LibTest/collection/SplayTreeSet/SplayTreeSet.from_A02_t04.dart

// Copyright (c) 2016, 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 SplayTreeSet.from(Iterable elements, [int compare(E key1, E key2),
/// bool isValidKey(potentialKey)])
/// ...
/// The set works as if created by new SplayTreeSet<E>(compare, isValidKey).
/// @description Checks that if the compare function is omitted, it defaults to
/// Comparable.compare
/// @author sgrekhov@unipro.ru

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

class C implements Comparable {
  int value;
  C(this.value);

  compareTo(dynamic other) {
    return this.value - other.value;
  }
}

main() {
  C c1 = new C(2);
  C c2 = new C(1);
  C c3 = new C(-1);
  C c4 = new C(1);

  SplayTreeSet set = new SplayTreeSet.from([c1, c2, c3, c4]);
  Expect.equals(3, set.length);
  Expect.equals(c3, set.elementAt(0));
  Expect.equals(c2, set.elementAt(1));
  Expect.equals(c1, set.elementAt(2));
}