Updates to collection_patch.dart

tool/input_sdk/patch/collection_patch.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.
 
 // Patch file for dart:collection classes.
 import 'dart:_foreign_helper' show JS;
 import 'dart:_js_helper' show
-    fillLiteralMap, InternalMap, NoInline, NoThrows, patch, JsLinkedHashMap;
+    fillLiteralMap, InternalMap, NoInline, NoSideEffects, NoThrows, patch,
+    JsLinkedHashMap, LinkedHashMapCell, LinkedHashMapKeyIterable,
+    LinkedHashMapKeyIterator;
+
+const _USE_ES6_MAPS = true;
 
 @patch
 class HashMap<K, V> {
   @patch
   factory HashMap({ bool equals(K key1, K key2),
                     int hashCode(K key),
                     bool isValidKey(Object potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
@@ skipping 36 matching lines @@
   //
   // where all keys in the same bucket share the same hash code.
   var _strings;
   var _nums;
   var _rest;
 
   // When iterating over the hash map, it is very convenient to have a
   // list of all the keys. We cache that on the instance and clear the
   // the cache whenever the key set changes. This is also used to
   // guard against concurrent modifications.
-  List _keys;
+  List/*<K>*/ _keys;
 
   _HashMap();
 
 
   int get length => _length;
   bool get isEmpty => _length == 0;
   bool get isNotEmpty => !isEmpty;
 
   Iterable<K> get keys {
-    return new HashMapKeyIterable<K>(this);
+    return new _HashMapKeyIterable<K, V>(this);
   }
 
   Iterable<V> get values {
     return new MappedIterable<K, V>(keys, (each) => this[each]);
   }
 
   bool containsKey(Object key) {
     if (_isStringKey(key)) {
       var strings = _strings;
       return (strings == null) ? false : _hasTableEntry(strings, key);
@@ skipping 110 matching lines @@
   }
 
   void clear() {
     if (_length > 0) {
       _strings = _nums = _rest = _keys = null;
       _length = 0;
     }
   }
 
   void forEach(void action(K key, V value)) {
-    List keys = _computeKeys();
+    List/*<K>*/ keys = _computeKeys();
     for (int i = 0, length = keys.length; i < length; i++) {
       var key = JS('var', '#[#]', keys, i);
       action(key, this[key]);
       if (JS('bool', '# !== #', keys, _keys)) {
         throw new ConcurrentModificationError(this);
       }
     }
   }
 
-  List _computeKeys() {
+  List/*<K>*/ _computeKeys() {
     if (_keys != null) return _keys;
-    List result = new List(_length);
+    List/*<K>*/ result = new List/*<K>*/(_length);

[Leaf, 2016/05/18 20:11:54]

consider var?

[sra1, 2016/05/18 22:10:04]

Done.

     int index = 0;
 
     // Add all string keys to the list.
     var strings = _strings;
     if (strings != null) {
       var names = JS('var', 'Object.getOwnPropertyNames(#)', strings);
       int entries = JS('int', '#.length', names);
       for (int i = 0; i < entries; i++) {
         String key = JS('String', '#[#]', names, i);
         JS('void', '#[#] = #', result, index, key);
@@ skipping 104 matching lines @@
 
   static void _deleteTableEntry(var table, var key) {
     JS('void', 'delete #[#]', table, key);
   }
 
   List _getBucket(var table, var key) {
     var hash = _computeHashCode(key);
     return JS('var', '#[#]', table, hash);
   }
 
-  int _findBucketIndex(var bucket, var key) {
+  int _findBucketIndex(var bucket, Object key) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i += 2) {
       if (JS('var', '#[#]', bucket, i) == key) return i;
     }
     return -1;
   }
 
   static _newHashTable() {
     // Create a new JavaScript object to be used as a hash table. Use
@@ skipping 10 matching lines @@
 }
 
 class _IdentityHashMap<K, V> extends _HashMap<K, V> {
   int _computeHashCode(var key) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic keys like '__proto__'. Another option
     // would be to throw an exception if the hash code isn't a number.
     return JS('int', '# & 0x3ffffff', identityHashCode(key));
   }
 
-  int _findBucketIndex(var bucket, var key) {
+  int _findBucketIndex(var bucket, Object key) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i += 2) {
       if (identical(JS('var', '#[#]', bucket, i), key)) return i;
     }
     return -1;
   }
 }
 
 class _CustomHashMap<K, V> extends _HashMap<K, V> {
@@ skipping 23 matching lines @@
     return super._remove(key);
   }
 
   int _computeHashCode(var key) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic keys like '__proto__'. Another option
     // would be to throw an exception if the hash code isn't a number.
     return JS('int', '# & 0x3ffffff', _hashCode(key));
   }
 
-  int _findBucketIndex(var bucket, var key) {
+  int _findBucketIndex(var bucket, Object key) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i += 2) {
       if (_equals(JS('var', '#[#]', bucket, i), key)) return i;
     }
     return -1;
   }
 
   String toString() => Maps.mapToString(this);
 }
 
-class HashMapKeyIterable<E> extends IterableBase<E>
-                            implements EfficientLength {
-  final _map;
-  HashMapKeyIterable(this._map);
+class _HashMapKeyIterable<K, V> extends Iterable<K> implements EfficientLength {

[Leaf, 2016/05/18 20:11:53]

If you get rid of V in the iterator, I don't think you need it here either.

[sra1, 2016/05/18 22:10:04]

Done.

