Modernize the package's style.

lib/wrappers.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.
 
-/**
- * Delegating wrappers for [Iterable], [List], [Set], [Queue] and [Map].
- *
- * Also adds unmodifiable views for `Set` and `Map`, and a fixed length
- * view for `List`. The unmodifiable list view from `dart:collection` is
- * exported as well, just for completeness.
- */
+/// Import `collection.dart` instead.
+@Deprecated("Will be removed in collection 2.0.0.")
 library dart.pkg.collection.wrappers;
 
-import "dart:collection";
-import "dart:math" show Random;
-
-import "src/unmodifiable_wrappers.dart";
-
 export "src/canonicalized_map.dart";
 export "src/unmodifiable_wrappers.dart";
+export "src/wrappers.dart";
 
-/**
- * A base class for delegating iterables.
- *
- * Subclasses can provide a [_base] that should be delegated to. Unlike
- * [DelegatingIterable], this allows the base to be created on demand.
- */
-abstract class _DelegatingIterableBase<E> implements Iterable<E> {
-  Iterable<E> get _base;
-
-  const _DelegatingIterableBase();
-
-  bool any(bool test(E element)) => _base.any(test);
-
-  bool contains(Object element) => _base.contains(element);
-
-  E elementAt(int index) => _base.elementAt(index);
-
-  bool every(bool test(E element)) => _base.every(test);
-
-  Iterable expand(Iterable f(E element)) => _base.expand(f);
-
-  E get first => _base.first;
-
-  E firstWhere(bool test(E element), {E orElse()}) =>
-      _base.firstWhere(test, orElse: orElse);
-
-  fold(initialValue, combine(previousValue, E element)) =>
-      _base.fold(initialValue, combine);
-
-  void forEach(void f(E element)) => _base.forEach(f);
-
-  bool get isEmpty => _base.isEmpty;
-
-  bool get isNotEmpty => _base.isNotEmpty;
-
-  Iterator<E> get iterator => _base.iterator;
-
-  String join([String separator = ""]) => _base.join(separator);
-
-  E get last => _base.last;
-
-  E lastWhere(bool test(E element), {E orElse()}) =>
-      _base.lastWhere(test, orElse: orElse);
-
-  int get length => _base.length;
-
-  Iterable map(f(E element)) => _base.map(f);
-
-  E reduce(E combine(E value, E element)) => _base.reduce(combine);
-
-  E get single => _base.single;
-
-  E singleWhere(bool test(E element)) => _base.singleWhere(test);
-
-  Iterable<E> skip(int n) => _base.skip(n);
-
-  Iterable<E> skipWhile(bool test(E value)) => _base.skipWhile(test);
-
-  Iterable<E> take(int n) => _base.take(n);
-
-  Iterable<E> takeWhile(bool test(E value)) => _base.takeWhile(test);
-
-  List<E> toList({bool growable: true}) => _base.toList(growable: growable);
-
-  Set<E> toSet() => _base.toSet();
-
-  Iterable<E> where(bool test(E element)) => _base.where(test);
-
-  String toString() => _base.toString();
-}
-
-/**
- * Creates an [Iterable] that delegates all operations to a base iterable.
- *
- * This class can be used hide non-`Iterable` methods of an iterable object,
- * or it can be extended to add extra functionality on top of an existing
- * iterable object.
- */
-class DelegatingIterable<E> extends _DelegatingIterableBase<E> {
-  final Iterable<E> _base;
-
-  /**
-   * Create a wrapper that forwards operations to [base].
-   */
-  const DelegatingIterable(Iterable<E> base) : _base = base;
-}
-
-
-/**
- * Creates a [List] that delegates all operations to a base list.
- *
- * This class can be used hide non-`List` methods of a list object,
- * or it can be extended to add extra functionality on top of an existing
- * list object.
