Revert "New implementation of {,Linked}Hash{Set,Map}."

sdk/lib/collection/hash_set.dart

-// 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> {
-  static const int _INITIAL_CAPACITY = 8;
-  final _HashTable<E> _table;
-
-  HashSet() : _table = new _HashTable(_INITIAL_CAPACITY);
-
-  factory HashSet.from(Iterable<E> iterable) {
-    return new HashSet<E>()..addAll(iterable);
-  }
-
-  // Iterable.
-  Iterator<E> get iterator => new _HashTableKeyIterator<E>(_table);
-
-  bool get isEmpty => _table._elementCount == 0;
-
-  bool contains(Object object) => _table._get(object) >= 0;
-
-  // Collection.
-  void add(E element) {
-    _table._put(element);
-    _table._checkCapacity();
-  }
-
-  void addAll(Iterable<E> objects) {
-    for (E object in objects) {
-      _table._put(object);
-      _table._checkCapacity();
-    }
-  }
-
-  bool remove(Object object) {
-    int offset = _table._remove(object);
-    _table._checkCapacity();
-    return offset >= 0;
-  }
-
-  void removeAll(Iterable objectsToRemove) {
-    for (Object object in objectsToRemove) {
-      _table._remove(object);
-      _table._checkCapacity();
-    }
-  }
-
-  void retainAll(Iterable objectsToRetain) {
-    IterableMixinWorkaround.retainAll(this, objectsToRetain);
-  }
-
-  void _filterMatching(bool test(E element), bool removeMatching) {
-    int entrySize = _table._entrySize;
-    int length = _table._table.length;
-    for (int offset =  0; offset < length; offset += entrySize) {
-      Object entry = _table._table[offset];
-      if (!_table._isFree(entry)) {
-        E key = identical(entry, _NULL) ? null : entry;
-        int modificationCount = _table._modificationCount;
-        bool remove = (removeMatching == test(key));
-        _table._checkModification(modificationCount);
-        if (remove) {
-          _table._deleteEntry(offset);
-        }
-      }
-    }
-    _table._checkCapacity();
-  }
-
-  void removeMatching(bool test(E element)) {
-    _filterMatching(test, true);
-  }
-
-  void retainMatching(bool test(E element)) {
-    _filterMatching(test, false);
-  }
-
-  void clear() {
-    _table._clear();
-  }
-
-  // Set.
-  bool isSubsetOf(Collection<E> collection) {
-    Set otherSet;
-    if (collection is Set) {
-      otherSet = collection;
-    } else {
-      otherSet = collection.toSet();
-    }
-    return otherSet.containsAll(this);
-  }
-
-  bool containsAll(Collection<E> collection) {
-    for (E element in collection) {
-      if (!this.contains(element)) return false;
-    }
-    return true;
-  }
-
-  Set<E> intersection(Collection<E> other) {
-    Set<E> result = new HashSet<E>();
-    for (E element in other) {
-      if (this.contains(element)) {
-        result.add(element);
-      }
-    }
-    return result;
-  }
-
-  String toString() =>  Collections.collectionToString(this);
-}