+  final _HashMap/*<K, V>*/ _map;
+  _HashMapKeyIterable(this._map);
 
   int get length => _map._length;
   bool get isEmpty => _map._length == 0;
 
-  Iterator<E> get iterator {
-    return new HashMapKeyIterator<E>(_map, _map._computeKeys());
+  Iterator<K> get iterator {
+    return new _HashMapKeyIterator<K, V>(_map, _map._computeKeys());
   }
 
   bool contains(Object element) {
     return _map.containsKey(element);
   }
 
-  void forEach(void f(E element)) {
-    List keys = _map._computeKeys();
+  void forEach(void f(K element)) {
+    List/*<K>*/ keys = _map._computeKeys();
     for (int i = 0, length = JS('int', '#.length', keys); i < length; i++) {
       f(JS('var', '#[#]', keys, i));
       if (JS('bool', '# !== #', keys, _map._keys)) {
         throw new ConcurrentModificationError(_map);
       }
     }
   }
 }
 
-class HashMapKeyIterator<E> implements Iterator<E> {
-  final _map;
-  final List _keys;
+class _HashMapKeyIterator<K, V> implements Iterator<K> {

[Leaf, 2016/05/18 20:11:53]

Why do you need V?  It never appears in the interface.  The only use is on the
type of _map, so you could just make that _HashMap<K, dynamic>.

[sra1, 2016/05/18 22:10:04]

Done.

+  final _HashMap/*<K, V>*/ _map;
+  final List/*<K>*/ _keys;
   int _offset = 0;
-  E _current;
+  K _current;
 
-  HashMapKeyIterator(this._map, this._keys);
+  _HashMapKeyIterator(this._map, this._keys);
 
-  E get current => _current;
+  K get current => _current;
 
   bool moveNext() {
     var keys = _keys;
     int offset = _offset;
     if (JS('bool', '# !== #', keys, _map._keys)) {
       throw new ConcurrentModificationError(_map);
     } else if (offset >= JS('int', '#.length', keys)) {
       _current = null;
       return false;
     } else {
@@ skipping 15 matching lines @@
                           bool isValidKey(Object potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
           return new JsLinkedHashMap<K, V>.es6();
         }
         hashCode = _defaultHashCode;
       } else {
         if (identical(identityHashCode, hashCode) &&
             identical(identical, equals)) {
-          return new _LinkedIdentityHashMap<K, V>();
+          return new _LinkedIdentityHashMap<K, V>.es6();
         }
         if (equals == null) {
           equals = _defaultEquals;
         }
       }
     } else {
       if (hashCode == null) {
         hashCode = _defaultHashCode;
       }
       if (equals == null) {
         equals = _defaultEquals;
       }
     }
     return new _LinkedCustomHashMap<K, V>(equals, hashCode, isValidKey);
   }
 
   @patch
-  factory LinkedHashMap.identity() = _LinkedIdentityHashMap<K, V>;
+  factory LinkedHashMap.identity() = _LinkedIdentityHashMap<K, V>.es6;
+}
 
-  // Private factory constructor called by generated code for map literals.
-  @NoInline()
-  factory LinkedHashMap._literal(List keyValuePairs) {
-    return fillLiteralMap(keyValuePairs, new _LinkedHashMap<K, V>());
+class _LinkedIdentityHashMap<K, V> extends JsLinkedHashMap<K, V> {
+  static bool get _supportsEs6Maps {
+    return true;
   }
 
-  // Private factory constructor called by generated code for map literals.
-  @NoThrows() @NoInline()
-  factory LinkedHashMap._empty() {
-    return new _LinkedHashMap<K, V>();
+  factory _LinkedIdentityHashMap.es6() {
+    return (_USE_ES6_MAPS && _LinkedIdentityHashMap._supportsEs6Maps)
+        ? new _Es6LinkedIdentityHashMap<K, V>()
+        : new _LinkedIdentityHashMap<K, V>();
+  }
+
+  _LinkedIdentityHashMap();
+
+  int internalComputeHashCode(var key) {
+    // We force the hash codes to be unsigned 30-bit integers to avoid
+    // issues with problematic keys like '__proto__'. Another option
+    // would be to throw an exception if the hash code isn't a number.
+    return JS('int', '# & 0x3ffffff', identityHashCode(key));
+  }
+
+  int internalFindBucketIndex(var bucket, var key) {
+    if (bucket == null) return -1;
+    int length = JS('int', '#.length', bucket);
+    for (int i = 0; i < length; i++) {
+      LinkedHashMapCell/*<K, V>*/ cell = JS('var', '#[#]', bucket, i);
+      if (identical(cell.hashMapCellKey, key)) return i;
+    }
+    return -1;
   }
 }
 
-class _LinkedHashMap<K, V> implements LinkedHashMap<K, V>, InternalMap {
-  int _length = 0;
-
-  // The hash map contents are divided into three parts: one part for
-  // string keys, one for numeric keys, and one for the rest. String
-  // and numeric keys map directly to their linked cells, but the rest
-  // of the entries are stored in bucket lists of the form:
-  //
-  //    [cell-0, cell-1, ...]
-  //
-  // where all keys in the same bucket share the same hash code.
-  var _strings;
-  var _nums;
-  var _rest;
-
-  // The keys and values are stored in cells that are linked together
-  // to form a double linked list.
-  LinkedHashMapCell _first;
-  LinkedHashMapCell _last;
-
-  // We track the number of modifications done to the key set of the
-  // hash map to be able to throw when the map is modified while being
-  // iterated over.
+class _Es6LinkedIdentityHashMap<K, V>
+    extends _LinkedIdentityHashMap<K, V> implements InternalMap {
+  final _map;
   int _modifications = 0;
 
