
 }
 
 interface LinkBuilder<T> default LinkBuilderImplementation<T> {
   LinkBuilder();
 
   Link<T> toLink();
   void addLast(T t);
 
   final int length;
 }