Combine unmodifiable_collection package into collection_helpers.

pkg/collection_helpers/lib/unmodifiable_wrappers.dart

Index: pkg/collection_helpers/lib/unmodifiable_wrappers.dart
diff --git a/pkg/unmodifiable_collection/lib/unmodifiable_collection.dart b/pkg/collection_helpers/lib/unmodifiable_wrappers.dart
similarity index 57%
rename from pkg/unmodifiable_collection/lib/unmodifiable_collection.dart
rename to pkg/collection_helpers/lib/unmodifiable_wrappers.dart
index 9fd35e8a4c6db9338dcc3189d3b81a13ff54c31d..b44337f844a6eb8820e36e0416de1b99183024be 100644
--- a/pkg/unmodifiable_collection/lib/unmodifiable_collection.dart
+++ b/pkg/collection_helpers/lib/unmodifiable_wrappers.dart
@@ -3,7 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 /**
- * Wrappers that prevent List, Set, or Map objects from being modified.
+ * Wrappers that prevent a List, Set, or Map object from being modified.
  *
  * The [Set] and [Map] wrappers allow reading from the wrapped collection,
  * but prohibit writing.
@@ -11,69 +11,36 @@
  * The [List] wrapper prevents changes to the length of the wrapped list,
  * but allows changes to the contents.
  */
-library unmodifiable_collection;
-
-import "dart:math" show Random;
-export "dart:collection" show UnmodifiableListView;
+part of dart.collection_helpers.wrappers;
 
 /**
  * A fixed-length list.
  *
- * A NonGrowableListView contains a [List] object and ensures that
+ * A `NonGrowableListView` contains a [List] object and ensures that
  * its length does not change.
  * Methods that would change the length of the list,
  * such as [add] and [remove], throw an [UnsupportedError].
+ * All other methods work directly on the underlying list.
  *
  * This class _does_ allow changes to the contents of the wrapped list.
  * You can, for example, [sort] the list.
  * Permitted operations defer to the wrapped list.
  */
-class NonGrowableListView<E> extends _IterableView<E>
-                                     implements List<E> {
-  List<E> _source;
-  NonGrowableListView(List<E> source) : _source = source;
+class NonGrowableListView<E> extends DelegatingList<E>
+                             with NonGrowableListMixin<E> {
+  NonGrowableListView(List<E> listBase) : super(listBase);
+}
 
+/**
+ * Mixin class that implements a throwing version of all list operations that
+ * change the List's length.
+ */
+abstract class NonGrowableListMixin<E> implements List<E> {
   static void _throw() {
     throw new UnsupportedError(
         "Cannot change the length of a fixed-length list");
   }
 
-  int get length => _source.length;
-
-  E operator [](int index) => _source[index];
-
-  int indexOf(E element, [int start = 0]) => _source.indexOf(element, start);
-
-  int lastIndexOf(E element, [int start])
-      => _source.lastIndexOf(element, start);
-
-  Iterable<E> getRange(int start, int end) => _source.getRange(start, end);
-
-  List<E> sublist(int start, [int end]) => _source.sublist(start, end);
-
-  Iterable<E> get reversed => _source.reversed;
-
-  Map<int, E> asMap() => _source.asMap();
-
-  void operator []=(int index, E value) { _source[index] = value; }
-
-  void sort([int compare(E a, E b)]) { _source.sort(compare); }
-
-  void shuffle([Random random]) { _source.shuffle(random); }
-
-  void setRange(int start, int end, Iterable<E> iterable, [int skipCount = 0]) {
-    _source.setRange(start, end, iterable, skipCount);
-  }
-
-  void fillRange(int start, int end, [E fillValue]) {
-    _source.fillRange(start, end, fillValue);
-  }
-
-  void setAll(int index, Iterable<E> iterable) {
-    _source.setAll(index, iterable);
-  }
-
-
   /**
    * Throws an [UnsupportedError];
    * operations that change the length of the list are disallowed.
@@ -164,25 +131,20 @@ class NonGrowableListView<E> extends _IterableView<E>
  * such as [add] and [remove], throw an [UnsupportedError].
  * Permitted operations defer to the wrapped set.
  */
-class UnmodifiableSetView<E> extends _IterableView<E>
-                                      implements Set<E> {
-  Set<E> _source;
-  UnmodifiableSetView(Set<E> source) : _source = source;
+class UnmodifiableSetView<E> extends DelegatingSet<E>
+                             with UnmodifiableSetMixin<E> {
+  UnmodifiableSetView(Set<E> setBase) : super(setBase);
+}
 
