| // 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. |
| |
| // @dart = 2.9 |
| |
| /// @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 calls f for each element of this |
| /// every time it's iterated. |
| /// @author kaigorodov |
| |
| import "../../../Utils/expect.dart"; |
| import "dart:collection"; |
| |
| int count=0; |
| |
| Iterable f(int element) { |
| count++; |
| return [count]; |
| } |
| |
| main() { |
| DoubleLinkedQueue<int> queue = new DoubleLinkedQueue<int>(); |
| |
| for (int k = 0; k < 10; k++) { |
| queue.add(k); |
| } |
| |
| Iterable expanded = queue.expand(f); |
| int count2 = 0; |
| |
| for (int k = 1; k < 10; k++) { |
| Iterator it=expanded.iterator; |
| while (it.moveNext()) { |
| count2++; |
| Expect.equals(count2, it.current); |
| } |
| } |
| |
| } |