Make Iterable more powerful (and lazy).

sdk/lib/core/list.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.
 
 /**
  * A [List] is an indexable collection with a length. It can be of
  * fixed size or extendable.
  */
 interface List<E> extends Collection<E>, Sequence<E>
                   default _ListImpl<E> {
@@ skipping 34 matching lines @@
   void set length(int newLength);
 
   /**
    * Adds [value] at the end of the list, extending the length by
    * one. Throws an [UnsupportedError] if the list is not
    * extendable.
    */
   void add(E value);
 
   /**
-   * Adds [value] at the end of the list, extending the length by
-   * one. Throws an [UnsupportedError] if the list is not
-   * extendable.
+   * Alias for [add].

[Lasse Reichstein Nielsen, 2012/11/12 09:38:03]

Remove it.
It's slightly misnamed (other operations named 'last' refer to the current last
element, this one adds a new one) and redundant.
Adding at the end is what lists are all about.

    */
   void addLast(E value);
 
   /**
    * Appends all elements of the [collection] to the end of this list.
    * Extends the length of the list by the number of elements in [collection].
    * Throws an [UnsupportedError] if this list is not
    * extendable.
    */
   void addAll(Collection<E> collection);
@@ skipping 54 matching lines @@
    */
   E removeLast();
 
   /**
    * Returns the last element of the list, or throws an out of bounds
    * exception if the list is empty.
    */
   E get last;
 
   /**
+   * Returns a read-only view of [this].
+   *
+   * The returned [List] will be backed by [this], but cannot change [this].
+   */
+  List<E> get view;

[Lasse Reichstein Nielsen, 2012/11/12 09:38:03]

I still don't think 'view' signifies something inherently read-only. A view is
just something backed by something else. There is nothing preventing a "view"
from being write-through. I would prefer 'asUnmodifiable'

Please use "unmodifiable" consistently about collections that can't be modified.

+
+  /**
    * Returns a new list containing [length] elements from the list,
    * starting at  [start].
    * Returns an empty list if [length] is 0.
    * Throws an [ArgumentError] if [length] is negative.
    * Throws an [RangeError] if [start] or
    * [:start + length - 1:] are out of range.
    */
   List<E> getRange(int start, int length);
 
   /**
@@ skipping 42 matching lines @@
   external factory List([int length]);
 
   /**
    * Factory implementation of List.from().
    *
    * Creates a list with the elements of [other]. The order in
    * the list will be the order provided by the iterator of [other].
    */
   external factory List.from(Iterable<E> other);
 }