Add "last" setter to List.

tests/corelib/list_test.dart

 // Copyright (c) 2011, 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.
 
 import "dart:collection";
 import "dart:typed_data";
 import "package:expect/expect.dart";
 
 void main() {
   // Typed lists - fixed length and can only contain integers.
@@ skipping 27 matching lines @@
   testGrowableList(new MyList([]));
   testGrowableList(new MyList([]).toList());
 
   testTypedGrowableList(new Uint8List(0).toList());
   testTypedGrowableList(new Int8List(0).toList());
   testTypedGrowableList(new Uint16List(0).toList());
   testTypedGrowableList(new Int16List(0).toList());
   testTypedGrowableList(new Uint32List(0).toList());
   testTypedGrowableList(new Int32List(0).toList());
 
+  // Lists based on ListBase and ListMixin.
+  testGrowableList(new BaseList());
+  testGrowableList(new BaseList().toList());
+  testGrowableList(new MixinList());
+  testGrowableList(new MixinList().toList());
+
   testListConstructor();
 }
 
 void testLength(int length, List list) {
   Expect.equals(length, list.length);
   (length == 0 ? Expect.isTrue : Expect.isFalse)(list.isEmpty);
   (length != 0 ? Expect.isTrue : Expect.isFalse)(list.isNotEmpty);
 }
 
 void testTypedLengthInvariantOperations(List list) {
   // length
   Expect.equals(list.length, 4);
   // operators [], []=.
   for (int i = 0; i < 4; i++) list[i] = 0;
   list[0] = 4;
   Expect.listEquals([4, 0, 0, 0], list);
   list[1] = 7;
   Expect.listEquals([4, 7, 0, 0], list);
   list[3] = 2;
   Expect.listEquals([4, 7, 0, 2], list);
 
   for (int i = 0; i < list.length; i++) {
     list[i] = i;
   }
 
+  // last=
+  Expect.listEquals([0, 1, 2, 3], list);
+  list.last = 47;
+  Expect.listEquals([0, 1, 2, 47], list);
+  list.last -= 5;
+  Expect.listEquals([0, 1, 2, 42], list);
+  list.last++;
+  Expect.listEquals([0, 1, 2, 43], list);
+  ++list.last;
+  Expect.listEquals([0, 1, 2, 44], list);
+  list.last--;
+  Expect.listEquals([0, 1, 2, 43], list);
+  --list.last;
+  Expect.listEquals([0, 1, 2, 42], list);
+  list.last = 3;
+  Expect.listEquals([0, 1, 2, 3], list);
+
   // indexOf, lastIndexOf
   for (int i = 0; i < 4; i++) {
     Expect.equals(i, list[i]);
     Expect.equals(i, list.indexOf(i));
     Expect.equals(i, list.lastIndexOf(i));
   }
 
   // setRange.
   list.setRange(0, 4, [3, 2, 1, 0]);
   Expect.listEquals([3, 2, 1, 0], list);
@@ skipping 414 matching lines @@
 
 void testListConstructor() {
   Expect.throws(() { new List(0).add(4); });  // Is fixed-length.
   Expect.throws(() { new List(-2); });  // Not negative. /// 01: ok
   Expect.throws(() { new List(null); });  // Not null.
   Expect.listEquals([4], new List()..add(4));
   Expect.throws(() { new List.filled(0, 42).add(4); });  // Is fixed-length.
   Expect.throws(() { new List.filled(-2, 42); });  // Not negative.
   Expect.throws(() { new List.filled(null, 42); });  // Not null.
 }
+
+abstract class ListImpl<E>{
+  List _base = [];
+  int get length => _base.length;
+  void set length(int length) { _base.length = length; }
+  E operator[](int index) => _base[index];
+  void operator[]=(int index, E value) { _base[index] = value; }
+}
+
+class BaseList<E> = ListBase<E> with ListImpl<E>;
+
+class MixinList<E> = ListImpl<E> with ListMixin<E>;