Move Iterable implementation to collection.

sdk/lib/_collection_dev/iterable.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.dev;
 
 /**
  * An [Iterable] for classes that have efficient [length] and [elementAt].
  *
  * All other methods are implemented in terms of [length] and [elementAt],
  * including [iterator].
  */
-abstract class ListIterable<E> extends Iterable<E> {
+abstract class ListIterable<E> extends IterableBase<E> {
   int get length;
   E elementAt(int i);
 
   const ListIterable();
 
   Iterator<E> get iterator => new ListIterator<E>(this);
 
   void forEach(void action(E element)) {
     int length = this.length;
     for (int i = 0; i < length; i++) {
@@ skipping 267 matching lines @@
       return false;
     }
     _current = _iterable.elementAt(_index);
     _index++;
     return true;
   }
 }
 
 typedef T _Transformation<S, T>(S value);
 
-class MappedIterable<S, T> extends Iterable<T> {
+class MappedIterable<S, T> extends IterableBase<T> {
   final Iterable<S> _iterable;
   // TODO(ahe): Restore type when feature is implemented in dart2js
   // checked mode. http://dartbug.com/7733
   final /* _Transformation<S, T> */ _f;
 
   MappedIterable(this._iterable, T this._f(S element));
 
   Iterator<T> get iterator => new MappedIterator<S, T>(_iterable.iterator, _f);
 
   // Length related functions are independent of the mapping.
@@ skipping 37 matching lines @@
 
   MappedListIterable(this._source, T this._f(S value));
 
   int get length => _source.length;
   T elementAt(int index) => _f(_source.elementAt(index));
 }
 
 
 typedef bool _ElementPredicate<E>(E element);
 
-class WhereIterable<E> extends Iterable<E> {
+class WhereIterable<E> extends IterableBase<E> {
   final Iterable<E> _iterable;
   // TODO(ahe): Restore type when feature is implemented in dart2js
   // checked mode. http://dartbug.com/7733
   final /* _ElementPredicate */ _f;
 
   WhereIterable(this._iterable, bool this._f(E element));
 
   Iterator<E> get iterator => new WhereIterator<E>(_iterable.iterator, _f);
 }
 
@@ skipping 12 matching lines @@
       }
     }
     return false;
   }
 
   E get current => _iterator.current;
 }
 
 typedef Iterable<T> _ExpandFunction<S, T>(S sourceElement);
 
-class ExpandIterable<S, T> extends Iterable<T> {
+class ExpandIterable<S, T> extends IterableBase<T> {
   final Iterable<S> _iterable;
   // TODO(ahe): Restore type when feature is implemented in dart2js
   // checked mode. http://dartbug.com/7733
   final /* _ExpandFunction */ _f;
 
   ExpandIterable(this._iterable, Iterable<T> this._f(S element));
 
   Iterator<T> get iterator => new ExpandIterator<S, T>(_iterable.iterator, _f);
 }
 
@@ skipping 26 matching lines @@
         _currentExpansion = _f(_iterator.current).iterator;
       } else {
         return false;
       }
     }
     _current = _currentExpansion.current;
     return true;
   }
 }
 
-class TakeIterable<E> extends Iterable<E> {
+class TakeIterable<E> extends IterableBase<E> {
   final Iterable<E> _iterable;
   final int _takeCount;
 
   TakeIterable(this._iterable, this._takeCount) {
     if (_takeCount is! int || _takeCount < 0) {
       throw new ArgumentError(_takeCount);
     }
   }
 
   Iterator<E> get iterator {
@@ skipping 17 matching lines @@
     _remaining = -1;
     return false;
   }
 
   E get current {
     if (_remaining < 0) return null;
     return _iterator.current;
   }
 }
 
-class TakeWhileIterable<E> extends Iterable<E> {
+class TakeWhileIterable<E> extends IterableBase<E> {
   final Iterable<E> _iterable;
   // TODO(ahe): Restore type when feature is implemented in dart2js
   // checked mode. http://dartbug.com/7733
   final /* _ElementPredicate */ _f;
 
   TakeWhileIterable(this._iterable, bool this._f(E element));
 
   Iterator<E> get iterator {
     return new TakeWhileIterator<E>(_iterable.iterator, _f);
   }
@@ skipping 16 matching lines @@
     }
     return true;
   }
 
   E get current {
     if (_isFinished) return null;
     return _iterator.current;
   }
 }
 
-class SkipIterable<E> extends Iterable<E> {
+class SkipIterable<E> extends IterableBase<E> {
   final Iterable<E> _iterable;
   final int _skipCount;
 
   SkipIterable(this._iterable, this._skipCount) {
     if (_skipCount is! int || _skipCount < 0) {
       throw new ArgumentError(_skipCount);
     }
   }
 
   Iterable<E> skip(int n) {
@@ skipping 18 matching lines @@
 
   bool moveNext() {
     for (int i = 0; i < _skipCount; i++) _iterator.moveNext();
     _skipCount = 0;
     return _iterator.moveNext();
   }
 
   E get current => _iterator.current;
 }
 
-class SkipWhileIterable<E> extends Iterable<E> {
+class SkipWhileIterable<E> extends IterableBase<E> {
   final Iterable<E> _iterable;
   // TODO(ahe): Restore type when feature is implemented in dart2js
   // checked mode. http://dartbug.com/7733
   final /* _ElementPredicate */ _f;
 
   SkipWhileIterable(this._iterable, bool this._f(E element));
 
   Iterator<E> get iterator {
     return new SkipWhileIterator<E>(_iterable.iterator, _f);
   }
@@ skipping 17 matching lines @@
     }
     return _iterator.moveNext();
   }
 
   E get current => _iterator.current;
 }
 
 /**
  * The always empty [Iterable].
  */
-class EmptyIterable<E> extends Iterable<E> {
+class EmptyIterable<E> extends IterableBase<E> {
   const EmptyIterable();
 
   Iterator<E> get iterator => const EmptyIterator();
 
   void forEach(void action(E element)) {}
 
   bool get isEmpty => true;
 
   int get length => 0;
 
@@ skipping 57 matching lines @@
 class EmptyIterator<E> implements Iterator<E> {
   const EmptyIterator();
   bool moveNext() => false;
   E get current => null;
 }
 
 /** An [Iterator] that can move in both directions. */
 abstract class BidirectionalIterator<T> implements Iterator<T> {
   bool movePrevious();
 }