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

sdk/lib/core/set.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;
 
 /**
  * A collection of objects in which each object can occur only once.
  *
  * That is, for each object of the element type, the object is either considered
@@ skipping 37 matching lines @@
    * Creates an empty identity [Set].
    *
    * The created [Set] is a [LinkedHashSet] that uses identity as equality
    * relation.
    *
    * The set is equivalent to one created by `new LinkedHashSet<E>.identity()`.
    */
   factory Set.identity() = LinkedHashSet<E>.identity;
 
   /**
-   * Creates a [Set] that contains all elements of [other].
+   * Creates a [Set] that contains all of [elements].
+   *
+   * All the [elements] should be assignable to [E].
+   * The `elements` iterable itself can have any type,
+   * so this constructor can be used to down-cast a `Set`, for example as:
+   *
+   *     Set<SuperType> superSet = ...;
+   *     Set<SubType> subSet =
+   *         new Set<SubType>.from(superSet.where((e) => e is SubType));
    *
    * The created [Set] is a [LinkedHashSet]. As such, it considers elements that
-   * are equal (using [==]) to be undistinguishable, and requires them to
+   * are equal (using [==]) to be indistinguishable, and requires them to
    * have a compatible [Object.hashCode] implementation.
    *
-   * The set is equivalent to one created by `new LinkedHashSet<E>.from(other)`.
+   * The set is equivalent to one created by
+   * `new LinkedHashSet<E>.from(elements)`.
    */
-  factory Set.from(Iterable<E> other) = LinkedHashSet<E>.from;
+  factory Set.from(Iterable elements) = LinkedHashSet<E>.from;
 
   /**
    * Provides an iterator that iterates over the elements of this set.
    *
    * The order of iteration is defined by the individual `Set` implementation,
    * but must be consistent between changes to the set.
    */
   Iterator<E> get iterator;
 
   /**
@@ skipping 93 matching lines @@
   /* Creates a [Set] with the same elements and behavior as this `Set`.
    *
    * The returned set behaves the same as this set
    * with regard to adding and removing elements.
    * It initially contains the same elements.
    * If this set specifies an ordering of the elements,
    * the returned set will have the same order.
    */
   Set<E> toSet();
 }