- */
-class DelegatingList<E> extends DelegatingIterable<E> implements List<E> {
-  const DelegatingList(List<E> base) : super(base);
-
-  List<E> get _listBase => _base;
-
-  E operator [](int index) => _listBase[index];
-
-  void operator []=(int index, E value) {
-    _listBase[index] = value;
-  }
-
-  void add(E value) {
-    _listBase.add(value);
-  }
-
-  void addAll(Iterable<E> iterable) {
-    _listBase.addAll(iterable);
-  }
-
-  Map<int, E> asMap() => _listBase.asMap();
-
-  void clear() {
-    _listBase.clear();
-  }
-
-  void fillRange(int start, int end, [E fillValue]) {
-    _listBase.fillRange(start, end, fillValue);
-  }
-
-  Iterable<E> getRange(int start, int end) => _listBase.getRange(start, end);
-
-  int indexOf(E element, [int start = 0]) => _listBase.indexOf(element, start);
-
-  void insert(int index, E element) {
-    _listBase.insert(index, element);
-  }
-
-  void insertAll(int index, Iterable<E> iterable) {
-    _listBase.insertAll(index, iterable);
-  }
-
-  int lastIndexOf(E element, [int start]) =>
-      _listBase.lastIndexOf(element, start);
-
-  void set length(int newLength) {
-    _listBase.length = newLength;
-  }
-
-  bool remove(Object value) => _listBase.remove(value);
-
-  E removeAt(int index) => _listBase.removeAt(index);
-
-  E removeLast() => _listBase.removeLast();
-
-  void removeRange(int start, int end) {
-    _listBase.removeRange(start, end);
-  }
-
-  void removeWhere(bool test(E element)) {
-    _listBase.removeWhere(test);
-  }
-
-  void replaceRange(int start, int end, Iterable<E> iterable) {
-    _listBase.replaceRange(start, end, iterable);
-  }
-
-  void retainWhere(bool test(E element)) {
-    _listBase.retainWhere(test);
-  }
-
-  Iterable<E> get reversed => _listBase.reversed;
-
-  void setAll(int index, Iterable<E> iterable) {
-    _listBase.setAll(index, iterable);
-  }
-
-  void setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) {
-    _listBase.setRange(start, end, iterable, skipCount);
-  }
-
-  void shuffle([Random random]) {
-    _listBase.shuffle(random);
-  }
-
-  void sort([int compare(E a, E b)]) {
-    _listBase.sort(compare);
-  }
-
-  List<E> sublist(int start, [int end]) => _listBase.sublist(start, end);
-}
-
-
-/**
- * Creates a [Set] that delegates all operations to a base set.
- *
- * This class can be used hide non-`Set` methods of a set object,
- * or it can be extended to add extra functionality on top of an existing
- * set object.
- */
-class DelegatingSet<E> extends DelegatingIterable<E> implements Set<E> {
-  const DelegatingSet(Set<E> base) : super(base);
-
-  Set<E> get _setBase => _base;
-
-  bool add(E value) => _setBase.add(value);
-
-  void addAll(Iterable<E> elements) {
-    _setBase.addAll(elements);
-  }
-
-  void clear() {
-    _setBase.clear();
-  }
-
-  bool containsAll(Iterable<Object> other) => _setBase.containsAll(other);
-
-  Set<E> difference(Set<E> other) => _setBase.difference(other);
-
-  Set<E> intersection(Set<Object> other) => _setBase.intersection(other);
-
-  E lookup(Object element) => _setBase.lookup(element);
-
-  bool remove(Object value) => _setBase.remove(value);
-
-  void removeAll(Iterable<Object> elements) {
-    _setBase.removeAll(elements);
-  }
-
-  void removeWhere(bool test(E element)) {
-    _setBase.removeWhere(test);
-  }
-
-  void retainAll(Iterable<Object> elements) {
-    _setBase.retainAll(elements);
-  }
-
-  void retainWhere(bool test(E element)) {
-    _setBase.retainWhere(test);
-  }
-
-  Set<E> union(Set<E> other) => _setBase.union(other);
-
-  Set<E> toSet() => new DelegatingSet<E>(_setBase.toSet());
-}
-
-/**
- * Creates a [Queue] that delegates all operations to a base queue.
- *
- * This class can be used hide non-`Queue` methods of a queue object,
- * or it can be extended to add extra functionality on top of an existing
- * queue object.
- */
-class DelegatingQueue<E> extends DelegatingIterable<E> implements Queue<E> {
-  const DelegatingQueue(Queue<E> queue) : super(queue);
-
-  Queue<E> get _baseQueue => _base;
-
-  void add(E value) {
-    _baseQueue.add(value);
-  }
-
-  void addAll(Iterable<E> iterable) {
-    _baseQueue.addAll(iterable);
-  }
-
-  void addFirst(E value) {
-    _baseQueue.addFirst(value);
-  }
-
-  void addLast(E value) {
-    _baseQueue.addLast(value);
-  }
-
-  void clear() {
-    _baseQueue.clear();
-  }
-
-  bool remove(Object object) => _baseQueue.remove(object);
-
-  void removeWhere(bool test(E element)) { _baseQueue.removeWhere(test); }
-
-  void retainWhere(bool test(E element)) { _baseQueue.retainWhere(test); }
-
-  E removeFirst() => _baseQueue.removeFirst();
-
-  E removeLast() => _baseQueue.removeLast();
-}
-
-/**
- * Creates a [Map] that delegates all operations to a base map.
