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

sdk/lib/collection/hash_map.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 HashMap<K, V> extends _HashTable<K> implements Map<K, V> {
-  static const int _INITIAL_CAPACITY = 8;
-  static const int _VALUE_INDEX = 1;
-
-  HashMap() : super(_INITIAL_CAPACITY);
-
-  factory HashMap.from(Map<K, V> other) {
-    return new HashMap<K, V>()..addAll(other);
-  }
-
-  int get _entrySize => 2;
-
-  V _value(int offset) => _table[offset + _VALUE_INDEX];
-  void _setValue(int offset, V value) { _table[offset + _VALUE_INDEX] = value; }
-
-  _copyEntry(List fromTable, int fromOffset, int toOffset) {
-    _table[toOffset + _VALUE_INDEX] = fromTable[fromOffset + _VALUE_INDEX];
-  }
-
-  bool containsKey(K key) {
-    return _get(key) >= 0;
-  }
-
-  bool containsValue(V value) {
-    for (int offset = 0; offset < _table.length; offset += _entrySize) {
-      if (!_isFree(_table[offset]) && _value(offset) == value) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  void addAll(Map<K, V> other) {
-    other.forEach((K key, V value) {
-      int offset = _put(key);
-      _setValue(offset, value);
-      _checkCapacity();
-    });
-  }
-
-  V operator [](K key) {
-    int offset = _get(key);
-    if (offset >= 0) return _value(offset);
-    return null;
-  }
-
-  void operator []=(K key, V value) {
-    int offset = _put(key);
-    _setValue(offset, value);
-    _checkCapacity();
-  }
-
-  V putIfAbsent(K key, V ifAbsent()) {
-    int offset = _probeForAdd(_hashCodeOf(key), key);
-    Object entry = _table[offset];
-    if (!_isFree(entry)) {
-      return _value(offset);
-    }
-    int modificationCount = _modificationCount;
-    V value = ifAbsent();
-    _checkModification(modificationCount);
-    _setKey(offset, key);
-    _setValue(offset, value);
-    if (entry == null) {
-      _entryCount++;
-      _checkCapacity();
-    } else {
-      assert(identical(entry, _TOMBSTONE));
-      _deletedCount--;
-    }
-    _recordModification();
-    return value;
-  }
-
-  V remove(K key) {
-    int offset = _remove(key);
-    if (offset < 0) return null;
-    V oldValue = _value(offset);
-    _setValue(offset, null);
-    _checkCapacity();
-    return oldValue;
-  }
-
-  void clear() {
-    _clear();
-  }
-
-  void forEach(void action (K key, V value)) {
-    int modificationCount = _modificationCount;
-    for (int offset = 0; offset < _table.length; offset += _entrySize) {
-      Object entry = _table[offset];
-      if (!_isFree(entry)) {
-        K key = entry;
-        V value = _value(offset);
-        action(key, value);
-        _checkModification(modificationCount);
-      }
-    }
-  }
-
-  Iterable<K> get keys => new _HashTableKeyIterable<K>(this);
-  Iterable<V> get values =>
-      new _HashTableValueIterable<V>(this, _VALUE_INDEX);
-
-  int get length => _elementCount;
-
-  bool get isEmpty => _elementCount == 0;
-
-  String toString() => Maps.mapToString(this);
-}