Change List/Set/Map/Queue.from constructrs to accept any iterable.

sdk/lib/collection/queue.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.collection;
 
 /**
  * A [Queue] is a collection that can be manipulated at both ends. One
  * can iterate over the elements of a queue through [forEach] or with
  * an [Iterator].
  *
  * It is generally not allowed to modify the queue (add or remove entries) while
  * an operation on the queue is being performed, for example during a call to
  * [forEach].
  * Modifying the queue while it is being iterated will most likely break the
  * iteration.
  * This goes both for using the [iterator] directly, or for iterating an
  * `Iterable` returned by a method like [map] or [where].
  */
 abstract class Queue<E> implements Iterable<E>, EfficientLength {
 
   /**
    * Creates a queue.
    */
   factory Queue() = ListQueue<E>;
 
   /**
-   * Creates a queue with the elements of [other]. The order in
-   * the queue will be the order provided by the iterator of [other].
+   * Creates a queue containing all of [elements].
+   *
+   * The element order in the queue is as if the elements were added using
+   * [addLast] in the order provided by [elements.iterator].
    */
-  factory Queue.from(Iterable<E> other) = ListQueue<E>.from;
+  factory Queue.from(Iterable elements) = ListQueue<E>.from;
 
   /**
    * Removes and returns the first element of this queue.
    *
    * The queue must not be empty when this method is called.
    */
   E removeFirst();
 
   /**
    * Removes and returns the last element of the queue.
@@ skipping 146 matching lines @@
  * Allows constant time add, remove-at-ends and peek operations.
  */
 class DoubleLinkedQueue<E> extends IterableBase<E> implements Queue<E> {
   _DoubleLinkedQueueEntrySentinel<E> _sentinel;
   int _elementCount = 0;
 
   DoubleLinkedQueue() {
     _sentinel = new _DoubleLinkedQueueEntrySentinel<E>();
   }
 
-  factory DoubleLinkedQueue.from(Iterable<E> other) {
+  /**
+   * Creates a double-linked queue containing all of [elements].
+   *
+   * The element order in the queue is as if the elements were added using
+   * [addLast] in the order provided by [elements.iterator].
+   */
+  factory DoubleLinkedQueue.from(Iterable elements) {
     Queue<E> list = new DoubleLinkedQueue();
-    for (final e in other) {
+    for (final E e in elements) {
       list.addLast(e);
     }
     return list;
   }
 
   int get length => _elementCount;
 
   void addLast(E value) {
     _sentinel.prepend(value);
     _elementCount++;
@@ skipping 160 matching lines @@
     if (initialCapacity == null || initialCapacity < _INITIAL_CAPACITY) {
       initialCapacity = _INITIAL_CAPACITY;
     } else if (!_isPowerOf2(initialCapacity)) {
       initialCapacity = _nextPowerOf2(initialCapacity);
     }
     assert(_isPowerOf2(initialCapacity));
     _table = new List<E>(initialCapacity);
   }
 
   /**
-   * Create a queue initially containing the elements of [source].
+   * Create a `ListQueue` containing all of [elements].
+   *
+   * The elements are added to the queue, as by [addLast], in the order given by
+   * `elements.iterator`.
+   *
+   * All `elements` should be assignable to [E].
    */
-  factory ListQueue.from(Iterable<E> source) {
-    if (source is List) {
-      int length = source.length;
+  factory ListQueue.from(Iterable elements) {
+    if (elements is List) {
+      int length = elements.length;
       ListQueue<E> queue = new ListQueue(length + 1);
       assert(queue._table.length > length);
-      List sourceList = source;
+      List sourceList = elements;
       queue._table.setRange(0, length, sourceList, 0);
       queue._tail = length;
       return queue;
     } else {
-      return new ListQueue<E>()..addAll(source);
+      int capacity = _INITIAL_CAPACITY;
+      if (elements is EfficientLength) {
+        capacity = elements.length;
+      }
+      ListQueue<E> result = new ListQueue<E>(capacity);
+      for (final E element in elements) {
+        result.addLast(element);
+      }
+      return result;
     }
   }
 
   // Iterable interface.
 
   Iterator<E> get iterator => new _ListQueueIterator<E>(this);
 
   void forEach(void action (E element)) {
     int modificationCount = _modificationCount;
     for (int i = _head; i != _tail; i = (i + 1) & (_table.length - 1)) {
@@ skipping 308 matching lines @@
     _queue._checkModification(_modificationCount);
     if (_position == _end) {
       _current = null;
       return false;
     }
     _current = _queue._table[_position];
     _position = (_position + 1) & (_queue._table.length - 1);
     return true;
   }
 }