- *
- * This class can be used hide non-`Map` methods of an object that extends
- * `Map`, or it can be extended to add extra functionality on top of an existing
- * map object.
- */
-class DelegatingMap<K, V> implements Map<K, V> {
-  final Map<K, V> _base;
-
-  const DelegatingMap(Map<K, V> base) : _base = base;
-
-  V operator [](Object key) => _base[key];
-
-  void operator []=(K key, V value) {
-    _base[key] = value;
-  }
-
-  void addAll(Map<K, V> other) {
-    _base.addAll(other);
-  }
-
-  void clear() {
-    _base.clear();
-  }
-
-  bool containsKey(Object key) => _base.containsKey(key);
-
-  bool containsValue(Object value) => _base.containsValue(value);
-
-  void forEach(void f(K key, V value)) {
-    _base.forEach(f);
-  }
-
-  bool get isEmpty => _base.isEmpty;
-
-  bool get isNotEmpty => _base.isNotEmpty;
-
-  Iterable<K> get keys => _base.keys;
-
-  int get length => _base.length;
-
-  V putIfAbsent(K key, V ifAbsent()) => _base.putIfAbsent(key, ifAbsent);
-
-  V remove(Object key) => _base.remove(key);
-
-  Iterable<V> get values => _base.values;
-
-  String toString() => _base.toString();
-}
-
-/**
- * An unmodifiable [Set] view of the keys of a [Map].
- *
- * The set delegates all operations to the underlying map.
- *
- * A `Map` can only contain each key once, so its keys can always
- * be viewed as a `Set` without any loss, even if the [Map.keys]
- * getter only shows an [Iterable] view of the keys.
- *
- * Note that [lookup] is not supported for this set.
- */
-class MapKeySet<E> extends _DelegatingIterableBase<E>
-    with UnmodifiableSetMixin<E> {
-  final Map<E, dynamic> _baseMap;
-
-  MapKeySet(Map<E, dynamic> base) : _baseMap = base;
-
-  Iterable<E> get _base => _baseMap.keys;
-
-  bool contains(Object element) => _baseMap.containsKey(element);
-
-  bool get isEmpty => _baseMap.isEmpty;
-
-  bool get isNotEmpty => _baseMap.isNotEmpty;
-
-  int get length => _baseMap.length;
-
-  String toString() => "{${_base.join(', ')}}";
-
-  bool containsAll(Iterable<Object> other) => other.every(contains);
-
-  /**
-   * Returns a new set with the the elements of [this] that are not in [other].
-   *
-   * That is, the returned set contains all the elements of this [Set] that are
-   * not elements of [other] according to `other.contains`.
-   *
-   * Note that the returned set will use the default equality operation, which
-   * may be different than the equality operation [this] uses.
-   */
-  Set<E> difference(Set<E> other) =>
-      where((element) => !other.contains(element)).toSet();
-
-  /**
-   * Returns a new set which is the intersection between [this] and [other].
-   *
-   * That is, the returned set contains all the elements of this [Set] that are
-   * also elements of [other] according to `other.contains`.
-   *
-   * Note that the returned set will use the default equality operation, which
-   * may be different than the equality operation [this] uses.
-   */
-  Set<E> intersection(Set<Object> other) => where(other.contains).toSet();
-
-  /**
-   * Throws an [UnsupportedError] since there's no corresponding method for
-   * [Map]s.
-   */
-  E lookup(E element) => throw new UnsupportedError(
-      "MapKeySet doesn't support lookup().");
-
-  /**
-   * Returns a new set which contains all the elements of [this] and [other].
-   *
-   * That is, the returned set contains all the elements of this [Set] and all
-   * the elements of [other].
-   *
-   * Note that the returned set will use the default equality operation, which
-   * may be different than the equality operation [this] uses.
-   */
-  Set<E> union(Set<E> other) => toSet()..addAll(other);
-}
-
-/**
- * Creates a modifiable [Set] view of the values of a [Map].
- * 
- * The `Set` view assumes that the keys of the `Map` can be uniquely determined
- * from the values. The `keyForValue` function passed to the constructor finds
- * the key for a single value. The `keyForValue` function should be consistent
- * with equality. If `value1 == value2` then `keyForValue(value1)` and
- * `keyForValue(value2)` should be considered equal keys by the underlying map,
- * and vice versa.
