Merge branch 'master' into core-libs-dart-3

* master:
  Add new Dart 2 Iterable and List methods (google#422)
  Document google#373 as breaking change (google#424)

CHANGELOG.md

@@ -1,5 +1,9 @@
 #### Master
 
+   * New: DelegatingIterable now includes a real implementation of
+     `followedBy`, and accepts the `orElse` parameter on `singleWhere`.
+   * New: DelegatingList now includes real implementations of `operator +`,
+     `indexWhere`, and `lastIndexWhere`.
    * New: The map returned by `Multimap.asMap()` now includes real
      implementations of `get entries` and `removeWhere`. This class also has
      "real" implementations of `addEntries`, `map`, `update`, and `updateAll`,
@@ -53,6 +57,9 @@
      `extent`, `forEachAsync`, `max`, `merge`, `min`, `reduceAsync`, and `zip`
      are now type parameterized. Depending on the inferred value of each type
      parameter, the return type of each function may change in existing code.
+   * BREAKING CHANGE: `Optional`'s `==` operator now takes into account `T`,
+     the type of the value. This changes, e.g. `Optional<int>.absent()` to no
+     longer be equal to `Optional<String>.absent()`.
    * Deprecated: `reverse` in the `strings` library. No replacement is
      provided.
    * Deprecated: `createTimer`, `createTimerPeriodic` in the `async` library.

lib/src/collection/delegates/iterable.dart

@@ -53,11 +53,7 @@ abstract class DelegatingIterable<E> implements Iterable<E> {
       delegate.fold(initialValue, combine);
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
-  Iterable<E> followedBy(Iterable<E> other) {
-    throw new UnimplementedError("followedBy");
-  }
+  Iterable<E> followedBy(Iterable<E> other) => delegate.followedBy(other);
 
   void forEach(void f(E element)) => delegate.forEach(f);
 
@@ -89,10 +85,8 @@ abstract class DelegatingIterable<E> implements Iterable<E> {
 
   E get single => delegate.single;
 
-  E singleWhere(bool test(E element), {E orElse()}) {
-    if (orElse != null) throw new UnimplementedError("singleWhere:orElse");
-    return delegate.singleWhere(test);
-  }
+  E singleWhere(bool test(E element), {E orElse()}) =>
+      delegate.singleWhere(test, orElse: orElse);
 
   Iterable<E> skip(int n) => delegate.skip(n);
 

lib/src/collection/delegates/list.dart

@@ -35,11 +35,7 @@ abstract class DelegatingList<E> extends DelegatingIterable<E>
   }
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
-  List<E> operator +(List<E> other) {
-    throw new UnimplementedError("+");
-  }
+  List<E> operator +(List<E> other) => delegate + other;
 
   void add(E value) => delegate.add(value);
 
@@ -79,20 +75,15 @@ abstract class DelegatingList<E> extends DelegatingIterable<E>
   int indexOf(E element, [int start = 0]) => delegate.indexOf(element, start);
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
-  int indexWhere(bool test(E element), [int start = 0]) {
-    throw new UnimplementedError("indexWhere");
-  }
+  int indexWhere(bool test(E element), [int start = 0]) =>
+      delegate.indexWhere(test, start);
 
   void insert(int index, E element) => delegate.insert(index, element);
 
   void insertAll(int index, Iterable<E> iterable) =>
       delegate.insertAll(index, iterable);
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_setter
   void set last(E element) {
     if (this.isEmpty) throw new RangeError.index(0, this);
     this[this.length - 1] = element;
@@ -102,11 +93,8 @@ abstract class DelegatingList<E> extends DelegatingIterable<E>
       delegate.lastIndexOf(element, start);
 
   @override
-  // TODO: Dart 2.0 requires this method to be implemented.
-  // ignore: override_on_non_overriding_method
-  int lastIndexWhere(bool test(E element), [int start]) {
-    throw new UnimplementedError("lastIndexWhere");
-  }
+  int lastIndexWhere(bool test(E element), [int start]) =>
+      delegate.lastIndexWhere(test, start);
 
   void set length(int newLength) {
     delegate.length = newLength;

lib/src/collection/multimap.dart

@@ -639,6 +639,7 @@ class _WrappedList<K, V> extends _WrappedIterable<K, V, List<V>>
 
   @override
   int lastIndexWhere(bool test(V element), [int start]) {
+    _syncDelegate();
     return _delegate.lastIndexWhere(test, start);
   }
 

test/collection/delegates/iterable_test.dart

@@ -87,6 +87,13 @@ void main() {
       expect(new MyIterable([]).isNotEmpty, isFalse);
     });
 
+    test('followedBy', () {
+      expect(delegatingIterable.followedBy(['d', 'e']),
+          equals(['a', 'b', 'cc', 'd', 'e']));
+      expect(delegatingIterable.followedBy(delegatingIterable),
+          equals(['a', 'b', 'cc', 'a', 'b', 'cc']));
+    });
+
     test('forEach', () {
       final it = delegatingIterable.iterator;
       expect(it.current, isNull);
@@ -138,6 +145,8 @@ void main() {
       expect(delegatingIterable.singleWhere((e) => e == 'b'), equals('b'));
       expect(() => delegatingIterable.singleWhere((e) => e == 'd'),
           throwsStateError);
+      expect(delegatingIterable.singleWhere((e) => e == 'd', orElse: () => 'X'),
+          equals('X'));
     });
 
     test('skip', () {

test/collection/delegates/list_test.dart

@@ -45,6 +45,11 @@ void main() {
       expect(delegatingList, equals(['d', 'b', 'cc']));
     });
 
+    test('+', () {
+      var sum = delegatingList + ['d', 'e'];
+      expect(sum, equals(['a', 'b', 'cc', 'd', 'e']));
+    });
+
     test('add', () {
       delegatingList.add('d');
       expect(delegatingList, equals(['a', 'b', 'cc', 'd']));
@@ -82,6 +87,11 @@ void main() {
       expect(delegatingList.indexOf('cc', 1), equals(2));
     });
 
+    test('indexWhere', () {
+      delegatingList.add('bb');
+      expect(delegatingList.indexWhere((e) => e.length > 1), equals(2));
+    });
+
     test('insert', () {
       delegatingList.insert(1, 'd');
       expect(delegatingList, equals(['a', 'd', 'b', 'cc']));
@@ -98,6 +108,11 @@ void main() {
       expect(delegatingList.lastIndexOf('cc', 1), equals(-1));
     });
 
+    test('lastIndexWhere', () {
+      delegatingList.add('bb');
+      expect(delegatingList.lastIndexWhere((e) => e.length > 1), equals(3));
+    });
+
     test('set length', () {
       delegatingList.length = 2;
       expect(delegatingList, equals(['a', 'b']));