| // 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 LinkedHashMap({bool equals(K key1, K key2), int hashCode(K key), |
| /// bool isValidKey(potentialKey)}) |
| /// ... |
| /// If using methods like operator [], [remove] and [containsKey] together with a |
| /// custom equality and hashcode, an extra [isValidKey] function can be supplied. |
| /// This function is called before calling [equals] or [hashCode] with an |
| /// argument that may not be a [K] instance, and if the call returns [false], the |
| /// key is assumed to not be in the set. The [isValidKey] function defaults to |
| /// just testing if the object is a [K] instance. |
| /// @description Checks that if [isValidKey] returns [false] then the key is |
| /// assumed to not be in the set |
| /// @author sgrekhov@unipro.ru |
| |
| import "../../../Utils/expect.dart"; |
| import "dart:collection"; |
| |
| bool myEquals(var key1, var key2) { |
| return key1 == key2; |
| } |
| |
| int myHashCode(var key) { |
| return key.hashCode; |
| } |
| |
| bool isValidKey(var potentialKey) { |
| return (potentialKey is int) && potentialKey < 100; |
| } |
| |
| main() { |
| LinkedHashMap map = new LinkedHashMap(equals: myEquals, hashCode: myHashCode, |
| isValidKey: isValidKey); |
| |
| map[1] = 11; |
| Expect.equals(11, map[1]); |
| Expect.isTrue(map.containsKey(1)); |
| Expect.equals(11, map.remove(1)); |
| Expect.isFalse(map.containsKey(1)); |
| |
| map[101] = 11; |
| Expect.isNull(map[101]); |
| Expect.isFalse(map.containsKey(101)); |
| Expect.isNull(map.remove(101)); |
| } |