| // Copyright (c) 2023, 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. |
| |
| // This test captures the changes introduced in 2.29 of the patterns proposal. |
| import 'dart:collection'; |
| |
| import "package:expect/expect.dart"; |
| |
| main() { |
| var map = {'a': 1, 'b': 2}; |
| |
| // Map patterns don't access length. |
| Expect.isTrue(switch (NoLengthMap(map)) { {'a': _} => true, _ => false }); |
| |
| // Map patterns match even if there are extra keys. |
| Expect.equals( |
| 'a b', |
| switch (map) { |
| {'a': _, 'b': _} => 'a b', |
| {'a': _} => 'a', |
| {'b': _} => 'b', |
| _ => '???' |
| }); |
| } |
| |
| class NoLengthMap extends MapBase<String, int> { |
| final Map<String, int> _inner; |
| |
| NoLengthMap(this._inner); |
| |
| @override |
| int get length => throw UnsupportedError('No length!'); |
| |
| @override |
| int? operator [](Object? key) => _inner[key]; |
| |
| @override |
| void operator []=(String key, int value) => _inner[key] = value; |
| |
| @override |
| void clear() => _inner.clear(); |
| |
| @override |
| Iterable<String> get keys => _inner.keys; |
| |
| @override |
| int? remove(Object? key) => _inner.remove(key); |
| } |