-  _LinkedHashMap();
+  _Es6LinkedIdentityHashMap() : _map = JS('var', 'new Map()');
 
-
-  int get length => _length;
-  bool get isEmpty => _length == 0;
+  int get length => JS('int', '#.size', _map);
+  bool get isEmpty => length == 0;
   bool get isNotEmpty => !isEmpty;
 
-  Iterable<K> get keys {
-    return new LinkedHashMapKeyIterable<K>(this);
-  }
+  Iterable<K> get keys => new _Es6MapIterable<K>(this, true);
 
-  Iterable<V> get values {
-    return new MappedIterable<K, V>(keys, (each) => this[each]);
-  }
+  Iterable<V> get values =>
+      new _Es6MapIterable<V>(this, false);
 
   bool containsKey(Object key) {
-    if (_isStringKey(key)) {
-      var strings = _strings;
-      if (strings == null) return false;
-      LinkedHashMapCell cell = _getTableEntry(strings, key);
-      return cell != null;
-    } else if (_isNumericKey(key)) {
-      var nums = _nums;
-      if (nums == null) return false;
-      LinkedHashMapCell cell = _getTableEntry(nums, key);
-      return cell != null;
-    } else {
-      return _containsKey(key);
-    }
-  }
-
-  bool _containsKey(Object key) {
-    var rest = _rest;
-    if (rest == null) return false;
-    var bucket = _getBucket(rest, key);
-    return _findBucketIndex(bucket, key) >= 0;
+    return JS('bool', '#.has(#)', _map, key);
   }
 
   bool containsValue(Object value) {
-    return keys.any((each) => this[each] == value);
+    return values.any((each) => each == value);
   }
 
   void addAll(Map<K, V> other) {
     other.forEach((K key, V value) {
       this[key] = value;
     });
   }
 
   V operator[](Object key) {
-    if (_isStringKey(key)) {
-      var strings = _strings;
-      if (strings == null) return null;
-      LinkedHashMapCell cell = _getTableEntry(strings, key);
-      return (cell == null) ? null : cell._value;
-    } else if (_isNumericKey(key)) {
-      var nums = _nums;
-      if (nums == null) return null;
-      LinkedHashMapCell cell = _getTableEntry(nums, key);
-      return (cell == null) ? null : cell._value;
-    } else {
-      return _get(key);
-    }
-  }
-
-  V _get(Object key) {
-    var rest = _rest;
-    if (rest == null) return null;
-    var bucket = _getBucket(rest, key);
-    int index = _findBucketIndex(bucket, key);
-    if (index < 0) return null;
-    LinkedHashMapCell cell = JS('var', '#[#]', bucket, index);
-    return cell._value;
+    return JS('var', '#.get(#)', _map, key);
   }
 
   void operator[]=(K key, V value) {
-    if (_isStringKey(key)) {
-      var strings = _strings;
-      if (strings == null) _strings = strings = _newHashTable();
-      _addHashTableEntry(strings, key, value);
-    } else if (_isNumericKey(key)) {
-      var nums = _nums;
-      if (nums == null) _nums = nums = _newHashTable();
-      _addHashTableEntry(nums, key, value);
-    } else {
-      _set(key, value);
-    }
-  }
-
-  void _set(K key, V value) {
-    var rest = _rest;
-    if (rest == null) _rest = rest = _newHashTable();
-    var hash = _computeHashCode(key);
-    var bucket = JS('var', '#[#]', rest, hash);
-    if (bucket == null) {
-      LinkedHashMapCell cell = _newLinkedCell(key, value);
-      _setTableEntry(rest, hash, JS('var', '[#]', cell));
-    } else {
-      int index = _findBucketIndex(bucket, key);
-      if (index >= 0) {
-        LinkedHashMapCell cell = JS('var', '#[#]', bucket, index);
-        cell._value = value;
-      } else {
-        LinkedHashMapCell cell = _newLinkedCell(key, value);
-        JS('void', '#.push(#)', bucket, cell);
-      }
-    }
+    JS('var', '#.set(#, #)', _map, key, value);
+    _modified();
   }
 
   V putIfAbsent(K key, V ifAbsent()) {
     if (containsKey(key)) return this[key];
     V value = ifAbsent();
     this[key] = value;
     return value;
   }
 
   V remove(Object key) {
-    if (_isStringKey(key)) {
-      return _removeHashTableEntry(_strings, key);
-    } else if (_isNumericKey(key)) {
-      return _removeHashTableEntry(_nums, key);
-    } else {
-      return _remove(key);
+    V value = this[key];
+    JS('bool', '#.delete(#)', _map, key);
+    _modified();
+    return value;
+  }
+
+  void clear() {
+    JS('void', '#.clear()', _map);
+    _modified();
+  }
+
+  void forEach(void action(K key, V value)) {
+    var jsEntries = JS('var', '#.entries()', _map);
+    int modifications = _modifications;
+    while (true) {
+      var next = JS('var', '#.next()', jsEntries);
+      bool done = JS('bool', '#.done', next);
+      if (done) break;
+      var entry = JS('var', '#.value', next);
+      var key = JS('var', '#[0]', entry);
+      var value = JS('var', '#[1]', entry);
+      action(key, value);
+      if (modifications != _modifications) {
+        throw new ConcurrentModificationError(this);
+      }
     }
   }
 
