| // Copyright (c) 2013, 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. |
| |
| /** |
| * @assertion Iterable<E> takeWhile(bool test(E element)) |
| * The filtering happens lazily. |
| * @description Checks that [test] is not invoked until returned |
| * [Iterable] is not iterated. |
| * @author msyabro |
| */ |
| import "../../../Utils/expect.dart"; |
| |
| main() { |
| var count = 0; |
| test(e) { |
| ++count; |
| return true; |
| } |
| |
| var runes = new Runes('abc'); |
| var res = runes.takeWhile(test); |
| Expect.equals(0, count); |
| res.elementAt(0); |
| Expect.equals(1, count); |
| } |
