OLD | NEW |
1 // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file | 1 // Copyright (c) 2013, the Dart project authors. Please see the AUTHORS file |
2 // for details. All rights reserved. Use of this source code is governed by a | 2 // for details. All rights reserved. Use of this source code is governed by a |
3 // BSD-style license that can be found in the LICENSE file. | 3 // BSD-style license that can be found in the LICENSE file. |
4 | 4 |
5 library barback.utils.multiset; | 5 library barback.utils.multiset; |
6 | 6 |
7 import 'dart:collection'; | 7 import 'dart:collection'; |
8 | 8 |
9 /// A set of objects where each object can appear multiple times. | 9 /// A set of objects where each object can appear multiple times. |
10 /// | 10 /// |
(...skipping 11 matching lines...) Expand all Loading... |
22 /// in the set. | 22 /// in the set. |
23 final _map = new Map<E, int>(); | 23 final _map = new Map<E, int>(); |
24 | 24 |
25 Iterator<E> get iterator { | 25 Iterator<E> get iterator { |
26 return _map.keys | 26 return _map.keys |
27 .expand((element) => | 27 .expand((element) => |
28 new Iterable<E>.generate(_map[element], (_) => element)) | 28 new Iterable<E>.generate(_map[element], (_) => element)) |
29 .iterator; | 29 .iterator; |
30 } | 30 } |
31 | 31 |
32 Multiset() | 32 Multiset() : super(); |
33 : super(); | |
34 | 33 |
35 /// Creates a multi-set and initializes it using the contents of [other]. | 34 /// Creates a multi-set and initializes it using the contents of [other]. |
36 Multiset.from(Iterable<E> other) | 35 Multiset.from(Iterable<E> other) : super() { |
37 : super() { | |
38 other.forEach(add); | 36 other.forEach(add); |
39 } | 37 } |
40 | 38 |
41 /// Adds [value] to the set. | 39 /// Adds [value] to the set. |
42 void add(E value) { | 40 void add(E value) { |
43 _map.putIfAbsent(value, () => 0); | 41 _map.putIfAbsent(value, () => 0); |
44 _map[value] += 1; | 42 _map[value] += 1; |
45 } | 43 } |
46 | 44 |
47 /// Removes one copy of [value] from the set. | 45 /// Removes one copy of [value] from the set. |
48 /// | 46 /// |
49 /// Returns whether a copy of [value] was removed, regardless of whether more | 47 /// Returns whether a copy of [value] was removed, regardless of whether more |
50 /// copies remain. | 48 /// copies remain. |
51 bool remove(E value) { | 49 bool remove(E value) { |
52 if (!_map.containsKey(value)) return false; | 50 if (!_map.containsKey(value)) return false; |
53 | 51 |
54 _map[value] -= 1; | 52 _map[value] -= 1; |
55 if (_map[value] == 0) _map.remove(value); | 53 if (_map[value] == 0) _map.remove(value); |
56 return true; | 54 return true; |
57 } | 55 } |
58 | 56 |
59 /// Returns whether [value] is in the set. | 57 /// Returns whether [value] is in the set. |
60 bool contains(Object value) => _map.containsKey(value); | 58 bool contains(Object value) => _map.containsKey(value); |
61 | 59 |
62 /// Returns the number of copies of [value] in the set. | 60 /// Returns the number of copies of [value] in the set. |
63 int count(E value) => _map.containsKey(value) ? _map[value] : 0; | 61 int count(E value) => _map.containsKey(value) ? _map[value] : 0; |
64 } | 62 } |
OLD | NEW |