| // Copyright (c) 2013, 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; |
| |
| |
| |
| class HashSet<E> extends Collection<E> implements Set<E> { |
| // The map backing this set. The associations in this map are all |
| // of the form element -> element. If a value is not in the map, |
| // then it is not in the set. |
| final _HashMapImpl<E, E> _backingMap; |
| |
| HashSet() : _backingMap = new _HashMapImpl<E, E>(); |
| |
| /** |
| * Creates a [Set] that contains all elements of [other]. |
| */ |
| factory HashSet.from(Iterable<E> other) { |
| Set<E> set = new HashSet<E>(); |
| for (final e in other) { |
| set.add(e); |
| } |
| return set; |
| } |
| |
| void clear() { |
| _backingMap.clear(); |
| } |
| |
| void add(E value) { |
| _backingMap[value] = value; |
| } |
| |
| bool remove(Object value) { |
| if (!_backingMap.containsKey(value)) return false; |
| _backingMap.remove(value); |
| return true; |
| } |
| |
| bool contains(E value) { |
| return _backingMap.containsKey(value); |
| } |
| |
| Set<E> intersection(Collection<E> collection) { |
| Set<E> result = new Set<E>(); |
| collection.forEach((E value) { |
| if (contains(value)) result.add(value); |
| }); |
| return result; |
| } |
| |
| bool isSubsetOf(Collection<E> other) { |
| return new Set<E>.from(other).containsAll(this); |
| } |
| |
| bool containsAll(Collection<E> collection) { |
| return collection.every((E value) { |
| return contains(value); |
| }); |
| } |
| |
| void forEach(void f(E element)) { |
| _backingMap.forEach((E key, E value) { |
| f(key); |
| }); |
| } |
| |
| bool get isEmpty { |
| return _backingMap.isEmpty; |
| } |
| |
| int get length { |
| return _backingMap.length; |
| } |
| |
| Iterator<E> get iterator => new _HashSetIterator<E>(this); |
| |
| String toString() { |
| return Collections.collectionToString(this); |
| } |
| } |
| |
| class _HashSetIterator<E> implements Iterator<E> { |
| |
| _HashSetIterator(HashSet<E> set) |
| : _keysIterator = set._backingMap._keys.iterator; |
| |
| E get current { |
| var result = _keysIterator.current; |
| if (identical(result, _HashMapImpl._DELETED_KEY)) { |
| // TODO(floitsch): improve the error reporting. |
| throw new StateError("Concurrent modification."); |
| } |
| return result; |
| } |
| |
| bool moveNext() { |
| bool result; |
| do { |
| result = _keysIterator.moveNext(); |
| } while (result && |
| (_keysIterator.current == null || |
| identical(_keysIterator.current, _HashMapImpl._DELETED_KEY))); |
| return result; |
| } |
| |
| Iterator _keysIterator; |
| } |