-  V _remove(Object key) {
-    var rest = _rest;
-    if (rest == null) return null;
-    var bucket = _getBucket(rest, key);
-    int index = _findBucketIndex(bucket, key);
-    if (index < 0) return null;
-    // Use splice to remove the [cell] element at the index and
-    // unlink the cell before returning its value.
-    LinkedHashMapCell cell = JS('var', '#.splice(#, 1)[0]', bucket, index);
-    _unlinkCell(cell);
-    // TODO(kasperl): Consider getting rid of the bucket list when
-    // the length reaches zero.
-    return cell._value;
-  }
-
-  void clear() {
-    if (_length > 0) {
-      _strings = _nums = _rest = _first = _last = null;
-      _length = 0;
-      _modified();
-    }
-  }
-
-  void forEach(void action(K key, V value)) {
-    LinkedHashMapCell cell = _first;
-    int modifications = _modifications;
-    while (cell != null) {
-      action(cell._key, cell._value);
-      if (modifications != _modifications) {
-        throw new ConcurrentModificationError(this);
-      }
-      cell = cell._next;
-    }
-  }
-
-  void _addHashTableEntry(var table, K key, V value) {
-    LinkedHashMapCell cell = _getTableEntry(table, key);
-    if (cell == null) {
-      _setTableEntry(table, key, _newLinkedCell(key, value));
-    } else {
-      cell._value = value;
-    }
-  }
-
-  V _removeHashTableEntry(var table, Object key) {
-    if (table == null) return null;
-    LinkedHashMapCell cell = _getTableEntry(table, key);
-    if (cell == null) return null;
-    _unlinkCell(cell);
-    _deleteTableEntry(table, key);
-    return cell._value;
-  }
-
   void _modified() {
-    // Value cycles after 2^30 modifications. If you keep hold of an
-    // iterator for that long, you might miss a modification
-    // detection, and iteration can go sour. Don't do that.
+    // Value cycles after 2^30 modifications so that modification counts are
+    // always unboxed (Smi) values. Modification detection will be missed if you
+    // make exactly some multiple of 2^30 modifications between advances of an
+    // iterator.
     _modifications = (_modifications + 1) & 0x3ffffff;
   }
 
-  // Create a new cell and link it in as the last one in the list.
-  LinkedHashMapCell _newLinkedCell(K key, V value) {
-    LinkedHashMapCell cell = new LinkedHashMapCell(key, value);
-    if (_first == null) {
-      _first = _last = cell;
-    } else {
-      LinkedHashMapCell last = _last;
-      cell._previous = last;
-      _last = last._next = cell;
-    }
-    _length++;
-    _modified();
-    return cell;
-  }
-
-  // Unlink the given cell from the linked list of cells.
-  void _unlinkCell(LinkedHashMapCell cell) {
-    LinkedHashMapCell previous = cell._previous;
-    LinkedHashMapCell next = cell._next;
-    if (previous == null) {
-      assert(cell == _first);
-      _first = next;
-    } else {
-      previous._next = next;
-    }
-    if (next == null) {
-      assert(cell == _last);
-      _last = previous;
-    } else {
-      next._previous = previous;
-    }
-    _length--;
-    _modified();
-  }
-
-  static bool _isStringKey(var key) {
-    return key is String && key != '__proto__';
-  }
-
-  static bool _isNumericKey(var key) {
-    // Only treat unsigned 30-bit integers as numeric keys. This way,
-    // we avoid converting them to strings when we use them as keys in
-    // the JavaScript hash table object.
-    return key is num && JS('bool', '(# & 0x3ffffff) === #', key, key);
-  }
-
-  int _computeHashCode(var key) {
-    // We force the hash codes to be unsigned 30-bit integers to avoid
-    // issues with problematic keys like '__proto__'. Another option
-    // would be to throw an exception if the hash code isn't a number.
-    return JS('int', '# & 0x3ffffff', key.hashCode);
-  }
-
-  static _getTableEntry(var table, var key) {
-    return JS('var', '#[#]', table, key);
-  }
-
-  static void _setTableEntry(var table, var key, var value) {
-    assert(value != null);
-    JS('void', '#[#] = #', table, key, value);
-  }
-
-  static void _deleteTableEntry(var table, var key) {
-    JS('void', 'delete #[#]', table, key);
-  }
-
-  List _getBucket(var table, var key) {
-    var hash = _computeHashCode(key);
-    return JS('var', '#[#]', table, hash);
-  }
-
-  int _findBucketIndex(var bucket, var key) {
-    if (bucket == null) return -1;
-    int length = JS('int', '#.length', bucket);
-    for (int i = 0; i < length; i++) {
-      LinkedHashMapCell cell = JS('var', '#[#]', bucket, i);
-      if (cell._key == key) return i;
-    }
-    return -1;
-  }
-
-  static _newHashTable() {
-    // Create a new JavaScript object to be used as a hash table. Use
-    // Object.create to avoid the properties on Object.prototype
-    // showing up as entries.
-    var table = JS('var', 'Object.create(null)');
-    // Attempt to force the hash table into 'dictionary' mode by
-    // adding a property to it and deleting it again.
-    var temporaryKey = '<non-identifier-key>';
-    _setTableEntry(table, temporaryKey, table);
-    _deleteTableEntry(table, temporaryKey);
-    return table;
-  }
-
   String toString() => Maps.mapToString(this);
 }
 
-class _LinkedIdentityHashMap<K, V> extends _LinkedHashMap<K, V> {
-  int _computeHashCode(var key) {
-    // We force the hash codes to be unsigned 30-bit integers to avoid
-    // issues with problematic keys like '__proto__'. Another option
-    // would be to throw an exception if the hash code isn't a number.
-    return JS('int', '# & 0x3ffffff', identityHashCode(key));
-  }
+class _Es6MapIterable<E> extends Iterable<E>
+                         implements EfficientLength {
+  final _map;
+  final bool _isKeys;
 
