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1 // Copyright (c) 2012, the Dart project authors. Please see the AUTHORS file | 1 // Copyright (c) 2012, 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 part of yaml; | 5 part of yaml; |
6 | 6 |
7 /** | 7 /// This class wraps behaves almost identically to the normal Dart Map |
8 * This class wraps behaves almost identically to the normal Dart Map | 8 /// implementation, with the following differences: |
9 * implementation, with the following differences: | 9 /// |
10 * | 10 /// * It allows null, NaN, boolean, list, and map keys. |
11 * * It allows null, NaN, boolean, list, and map keys. | 11 /// * It defines `==` structurally. That is, `yamlMap1 == yamlMap2` if they |
12 * * It defines `==` structurally. That is, `yamlMap1 == yamlMap2` if they have | 12 /// have the same contents. |
13 * the same contents. | 13 /// * It has a compatible [hashCode] method. |
14 * * It has a compatible [hashCode] method. | |
15 */ | |
16 class YamlMap implements Map { | 14 class YamlMap implements Map { |
17 Map _map; | 15 Map _map; |
18 | 16 |
19 YamlMap() : _map = new Map(); | 17 YamlMap() : _map = new Map(); |
20 | 18 |
21 YamlMap.from(Map map) : _map = new Map.from(map); | 19 YamlMap.from(Map map) : _map = new Map.from(map); |
22 | 20 |
23 YamlMap._wrap(this._map); | 21 YamlMap._wrap(this._map); |
24 | 22 |
25 bool containsValue(value) => _map.containsValue(value); | 23 bool containsValue(value) => _map.containsValue(value); |
(...skipping 11 matching lines...) Expand all Loading... |
37 bool get isEmpty => _map.isEmpty; | 35 bool get isEmpty => _map.isEmpty; |
38 String toString() => _map.toString(); | 36 String toString() => _map.toString(); |
39 | 37 |
40 int get hashCode => _hashCode(_map); | 38 int get hashCode => _hashCode(_map); |
41 | 39 |
42 bool operator ==(other) { | 40 bool operator ==(other) { |
43 if (other is! YamlMap) return false; | 41 if (other is! YamlMap) return false; |
44 return deepEquals(this, other); | 42 return deepEquals(this, other); |
45 } | 43 } |
46 | 44 |
47 /** Wraps an object for use as a key in the map. */ | 45 /// Wraps an object for use as a key in the map. |
48 _wrapKey(obj) { | 46 _wrapKey(obj) { |
49 if (obj != null && obj is! bool && obj is! List && | 47 if (obj != null && obj is! bool && obj is! List && |
50 (obj is! double || !obj.isNan()) && | 48 (obj is! double || !obj.isNan()) && |
51 (obj is! Map || obj is YamlMap)) { | 49 (obj is! Map || obj is YamlMap)) { |
52 return obj; | 50 return obj; |
53 } else if (obj is Map) { | 51 } else if (obj is Map) { |
54 return new YamlMap._wrap(obj); | 52 return new YamlMap._wrap(obj); |
55 } | 53 } |
56 return new _WrappedHashKey(obj); | 54 return new _WrappedHashKey(obj); |
57 } | 55 } |
58 | 56 |
59 /** Unwraps an object that was used as a key in the map. */ | 57 /// Unwraps an object that was used as a key in the map. |
60 _unwrapKey(obj) => obj is _WrappedHashKey ? obj.value : obj; | 58 _unwrapKey(obj) => obj is _WrappedHashKey ? obj.value : obj; |
61 } | 59 } |
62 | 60 |
63 /** | 61 /// A class for wrapping normally-unhashable objects that are being used as keys |
64 * A class for wrapping normally-unhashable objects that are being used as keys | 62 /// in a YamlMap. |
65 * in a YamlMap. | |
66 */ | |
67 class _WrappedHashKey { | 63 class _WrappedHashKey { |
68 var value; | 64 var value; |
69 | 65 |
70 _WrappedHashKey(this.value); | 66 _WrappedHashKey(this.value); |
71 | 67 |
72 int get hashCode => _hashCode(value); | 68 int get hashCode => _hashCode(value); |
73 | 69 |
74 String toString() => value.toString(); | 70 String toString() => value.toString(); |
75 | 71 |
76 /** This is defined as both values being structurally equal. */ | 72 /// This is defined as both values being structurally equal. |
77 bool operator ==(other) { | 73 bool operator ==(other) { |
78 if (other is! _WrappedHashKey) return false; | 74 if (other is! _WrappedHashKey) return false; |
79 return deepEquals(this.value, other.value); | 75 return deepEquals(this.value, other.value); |
80 } | 76 } |
81 } | 77 } |
82 | 78 |
83 /** | 79 /// Returns the hash code for [obj]. This includes null, true, false, maps, and |
84 * Returns the hash code for [obj]. This includes null, true, false, maps, and | 80 /// lists. Also handles self-referential structures. |
85 * lists. Also handles self-referential structures. | |
86 */ | |
87 int _hashCode(obj, [List parents]) { | 81 int _hashCode(obj, [List parents]) { |
88 if (parents == null) { | 82 if (parents == null) { |
89 parents = []; | 83 parents = []; |
90 } else if (parents.some((p) => identical(p, obj))) { | 84 } else if (parents.some((p) => identical(p, obj))) { |
91 return -1; | 85 return -1; |
92 } | 86 } |
93 | 87 |
94 parents.add(obj); | 88 parents.add(obj); |
95 try { | 89 try { |
96 if (obj == null) return 0; | 90 if (obj == null) return 0; |
97 if (obj == true) return 1; | 91 if (obj == true) return 1; |
98 if (obj == false) return 2; | 92 if (obj == false) return 2; |
99 if (obj is Map) { | 93 if (obj is Map) { |
100 return _hashCode(obj.keys, parents) ^ | 94 return _hashCode(obj.keys, parents) ^ |
101 _hashCode(obj.values, parents); | 95 _hashCode(obj.values, parents); |
102 } | 96 } |
103 if (obj is List) { | 97 if (obj is List) { |
104 // This is probably a really bad hash function, but presumably we'll get t
his | 98 // This is probably a really bad hash function, but presumably we'll get |
105 // in the standard library before it actually matters. | 99 // this in the standard library before it actually matters. |
106 int hash = 0; | 100 int hash = 0; |
107 for (var e in obj) { | 101 for (var e in obj) { |
108 hash ^= _hashCode(e, parents); | 102 hash ^= _hashCode(e, parents); |
109 } | 103 } |
110 return hash; | 104 return hash; |
111 } | 105 } |
112 return obj.hashCode; | 106 return obj.hashCode; |
113 } finally { | 107 } finally { |
114 parents.removeLast(); | 108 parents.removeLast(); |
115 } | 109 } |
116 } | 110 } |
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