+/**
+ * Mixin class that implements a throwing version of all set operations that
+ * change the Set.
+ */
+abstract class UnmodifiableSetMixin<E> implements Set<E> {
   void _throw() {
     throw new UnsupportedError("Cannot modify an unmodifiable Set");
   }
 
-  bool containsAll(Iterable<E> other) => _source.containsAll(other);
-
-  Set<E> intersection(Set<E> other) => _source.intersection(other);
-
-  Set<E> union(Set<E> other) => _source.union(other);
-
-  Set<E> difference(Set<E> other) => _source.difference(other);
-
-  E lookup(Object object) => _source.lookup(object);
-
   /**
    * Throws an [UnsupportedError];
    * operations that change the set are disallowed.
@@ -243,33 +205,20 @@ class UnmodifiableSetView<E> extends _IterableView<E>
  * such as [addAll] and [remove], throw an [UnsupportedError].
  * Permitted operations defer to the wrapped map.
  */
-class UnmodifiableMapView<K, V> implements Map<K, V> {
-  Map<K, V> _source;
-  UnmodifiableMapView(Map<K, V> source) : _source = source;
+class UnmodifiableMapView<K, V> extends DelegatingMap<K, V>
+                                with UnmodifiableMapMixin<K, V> {
+  UnmodifiableMapView(Map<K, V> baseMap) : super(baseMap);
+}
 
+/**
+ * Mixin class that implements a throwing version of all map operations that
+ * change the Map.
+ */
+abstract class UnmodifiableMapMixin<K, V> implements Map<K, V> {
   static void _throw() {
     throw new UnsupportedError("Cannot modify an unmodifiable Map");
   }
 
-  int get length => _source.length;
-
-  bool get isEmpty => _source.isEmpty;
-
-  bool get isNotEmpty => _source.isNotEmpty;
-
-  V operator [](K key) => _source[key];
-
-  bool containsKey(K key) => _source.containsKey(key);
-
-  bool containsValue(V value) => _source.containsValue(value);
-
-  void forEach(void f(K key, V value)) => _source.forEach(f);
-
-  Iterable<K> get keys => _source.keys;
-
-  Iterable<V> get values => _source.values;
-
-
   /**
    * Throws an [UnsupportedError];
    * operations that change the map are disallowed.
@@ -300,65 +249,3 @@ class UnmodifiableMapView<K, V> implements Map<K, V> {
    */
   void clear() => _throw();
 }
-
-abstract class _IterableView<E> {
-  Iterable<E> get _source;
-
-  bool any(bool test(E element)) => _source.any(test);
-
-  bool contains(E element) => _source.contains(element);
-
-  E elementAt(int index) => _source.elementAt(index);
-
-  bool every(bool test(E element)) => _source.every(test);
-
-  Iterable expand(Iterable f(E element)) => _source.expand(f);
-
-  E get first => _source.first;
-
-  E firstWhere(bool test(E element), { E orElse() })
-      => _source.firstWhere(test, orElse: orElse);
-
-  dynamic fold(var initialValue,
-               dynamic combine(var previousValue, E element))
-      => _source.fold(initialValue, combine);
-
-  void forEach(void f(E element)) => _source.forEach(f);
-
-  bool get isEmpty => _source.isEmpty;
-
-  bool get isNotEmpty => _source.isNotEmpty;
-
-  Iterator<E> get iterator => _source.iterator;
-
-  String join([String separator = ""]) => _source.join(separator);
-
-  E get last => _source.last;
-
-  E lastWhere(bool test(E element), {E orElse()})
-      => _source.lastWhere(test, orElse: orElse);
-
-  int get length => _source.length;
-
-  Iterable map(f(E element)) => _source.map(f);
-
-  E reduce(E combine(E value, E element)) => _source.reduce(combine);
-
-  E get single => _source.single;
-
-  E singleWhere(bool test(E element)) => _source.singleWhere(test);
-
-  Iterable<E> skip(int n) => _source.skip(n);
-
-  Iterable<E> skipWhile(bool test(E value)) => _source.skipWhile(test);
-
-  Iterable<E> take(int n) => _source.take(n);
-
-  Iterable<E> takeWhile(bool test(E value)) => _source.takeWhile(test);
-
-  List<E> toList({ bool growable: true }) => _source.toList(growable: growable);
-
-  Set<E> toSet() => _source.toSet();
-
-  Iterable<E> where(bool test(E element)) => _source.where(test);
-}