LanguageFeatures/Spread-collections/DynamicSemantics_Set_A02_t04.dart

/*
 * Copyright (c) 2019, 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 A [set] literal [<E>{elem_1 ... elem_n}] is evaluated as follows:
 *   2. For each element in the [set] literal:
 *      i. Evaluate the element's expression to a value value.
 *      ii. If element is a spread element:
 *          a. If element is null-aware and value is [null], continue to the
 *             next element in the literal.
 *          b. Evaluate [value.iterator] to a [value] iterator.
 *          c. Loop:
 *             a. If [iterator.moveNext()] returns [false], exit the loop.
 *             b. Evaluate set.add(iterator.current).
 *       iii. Else:
 *           a. Evaluate [set.add(value)].
 * @description Checks that elements are added to the result set in correct
 * order.
 * @static-warning
 * @author iarkh@unipro.ru
 */

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

class MyIterable extends IterableBase {
  late List list;

  MyIterable(this.list);

  Iterator get iterator => MyIterator(list);
}

class MyIterator extends Iterator {
  int i = -1;
  late List list;

  MyIterator(List aList) { list = aList; }

  @override
  bool moveNext() { return ++i < list.length; }

  @override
  dynamic get current { return list[i]; }
}

List aList = [11, 234];
Map aMap = {};

Iterable it1 = new MyIterable([1, 2, 3, 4, 5]);
Iterable it2 = new MyIterable(["a", "14", "1", "2", null, 143, aList]);
Iterable it3 = [100, 200, aMap, aList, 300];
Iterable it4 = [];
Iterable? it5 = null;

main() {
  Expect.setEquals(
      {-1, -2, -3, 1, 2, 3, 4, 5, 6, 7}, {-1, -2, -3, ...it1, 6, 7});
  Expect.setEquals(
      {-1, -2, -3, 1, 2, 3, 4, 5, 6, 7}, {-1, -2, -3, ...?it1, 6, 7});
  Expect.setEquals({1, 2, 3}, {1, ...it4, 2, ...?it4, 3, ...?it5});
  Expect.setEquals({-9, -8, 1, 2, 3, 4, 5, -7, "a", "14", "1", "2", null, 143,
          -6, 100, 200, aMap, aList, 300, -5, -4, -3, -2},
      {-9, -8, ...it1, -7, ...?it2, -6, ...it3, -5, -4, ...it4, -3, -2});
}