-  int _findBucketIndex(var bucket, var key) {
-    if (bucket == null) return -1;
-    int length = JS('int', '#.length', bucket);
-    for (int i = 0; i < length; i++) {
-      LinkedHashMapCell cell = JS('var', '#[#]', bucket, i);
-      if (identical(cell._key, key)) return i;
+  _Es6MapIterable(this._map, this._isKeys);
+
+  int get length => _map.length;
+  bool get isEmpty => _map.isEmpty;
+
+  Iterator<E> get iterator =>
+      new _Es6MapIterator<E>(_map, _map._modifications, _isKeys);
+
+  bool contains(Object element) => _map.containsKey(element);
+
+  void forEach(void f(E element)) {
+    var jsIterator;
+    if (_isKeys) {
+      jsIterator = JS('var', '#.keys()', _map._map);
+    } else {
+      jsIterator = JS('var', '#.values()', _map._map);
     }
-    return -1;
+    int modifications = _map._modifications;
+    while (true) {
+      var next = JS('var', '#.next()', jsIterator);
+      bool done = JS('bool', '#.done', next);
+      if (done) break;
+      var value = JS('var', '#.value', next);
+      f(value);
+      if (modifications != _map._modifications) {
+        throw new ConcurrentModificationError(_map);
+      }
+    }
   }
 }
 
-class _LinkedCustomHashMap<K, V> extends _LinkedHashMap<K, V> {
+class _Es6MapIterator<E> implements Iterator<E> {
+  final _map;
+  final int _modifications;
+  final bool _isKeys;
+  var _jsIterator;
+  var _next;
+  E _current;
+  bool _done;
+
+  _Es6MapIterator(this._map, this._modifications, this._isKeys) {
+    if (_isKeys) {
+      _jsIterator = JS('var', '#.keys()', _map._map);
+    } else {
+      _jsIterator = JS('var', '#.values()', _map._map);
+    }
+    _done = false;
+  }
+
+  E get current => _current;
+
+  bool moveNext() {
+    if (_modifications != _map._modifications) {
+      throw new ConcurrentModificationError(_map);
+    }
+    if (_done) return false;
+    _next = JS('var', '#.next()', _jsIterator);
+    bool done = JS('bool', '#.done', _next);
+    if (done) {
+      _current = null;
+      _done = true;
+      return false;
+    } else {
+      _current = JS('var', '#.value', _next);
+      return true;
+    }
+  }
+}
+
+// TODO(floitsch): use ES6 maps when available.
+class _LinkedCustomHashMap<K, V> extends JsLinkedHashMap<K, V> {
   final _Equality<K> _equals;
   final _Hasher<K> _hashCode;
   final _Predicate<Object> _validKey;
   _LinkedCustomHashMap(this._equals, this._hashCode,
                        bool validKey(Object potentialKey))
       : _validKey = (validKey != null) ? validKey : ((v) => v is K);
 
   V operator[](Object key) {
     if (!_validKey(key)) return null;
-    return super._get(key);
+    return super.internalGet(key);
   }
 
   void operator[]=(K key, V value) {
-    super._set(key, value);
+    super.internalSet(key, value);
   }
 
   bool containsKey(Object key) {
     if (!_validKey(key)) return false;
-    return super._containsKey(key);
+    return super.internalContainsKey(key);
   }
 
   V remove(Object key) {
     if (!_validKey(key)) return null;
-    return super._remove(key);
+    return super.internalRemove(key);
   }
 
-  int _computeHashCode(var key) {
+  int internalComputeHashCode(var key) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic keys like '__proto__'. Another option
     // would be to throw an exception if the hash code isn't a number.
     return JS('int', '# & 0x3ffffff', _hashCode(key));
   }
 
-  int _findBucketIndex(var bucket, var key) {
+  int internalFindBucketIndex(var bucket, var key) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
-      LinkedHashMapCell cell = JS('var', '#[#]', bucket, i);
-      if (_equals(cell._key, key)) return i;
+      LinkedHashMapCell/*<K, V>*/ cell = JS('var', '#[#]', bucket, i);
+      if (_equals(cell.hashMapCellKey, key)) return i;
     }
     return -1;
   }
 }
 
-class LinkedHashMapCell {
-  final _key;
-  var _value;
-
-  LinkedHashMapCell _next;
-  LinkedHashMapCell _previous;
-
-  LinkedHashMapCell(this._key, this._value);
-}
-
-class LinkedHashMapKeyIterable<E> extends IterableBase<E>
-                                  implements EfficientLength {
-  final _map;
-  LinkedHashMapKeyIterable(this._map);
-
-  int get length => _map._length;
-  bool get isEmpty => _map._length == 0;
-
-  Iterator<E> get iterator {
-    return new LinkedHashMapKeyIterator<E>(_map, _map._modifications);
-  }
-
-  bool contains(Object element) {
-    return _map.containsKey(element);
-  }
-
-  void forEach(void f(E element)) {
-    LinkedHashMapCell cell = _map._first;
-    int modifications = _map._modifications;
-    while (cell != null) {
-      f(cell._key);
-      if (modifications != _map._modifications) {
-        throw new ConcurrentModificationError(_map);
-      }
-      cell = cell._next;
-    }
-  }
-}
-
-class LinkedHashMapKeyIterator<E> implements Iterator<E> {
-  final _map;
-  final int _modifications;
-  LinkedHashMapCell _cell;
-  E _current;
-
-  LinkedHashMapKeyIterator(this._map, this._modifications) {
-    _cell = _map._first;
-  }
-
-  E get current => _current;
-
-  bool moveNext() {
-    if (_modifications != _map._modifications) {
-      throw new ConcurrentModificationError(_map);
-    } else if (_cell == null) {
-      _current = null;
-      return false;
-    } else {
-      _current = _cell._key;
-      _cell = _cell._next;
-      return true;
-    }
-  }
-}
-
 @patch
 class HashSet<E> {
   @patch
   factory HashSet({ bool equals(E e1, E e2),
                     int hashCode(E e),
                     bool isValidKey(Object potentialKey) }) {
     if (isValidKey == null) {
       if (hashCode == null) {
         if (equals == null) {
           return new _HashSet<E>();
@@ skipping 34 matching lines @@
   //
   //    [element-0, element-1, element-2, ...]
   //
   // where all elements in the same bucket share the same hash code.
   var _strings;
   var _nums;
   var _rest;
 
