| // 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 T fold<T>(T initialValue, T combine(T previousValue, E element)) |
| /// Reduces a collection to a single value by iteratively combining each |
| /// element of the collection with an existing value. |
| /// Uses initialValue as the initial value, and the function combine |
| /// to create a new value, then iterates through the elements and updates the |
| /// value with each element using the combine function. |
| /// @description Checks that the returned value is correct. |
| /// @author msyabro |
| |
| |
| import "dart:typed_data"; |
| import "../../../Utils/expect.dart"; |
| |
| checkInt(List<int> list, int expected) { |
| var l = new Int64List.fromList(list); |
| var res = l.fold(0, (num prev, num cur) => prev + cur); |
| Expect.equals(expected, res); |
| } |
| |
| checkString(List<int> list, String expected) { |
| var l = new Int64List.fromList(list); |
| var res = l.fold("", (prev, cur) => "${prev}${cur}"); |
| Expect.equals(expected, res); |
| } |
| |
| checkConst(List<int> list, int expected) { |
| var l = new Int64List.fromList(list); |
| var res = l.fold(0, (prev, cur) => 1); |
| Expect.equals(expected, res); |
| } |
| |
| |
| main() { |
| checkInt([], 0); |
| checkInt([1, 2, 3, 4, 5, 6, 7, 8, 9, 10], 55); |
| checkInt([10, -1, -2, -3, -4], 0); |
| |
| checkString([], ""); |
| checkString([1], "1"); |
| checkString([1, 2, 3, 4, 5], "12345"); |
| |
| checkConst([], 0); |
| checkConst([1, 2, 3], 1); |
| } |