- *
- * Modifying the set will modify the underlying map based on the key returned by
- * `keyForValue`.
- *
- * If the `Map` contents are not compatible with the `keyForValue` function, the
- * set will not work consistently, and may give meaningless responses or do
- * inconsistent updates.
- *
- * This set can, for example, be used on a map from database record IDs to the
- * records. It exposes the records as a set, and allows for writing both
- * `recordSet.add(databaseRecord)` and `recordMap[id]`.
- *
- * Effectively, the map will act as a kind of index for the set.
- */
-class MapValueSet<K, V> extends _DelegatingIterableBase<V> implements Set<V> {
-  final Map<K, V> _baseMap;
-  final Function _keyForValue;
-
-  /**
-   * Creates a new [MapValueSet] based on [base].
-   *
-   * [keyForValue] returns the key in the map that should be associated with the
-   * given value. The set's notion of equality is identical to the equality of
-   * the return values of [keyForValue].
-   */
-  MapValueSet(Map<K, V> base, K keyForValue(V value))
-      : _baseMap = base,
-        _keyForValue = keyForValue;
-
-  Iterable<V> get _base => _baseMap.values;
-
-  bool contains(Object element) {
-    if (element != null && element is! V) return false;
-    return _baseMap.containsKey(_keyForValue(element));
-  }
-
-  bool get isEmpty => _baseMap.isEmpty;
-
-  bool get isNotEmpty => _baseMap.isNotEmpty;
-
-  int get length => _baseMap.length;
-
-  String toString() => toSet().toString();
-
-  bool add(V value) {
-    K key = _keyForValue(value);
-    bool result = false;
-    _baseMap.putIfAbsent(key, () {
-      result = true;
-      return value;
-    });
-    return result;
-  }
-
-  void addAll(Iterable<V> elements) => elements.forEach(add);
-
-  void clear() => _baseMap.clear();
-
-  bool containsAll(Iterable<Object> other) => other.every(contains);
-
-  /**
-   * Returns a new set with the the elements of [this] that are not in [other].
-   *
-   * That is, the returned set contains all the elements of this [Set] that are
-   * not elements of [other] according to `other.contains`.
-   *
-   * Note that the returned set will use the default equality operation, which
-   * may be different than the equality operation [this] uses.
-   */
-  Set<V> difference(Set<V> other) =>
-      where((element) => !other.contains(element)).toSet();
-
-  /**
-   * Returns a new set which is the intersection between [this] and [other].
-   *
-   * That is, the returned set contains all the elements of this [Set] that are
-   * also elements of [other] according to `other.contains`.
-   *
-   * Note that the returned set will use the default equality operation, which
-   * may be different than the equality operation [this] uses.
-   */
-  Set<V> intersection(Set<Object> other) => where(other.contains).toSet();
-
-  V lookup(Object element) => _baseMap[_keyForValue(element)];
-
-  bool remove(Object value) {
-    if (value != null && value is! V) return false;
-    var key = _keyForValue(value);
-    if (!_baseMap.containsKey(key)) return false;
-    _baseMap.remove(key);
-    return true;
-  }
-
-  void removeAll(Iterable<Object> elements) => elements.forEach(remove);
-
-  void removeWhere(bool test(V element)) {
-    var toRemove = [];
-    _baseMap.forEach((key, value) {
-      if (test(value)) toRemove.add(key);
-    });
-    toRemove.forEach(_baseMap.remove);
-  }
-
-  void retainAll(Iterable<Object> elements) {
-    var valuesToRetain = new Set<V>.identity();
-    for (var element in elements) {
-      if (element != null && element is! V) continue;
-      var key = _keyForValue(element);
-      if (!_baseMap.containsKey(key)) continue;
-      valuesToRetain.add(_baseMap[key]);
-    }
-
-    var keysToRemove = [];
-    _baseMap.forEach((k, v) {
-      if (!valuesToRetain.contains(v)) keysToRemove.add(k);
-    });
-    keysToRemove.forEach(_baseMap.remove);
-  }
-
-  void retainWhere(bool test(V element)) =>
-      removeWhere((element) => !test(element));
-
-  /**
-   * Returns a new set which contains all the elements of [this] and [other].
-   *
-   * That is, the returned set contains all the elements of this [Set] and all
-   * the elements of [other].
-   *
-   * Note that the returned set will use the default equality operation, which
-   * may be different than the equality operation [this] uses.
-   */
-  Set<V> union(Set<V> other) => toSet()..addAll(other);
-}