   // When iterating over the hash set, it is very convenient to have a
   // list of all the elements. We cache that on the instance and clear
-  // the the cache whenever the set changes. This is also used to
+  // the cache whenever the set changes. This is also used to
   // guard against concurrent modifications.
-  List _elements;
+  List/*<E>*/ _elements;
 
   _HashSet();
 
   Set<E> _newSet() => new _HashSet<E>();
 
   // Iterable.
   Iterator<E> get iterator {
-    return new HashSetIterator<E>(this, _computeElements());
+    return new _HashSetIterator<E>(this, _computeElements());
   }
 
   int get length => _length;
   bool get isEmpty => _length == 0;
   bool get isNotEmpty => !isEmpty;
 
   bool contains(Object object) {
     if (_isStringElement(object)) {
       var strings = _strings;
       return (strings == null) ? false : _hasTableEntry(strings, object);
@@ skipping 92 matching lines @@
     return true;
   }
 
   void clear() {
     if (_length > 0) {
       _strings = _nums = _rest = _elements = null;
       _length = 0;
     }
   }
 
-  List _computeElements() {
+  List/*<E>*/ _computeElements() {
     if (_elements != null) return _elements;
-    List result = new List(_length);
+    List/*<E>*/ result = new List/*<E>*/(_length);
     int index = 0;
 
     // Add all string elements to the list.
     var strings = _strings;
     if (strings != null) {
       var names = JS('var', 'Object.getOwnPropertyNames(#)', strings);
       int entries = JS('int', '#.length', names);
       for (int i = 0; i < entries; i++) {
         String element = JS('String', '#[#]', names, i);
         JS('void', '#[#] = #', result, index, element);
@@ skipping 83 matching lines @@
 
   static void _setTableEntry(var table, var key, var value) {
     assert(value != null);
     JS('void', '#[#] = #', table, key, value);
   }
 
   static void _deleteTableEntry(var table, var key) {
     JS('void', 'delete #[#]', table, key);
   }
 
-  List _getBucket(var table, var element) {
+  List/*<E>*/ _getBucket(var table, var element) {
     var hash = _computeHashCode(element);
     return JS('var', '#[#]', table, hash);
   }
 
   int _findBucketIndex(var bucket, var element) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
       if (JS('var', '#[#]', bucket, i) == element) return i;
     }
@@ skipping 72 matching lines @@
     if (!_validKey(object)) return null;
     return super._lookup(object);
   }
 
   bool remove(Object object) {
     if (!_validKey(object)) return false;
     return super._remove(object);
   }
 }
 
-// TODO(kasperl): Share this code with HashMapKeyIterator<E>?
-class HashSetIterator<E> implements Iterator<E> {
+// TODO(kasperl): Share this code with _HashMapKeyIterator<E>?
+class _HashSetIterator<E> implements Iterator<E> {
   final _set;
-  final List _elements;
+  final List/*<E>*/ _elements;
   int _offset = 0;
   E _current;
 
-  HashSetIterator(this._set, this._elements);
+  _HashSetIterator(this._set, this._elements);
 
   E get current => _current;
 
   bool moveNext() {
     var elements = _elements;
     int offset = _offset;
     if (JS('bool', '# !== #', elements, _set._elements)) {
       throw new ConcurrentModificationError(_set);
     } else if (offset >= JS('int', '#.length', elements)) {
       _current = null;
@@ skipping 56 matching lines @@
   //
   //    [cell-0, cell-1, ...]
   //
   // where all elements in the same bucket share the same hash code.
   var _strings;
   var _nums;
   var _rest;
 
   // The elements are stored in cells that are linked together
   // to form a double linked list.
-  LinkedHashSetCell _first;
-  LinkedHashSetCell _last;
+  _LinkedHashSetCell/*<E>*/ _first;
+  _LinkedHashSetCell/*<E>*/ _last;
 
   // We track the number of modifications done to the element set to
   // be able to throw when the set is modified while being iterated
   // over.
   int _modifications = 0;
 
   _LinkedHashSet();
 
   Set<E> _newSet() => new _LinkedHashSet<E>();
 
   void _unsupported(String operation) {
     throw 'LinkedHashSet: unsupported $operation';
   }
 
