Added new version of reduce.

tests/corelib/iterable_min_max_test.dart

-// Copyright (c) 2012, 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.
-
-library iterable_min_max_test;
-
-import "package:expect/expect.dart";
-import "dart:collection";
-
-class C {
-  final x;
-  const C(this.x);
-  int get hashCode => x.hashCode;
-  bool operator==(var other) => other is C && x == other.x;
-}
-
-const inf = double.INFINITY;
-
-var intList = const [0, 1, -1, -5, 5, -1000, 1000, -7, 7];
-var doubleList = const [-0.0, 0.0, -1.0, 1.0, -1000.0, 1000.0, -inf, inf];
-var stringList = const ["bbb", "bba", "bab", "abb", "bbc", "bcb", "cbb", "bb"];
-var cList = const [const C(5), const C(3), const C(8),
-                   const C(0), const C(10), const C(6)];
-int compareC(C a, C b) => a.x.compareTo(b.x);
-
-
-testMinMax(iterable, min, max) {
-  Expect.equals(min, iterable.min());
-  Expect.equals(min, iterable.min(Comparable.compare));
-  Expect.equals(max, iterable.min((a, b) => Comparable.compare(b, a)));
-
-  Expect.equals(max, iterable.max());
-  Expect.equals(max, iterable.max(Comparable.compare));
-  Expect.equals(min, iterable.max((a, b) => Comparable.compare(b, a)));
-}
-
-
-main() {
-  testMinMax(const [], null, null);
-  testMinMax([], null, null);
-  testMinMax(new Set(), null, null);
-
-  testMinMax(intList, -1000, 1000);  // Const list.
-  testMinMax(new List.from(intList), -1000, 1000);  // Non-const list.
-  testMinMax(new Set.from(intList), -1000, 1000);  // Set.
-
-  testMinMax(doubleList, -inf, inf);
-  testMinMax(new List.from(doubleList), -inf, inf);
-  testMinMax(new Set.from(doubleList), -inf, inf);
-
-  testMinMax(stringList, "abb", "cbb");
-  testMinMax(new List.from(stringList), "abb", "cbb");
-  testMinMax(new Set.from(stringList), "abb", "cbb");
-
-  // Objects that are not Comparable.
-  Expect.equals(const C(0), cList.min(compareC));
-  Expect.equals(const C(0), new List.from(cList).min(compareC));
-  Expect.equals(const C(0), new Set.from(cList).min(compareC));
-
-  Expect.equals(const C(10), cList.max(compareC));
-  Expect.equals(const C(10), new List.from(cList).max(compareC));
-  Expect.equals(const C(10), new Set.from(cList).max(compareC));
-
-  bool checkedMode = false;
-  assert(checkedMode = true);
-  Expect.throws(cList.min, (e) => checkedMode ? e is TypeError
-                                              : e is NoSuchMethodError);
-  Expect.throws(cList.max, (e) => checkedMode ? e is TypeError
-                                              : e is NoSuchMethodError);
-}