LibTest/collection/SplayTreeMap/SplayTreeMap.from_A03_t02.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.
 */
/**
 * @assertion SplayTreeMap.from(Map other, [int compare(K key1, K key2),
 * bool isValidKey(potentialKey)])
 * Creates a SplayTreeMap that contains all key/value pairs of other.
 * @description Checks that if isValidKey supplied and returns false then
 * element is assumed not to be in a map
 * @author sgrekhov@unipro.ru
 */
import "dart:collection";
import "../../../Utils/expect.dart";

class C {
  int value;
  C(this.value);
}

int compare(C key1, C key2) {
  return key1.value - key2.value;
}

bool isValidKey(C potentialKey) => potentialKey.value != 3;

main() {
  C c1 = new C(1);
  C c2 = new C(2);
  C c3 = new C(3);

  Map source = {c1: 1, c2: 2, c3: 3};
  SplayTreeMap map = new SplayTreeMap.from(source, compare, isValidKey);

  Expect.equals(3, map.length);
  Expect.isNull(map[c3]);
  Expect.isFalse(map.containsKey(c3));
  Expect.isNull(map.remove(c3));
}