   // Iterable.
   Iterator<E> get iterator {
-    return new LinkedHashSetIterator(this, _modifications);
+    return new _LinkedHashSetIterator(this, _modifications);
   }
 
   int get length => _length;
   bool get isEmpty => _length == 0;
   bool get isNotEmpty => !isEmpty;
 
   bool contains(Object object) {
     if (_isStringElement(object)) {
       var strings = _strings;
       if (strings == null) return false;
-      LinkedHashSetCell cell = _getTableEntry(strings, object);
+      _LinkedHashSetCell/*<E>*/ cell = _getTableEntry(strings, object);
       return cell != null;
     } else if (_isNumericElement(object)) {
       var nums = _nums;
       if (nums == null) return false;
-      LinkedHashSetCell cell = _getTableEntry(nums, object);
+      _LinkedHashSetCell/*<E>*/ cell = _getTableEntry(nums, object);
       return cell != null;
     } else {
       return _contains(object);
     }
   }
 
   bool _contains(Object object) {
     var rest = _rest;
     if (rest == null) return false;
     var bucket = _getBucket(rest, object);
@@ skipping 11 matching lines @@
   E _lookup(Object object) {
     var rest = _rest;
     if (rest == null) return null;
     var bucket = _getBucket(rest, object);
     var index = _findBucketIndex(bucket, object);
     if (index < 0) return null;
     return bucket[index]._element;
   }
 
   void forEach(void action(E element)) {
-    LinkedHashSetCell cell = _first;
+    _LinkedHashSetCell/*<E>*/ cell = _first;
     int modifications = _modifications;
     while (cell != null) {
       action(cell._element);
       if (modifications != _modifications) {
         throw new ConcurrentModificationError(this);
       }
       cell = cell._next;
     }
   }
 
@@ skipping 21 matching lines @@
       return _add(element);
     }
   }
 
   bool _add(E element) {
     var rest = _rest;
     if (rest == null) _rest = rest = _newHashTable();
     var hash = _computeHashCode(element);
     var bucket = JS('var', '#[#]', rest, hash);
     if (bucket == null) {
-      LinkedHashSetCell cell = _newLinkedCell(element);
+      _LinkedHashSetCell/*<E>*/ cell = _newLinkedCell(element);
       _setTableEntry(rest, hash, JS('var', '[#]', cell));
     } else {
       int index = _findBucketIndex(bucket, element);
       if (index >= 0) return false;
-      LinkedHashSetCell cell = _newLinkedCell(element);
+      _LinkedHashSetCell/*<E>*/ cell = _newLinkedCell(element);
       JS('void', '#.push(#)', bucket, cell);
     }
     return true;
   }
 
   bool remove(Object object) {
     if (_isStringElement(object)) {
       return _removeHashTableEntry(_strings, object);
     } else if (_isNumericElement(object)) {
       return _removeHashTableEntry(_nums, object);
     } else {
       return _remove(object);
     }
   }
 
   bool _remove(Object object) {
     var rest = _rest;
     if (rest == null) return false;
     var bucket = _getBucket(rest, object);
     int index = _findBucketIndex(bucket, object);
     if (index < 0) return false;
     // Use splice to remove the [cell] element at the index and
     // unlink it.
-    LinkedHashSetCell cell = JS('var', '#.splice(#, 1)[0]', bucket, index);
+    _LinkedHashSetCell/*<E>*/ cell = JS('var', '#.splice(#, 1)[0]', bucket, index);
     _unlinkCell(cell);
     return true;
   }
 
   void removeWhere(bool test(E element)) {
     _filterWhere(test, true);
   }
 
   void retainWhere(bool test(E element)) {
     _filterWhere(test, false);
   }
 
   void _filterWhere(bool test(E element), bool removeMatching) {
-    LinkedHashSetCell cell = _first;
+    _LinkedHashSetCell/*<E>*/ cell = _first;
     while (cell != null) {
       E element = cell._element;
-      LinkedHashSetCell next = cell._next;
+      _LinkedHashSetCell/*<E>*/ next = cell._next;
       int modifications = _modifications;
       bool shouldRemove = (removeMatching == test(element));
       if (modifications != _modifications) {
         throw new ConcurrentModificationError(this);
       }
       if (shouldRemove) remove(element);
       cell = next;
     }
   }
 
   void clear() {
     if (_length > 0) {
       _strings = _nums = _rest = _first = _last = null;
       _length = 0;
       _modified();
     }
   }
 
   bool _addHashTableEntry(var table, E element) {
-    LinkedHashSetCell cell = _getTableEntry(table, element);
+    _LinkedHashSetCell/*<E>*/ cell = _getTableEntry(table, element);
     if (cell != null) return false;
     _setTableEntry(table, element, _newLinkedCell(element));
     return true;
   }
 
   bool _removeHashTableEntry(var table, Object element) {
     if (table == null) return false;
-    LinkedHashSetCell cell = _getTableEntry(table, element);
+    _LinkedHashSetCell/*<E>*/ cell = _getTableEntry(table, element);
     if (cell == null) return false;
     _unlinkCell(cell);
     _deleteTableEntry(table, element);
     return true;
   }
 
   void _modified() {
     // Value cycles after 2^30 modifications. If you keep hold of an
     // iterator for that long, you might miss a modification
     // detection, and iteration can go sour. Don't do that.
     _modifications = (_modifications + 1) & 0x3ffffff;
   }
 
   // Create a new cell and link it in as the last one in the list.
-  LinkedHashSetCell _newLinkedCell(E element) {
-    LinkedHashSetCell cell = new LinkedHashSetCell(element);
+  _LinkedHashSetCell/*<E>*/ _newLinkedCell(E element) {
+    _LinkedHashSetCell/*<E>*/ cell = new _LinkedHashSetCell/*<E>*/(element);
     if (_first == null) {
       _first = _last = cell;
     } else {
-      LinkedHashSetCell last = _last;
+      _LinkedHashSetCell/*<E>*/ last = _last;
       cell._previous = last;
       _last = last._next = cell;
     }
     _length++;
     _modified();
     return cell;
   }
 
