| // Copyright (c) 2017, 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 expand(Iterable f(E element)) |
| /// ... |
| /// The returned Iterable is lazy, and calls f for each element of this every |
| /// time it's iterated. |
| /// @description Checks that the returned [Iterable] is lazy, and calls f for |
| /// each element of this every time it's iterated. |
| /// @author ngl@unipro.ru |
| |
| |
| import "dart:typed_data"; |
| import "../../../Utils/expect.dart"; |
| |
| main() { |
| var l = new Int16List.fromList([1, 2, 3, 4]); |
| var counter = 0; |
| var res = l.expand((element) {counter++; return [element * 2];}); |
| var it = res.iterator; |
| Expect.equals(0, counter); |
| int i = 0; |
| while (it.moveNext()) { |
| Expect.equals(++i, counter); |
| } |
| Expect.equals(l.length, i); |
| } |