// 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 abstract E reduce(E combine(E value, E element))
/// If it has only one element, that element is returned.
/// @description Checks that if there is only one element in the queue, it is
/// returned.
/// @author kaigorodov


import "dart:collection";
import "../../../Utils/expect.dart";

check(List list, combine, num expected) {
  DoubleLinkedQueue queue = new DoubleLinkedQueue();
  queue.addAll(list);
  num actual = queue.reduce(combine);
  Expect.equals(expected, actual);
}	

main() {
  check([1], (value, element) => value + element, 1);
  check([8], (value, element) => value * element, 8);
  check([-3], (value, element) => value * element, -3);
}