   // Unlink the given cell from the linked list of cells.
-  void _unlinkCell(LinkedHashSetCell cell) {
-    LinkedHashSetCell previous = cell._previous;
-    LinkedHashSetCell next = cell._next;
+  void _unlinkCell(_LinkedHashSetCell/*<E>*/ cell) {
+    _LinkedHashSetCell/*<E>*/ previous = cell._previous;
+    _LinkedHashSetCell/*<E>*/ next = cell._next;
     if (previous == null) {
       assert(cell == _first);
       _first = next;
     } else {
       previous._next = next;
     }
     if (next == null) {
       assert(cell == _last);
       _last = previous;
     } else {
@@ skipping 16 matching lines @@
   }
 
   int _computeHashCode(var element) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic elements like '__proto__'. Another
     // option would be to throw an exception if the hash code isn't a
     // number.
     return JS('int', '# & 0x3ffffff', element.hashCode);
   }
 
-  static _getTableEntry(var table, var key) {
+  _LinkedHashSetCell/*<E>*/ _getTableEntry(var table, var key) {
     return JS('var', '#[#]', table, key);
   }
 
   static void _setTableEntry(var table, var key, var value) {
     assert(value != null);
     JS('void', '#[#] = #', table, key, value);
   }
 
   static void _deleteTableEntry(var table, var key) {
     JS('void', 'delete #[#]', table, key);
   }
 
-  List _getBucket(var table, var element) {
+  List/*<_LinkedHashSetCell<E>>*/ _getBucket(var table, var element) {
     var hash = _computeHashCode(element);
     return JS('var', '#[#]', table, hash);
   }
 
   int _findBucketIndex(var bucket, var element) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
-      LinkedHashSetCell cell = JS('var', '#[#]', bucket, i);
+      _LinkedHashSetCell/*<E>*/ cell = JS('var', '#[#]', bucket, i);
       if (cell._element == element) return i;
     }
     return -1;
   }
 
   static _newHashTable() {
     // Create a new JavaScript object to be used as a hash table. Use
     // Object.create to avoid the properties on Object.prototype
     // showing up as entries.
     var table = JS('var', 'Object.create(null)');
@@ skipping 13 matching lines @@
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic keys like '__proto__'. Another option
     // would be to throw an exception if the hash code isn't a number.
     return JS('int', '# & 0x3ffffff', identityHashCode(key));
   }
 
   int _findBucketIndex(var bucket, var element) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
-      LinkedHashSetCell cell = JS('var', '#[#]', bucket, i);
+      _LinkedHashSetCell/*<E>*/ cell = JS('var', '#[#]', bucket, i);
       if (identical(cell._element, element)) return i;
     }
     return -1;
   }
 }
 
 class _LinkedCustomHashSet<E> extends _LinkedHashSet<E> {
   _Equality<E> _equality;
   _Hasher<E> _hasher;
   _Predicate<Object> _validKey;
   _LinkedCustomHashSet(this._equality, this._hasher,
                        bool validKey(Object potentialKey))
       : _validKey = (validKey != null) ? validKey : ((x) => x is E);
 
   Set<E> _newSet() =>
       new _LinkedCustomHashSet<E>(_equality, _hasher, _validKey);
 
   int _findBucketIndex(var bucket, var element) {
     if (bucket == null) return -1;
     int length = JS('int', '#.length', bucket);
     for (int i = 0; i < length; i++) {
-      LinkedHashSetCell cell = JS('var', '#[#]', bucket, i);
+      _LinkedHashSetCell/*<E>*/ cell = JS('var', '#[#]', bucket, i);
       if (_equality(cell._element, element)) return i;
     }
     return -1;
   }
 
   int _computeHashCode(var element) {
     // We force the hash codes to be unsigned 30-bit integers to avoid
     // issues with problematic elements like '__proto__'. Another
     // option would be to throw an exception if the hash code isn't a
     // number.
@@ skipping 26 matching lines @@
 
   void removeAll(Iterable<Object> elements) {
     for (Object element in elements) {
       if (_validKey(element)) {
         super._remove(element);
       }
     }
   }
 }
 
-class LinkedHashSetCell {
-  final _element;
+class _LinkedHashSetCell<E> {
+  E _element;
 
-  LinkedHashSetCell _next;
-  LinkedHashSetCell _previous;
+  _LinkedHashSetCell<E> _next;
+  _LinkedHashSetCell<E> _previous;
 
-  LinkedHashSetCell(this._element);
+  _LinkedHashSetCell(this._element);
 }
 
 // TODO(kasperl): Share this code with LinkedHashMapKeyIterator<E>?
-class LinkedHashSetIterator<E> implements Iterator<E> {
+class _LinkedHashSetIterator<E> implements Iterator<E> {
   final _set;
   final int _modifications;
-  LinkedHashSetCell _cell;
+  _LinkedHashSetCell _cell;
   E _current;
 
-  LinkedHashSetIterator(this._set, this._modifications) {
+  _LinkedHashSetIterator(this._set, this._modifications) {
     _cell = _set._first;
   }
 
   E get current => _current;
 
   bool moveNext() {
     if (_modifications != _set._modifications) {
       throw new ConcurrentModificationError(_set);
     } else if (_cell == null) {
       _current = null;
       return false;
     } else {
       _current = _cell._element;
       _cell = _cell._next;
       return true;
     }
   }
 }