| // 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)) |
| /// Returns a lazy [iterable] of the leading elements satisfying test. |
| /// @description Checks that all first elements that satisfy test are retained, |
| /// and elements after that are skipped. |
| /// @author msyabro |
| |
| |
| import "dart:typed_data"; |
| import "../../../Utils/expect.dart"; |
| |
| void check(List<int> list, bool test(int element)) { |
| var l = new Uint8List.fromList(list); |
| var it0 = l.iterator; |
| var res = l.takeWhile(test); |
| var it = res.iterator; |
| var skipCount = 0; |
| |
| // check that the beginning of a0 is identical to a |
| var hasNext0 = it0.moveNext(); |
| var len = 0; |
| for (;;) { |
| bool hasNext = it.moveNext(); |
| if (!hasNext) break; |
| Expect.isTrue(test(it0.current)); |
| Expect.equals(it0.current, it.current); |
| len++; |
| hasNext0 = it0.moveNext(); |
| } |
| Expect.equals(len, res.length); |
| |
| // count the rest |
| while (hasNext0) { |
| skipCount++; |
| hasNext0 = it0.moveNext(); |
| } |
| |
| Expect.equals(l.length, len+skipCount); |
| } |
| |
| main() { |
| var a0 = [1, 3, 7, 4, 5, 6]; |
| check(a0, (var element) => element == 1); |
| check(a0, (var element) => true); |
| check(a0, (var element) => false); |
| check(a0, (var element) => element > 4); |
| check(a0, (var element) => element < 4); |
| check(a0, (var element) => element == 4); |
| } |