Make mappedBy lazy.

sdk/lib/core/queue.dart

Index: sdk/lib/core/queue.dart
diff --git a/sdk/lib/core/queue.dart b/sdk/lib/core/queue.dart
index 15ebed34fb3d6790a161311d6285dc9761b30ec1..87462858176c29ba2818ed71d5c98836b66603aa 100644
--- a/sdk/lib/core/queue.dart
+++ b/sdk/lib/core/queue.dart
@@ -170,7 +170,7 @@ class _DoubleLinkedQueueEntrySentinel<E> extends DoubleLinkedQueueEntry<E> {
  * WARNING: This class is temporary located in dart:core. It'll be removed
  * at some point in the near future.
  */
-class DoubleLinkedQueue<E> implements Queue<E> {
+class DoubleLinkedQueue<E> extends Iterable<E> implements Queue<E> {
   _DoubleLinkedQueueEntrySentinel<E> _sentinel;
 
   DoubleLinkedQueue() {
@@ -227,12 +227,6 @@ class DoubleLinkedQueue<E> implements Queue<E> {
     return _sentinel.nextEntry();
   }
 
-  int get length {
-    int counter = 0;
-    forEach((E element) { counter++; });
-    return counter;
-  }
-
   bool get isEmpty {
     return (identical(_sentinel._next, _sentinel));
   }
@@ -242,15 +236,6 @@ class DoubleLinkedQueue<E> implements Queue<E> {
     _sentinel._previous = _sentinel;
   }
 
-  void forEach(void f(E element)) {
-    DoubleLinkedQueueEntry<E> entry = _sentinel._next;
-    while (!identical(entry, _sentinel)) {
-      DoubleLinkedQueueEntry<E> nextEntry = entry._next;
-      f(entry._element);
-      entry = nextEntry;
-    }
-  }
-
   void forEachEntry(void f(DoubleLinkedQueueEntry<E> element)) {
     DoubleLinkedQueueEntry<E> entry = _sentinel._next;
     while (!identical(entry, _sentinel)) {
@@ -260,53 +245,6 @@ class DoubleLinkedQueue<E> implements Queue<E> {
     }
   }
 
-  bool every(bool f(E element)) {
-    DoubleLinkedQueueEntry<E> entry = _sentinel._next;
-    while (!identical(entry, _sentinel)) {
-      DoubleLinkedQueueEntry<E> nextEntry = entry._next;
-      if (!f(entry._element)) return false;
-      entry = nextEntry;
-    }
-    return true;
-  }
-
-  bool some(bool f(E element)) {
-    DoubleLinkedQueueEntry<E> entry = _sentinel._next;
-    while (!identical(entry, _sentinel)) {
-      DoubleLinkedQueueEntry<E> nextEntry = entry._next;
-      if (f(entry._element)) return true;
-      entry = nextEntry;
-    }
-    return false;
-  }
-
-  Queue mappedBy(f(E element)) {
-    Queue other = new Queue();
-    DoubleLinkedQueueEntry<E> entry = _sentinel._next;
-    while (!identical(entry, _sentinel)) {
-      DoubleLinkedQueueEntry<E> nextEntry = entry._next;
-      other.addLast(f(entry._element));
-      entry = nextEntry;
-    }
-    return other;
-  }
-
-  Dynamic reduce(Dynamic initialValue,
-                 Dynamic combine(Dynamic previousValue, E element)) {
-    return Collections.reduce(this, initialValue, combine);
-  }
-
-  Queue<E> where(bool f(E element)) {
-    Queue<E> other = new Queue<E>();
-    DoubleLinkedQueueEntry<E> entry = _sentinel._next;
-    while (!identical(entry, _sentinel)) {
-      DoubleLinkedQueueEntry<E> nextEntry = entry._next;
-      if (f(entry._element)) other.addLast(entry._element);
-      entry = nextEntry;
-    }
-    return other;
-  }
-
   _DoubleLinkedQueueIterator<E> get iterator {
     return new _DoubleLinkedQueueIterator<E>(_sentinel);
   }