Add Map constructors taking iterables.

tests/corelib/map_from_iterables_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 "package:expect/expect.dart";
+import 'dart:collection';
+
+main() {
+  positiveTest();
+  emptyMapTest();
+  fewerKeysIterableTest();
+  fewerValuesIterableTest();
+  identicalElementsTest();
+}
+
+void positiveTest() {
+  var map = new Map.fromIterables([1, 2, 3], ["one", "two", "three"]);

[floitsch, 2013/06/27 11:45:04]

write at least one test with generic types.

[zarah, 2013/06/27 13:02:43]

Done.

+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(3, map.length);
+  Expect.equals(3, map.keys.length);
+  Expect.equals(3, map.values.length);
+
+  Expect.equals("one", map[1]);
+  Expect.equals("two", map[2]);
+  Expect.equals("three", map[3]);
+}
+
+void emptyMapTest() {
+  var map = new Map.fromIterables([], []);
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(0, map.length);
+  Expect.equals(0, map.keys.length);
+  Expect.equals(0, map.values.length);
+}
+
+void fewerValuesIterableTest() {
+  Expect.throws(() => new Map.fromIterables([1,2], [0]));
+}
+
+void fewerKeysIterableTest() {
+  Expect.throws(() => new Map.fromIterables([1], [0,2]));
+}
+
+void identicalElementsTest() {

[floitsch, 2013/06/27 11:45:04]

equalElementsTest (although they are identical here)

[zarah, 2013/06/27 13:02:43]

Done.

+  var map = new Map.fromIterables([1, 2, 2], ["one", "two", "three"]);
+  Expect.isTrue(map is Map);
+  Expect.isTrue(map is HashMap);
+
+  Expect.equals(2, map.length);
+  Expect.equals(2, map.keys.length);
+  Expect.equals(2, map.values.length);
+
+  Expect.equals("one", map[1]);
+  Expect.equals("three", map[2]);
+}