Add reduce to Collection.

runtime/lib/array.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.
 
 class ListFactory<E> {
 
   factory List.from(Iterable<E> other) {
     GrowableObjectArray<E> list = new GrowableObjectArray<E>();
     for (final e in other) {
       list.add(e);
@@ skipping 70 matching lines @@
    */
 
   void forEach(f(E element)) {
     Collections.forEach(this, f);
   }
 
   Collection map(f(E element)) {
     return Collections.map(this, new GrowableObjectArray.withCapacity(length), f);
   }
 
+  Dynamic reduce(Dynamic initialValue,
+                 Dynamic combine(Dynamic previousValue, E element)) {
+    return Collections.reduce(this, initialValue, combine);
+  }
+
   Collection<E> filter(bool f(E element)) {
     return Collections.filter(this, new GrowableObjectArray<E>(), f);
   }
 
   bool every(bool f(E element)) {
     return Collections.every(this, f);
   }
 
   bool some(bool f(E element)) {
     return Collections.some(this, f);
@@ skipping 112 matching lines @@
    */
 
   void forEach(f(E element)) {
     Collections.forEach(this, f);
   }
 
   Collection map(f(E element)) {
     return Collections.map(this, new GrowableObjectArray.withCapacity(length), f);
   }
 
+  Dynamic reduce(Dynamic initialValue,
+                 Dynamic combine(Dynamic previousValue, E element)) {
+    return Collections.reduce(this, initialValue, combine);
+  }
+
   Collection<E> filter(bool f(E element)) {
     return Collections.filter(this, new GrowableObjectArray<E>(), f);
   }
 
   bool every(bool f(E element)) {
     return Collections.every(this, f);
   }
 
   bool some(bool f(E element)) {
     return Collections.some(this, f);
@@ skipping 75 matching lines @@
     if (!hasNext()) {
       throw const NoMoreElementsException();
     }
     return _array[_pos++];
   }
 
   final List<E> _array;
   final int _length;  // Cache array length for faster access.
   int _pos;
 }