Extension method support to move us closer to a valid List implementation.

tool/input_sdk/lib/core/iterable.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 dart.core;
 
 /**
  * An object that uses an [Iterator] to serve objects one at a time.
  *
  * You can iterate over all objects served by an Iterable object
@@ skipping 13 matching lines @@
  *
  * You can implement Iterable in your own class.
  * If you do, then an instance of your Iterable class
  * can be the right-hand side of a for-in construct.
  *
  * Some subclasss of [Iterable] can be modified. It is generally not allowed
  * to modify such collections while they are being iterated. Doing so will break
  * the iteration, which is typically signalled by throwing a
  * [ConcurrentModificationError] when it is detected.
  */
+@SupportJsExtensionMethods()
 abstract class Iterable<E> {
   const Iterable();
 
   /**
    * Creates an Iterable that generates its elements dynamically.
    *
    * The Iterators created by the Iterable count from
    * zero to [:count - 1:] while iterating, and call [generator]
    * with that index to create the next value.
    *
@@ skipping 326 matching lines @@
  */
 abstract class BidirectionalIterator<E> implements Iterator<E> {
   /**
    * Move back to the previous element.
    *
    * Returns true and updates [current] if successful. Returns false
    * and sets [current] to null if there is no previous element.
    */
   bool movePrevious();
 }