| 1 | | | import 'package:meta/meta.dart'; |
| 2 | | | |
| 3 | | | import '../typedefs.dart'; |
| 4 | | | |
| 5 | | | /// Wraps a `Map<dynamic, dynamic>` and a `Cast<V>` converter. Keys in the map |
| 6 | | | /// must be castable to [K] (`key as K`). Values in the map are converted to [V] |
| 7 | | | /// on demand i.e. when they are read by the program. Conversion occurs only |
| 8 | | | /// once for each value and the original `dynamic` value is replaced with the |
| 9 | | | /// conversion result. If some keys cannot be safely cast to [K], exceptions |
| 10 | | | /// might occur at runtime, e.g. when reading [keys] or [entries], or calling |
| 11 | | | /// [map]. |
| 12 | | | @internal |
| 13 | | | class LazyInPlaceMap<K, V> implements Map<K, V> { |
| 14 | | 1 | LazyInPlaceMap(this._data, this._vcast); |
| 15 | | | |
| 16 | | | final Map<dynamic, dynamic> _data; |
| 17 | | | final Cast<V> _vcast; |
| 18 | | | |
| 19 | | 1 | @override |
| 20 | | | Iterable<MapEntry<K, V>> get entries => |
| 21 | | 5 | keys.map((k) => MapEntry(k, _get(k) as V)); |
| 22 | | | |
| 23 | | 1 | @override |
| 24 | | 2 | bool get isEmpty => _data.isEmpty; |
| 25 | | | |
| 26 | | 1 | @override |
| 27 | | 2 | bool get isNotEmpty => _data.isNotEmpty; |
| 28 | | | |
| 29 | | 1 | @override |
| 30 | | 3 | Iterable<K> get keys => _data.keys.cast<K>(); |
| 31 | | | |
| 32 | | 1 | @override |
| 33 | | 2 | int get length => _data.length; |
| 34 | | | |
| 35 | | 1 | @override |
| 36 | | 5 | Iterable<V> get values => _data.keys.map((k) => _get(k) as V); |
| 37 | | | |
| 38 | | 1 | @override |
| 39 | | 1 | V? operator [](Object? key) => _get(key); |
| 40 | | | |
| 41 | | 1 | @override |
| 42 | | 2 | void operator []=(K key, V value) => _data[key] = value; |
| 43 | | | |
| 44 | | 1 | @override |
| 45 | | 2 | void addAll(Map<K, V> other) => _data.addAll(other); |
| 46 | | | |
| 47 | | 1 | @override |
| 48 | | | void addEntries(Iterable<MapEntry<K, V>> newEntries) => |
| 49 | | 2 | _data.addEntries(newEntries); |
| 50 | | | |
| 51 | | 1 | @override |
| 52 | | 2 | Map<RK, RV> cast<RK, RV>() => _forceCast().cast<RK, RV>(); |
| 53 | | | |
| 54 | | 1 | @override |
| 55 | | 2 | void clear() => _data.clear(); |
| 56 | | | |
| 57 | | 1 | @override |
| 58 | | 2 | bool containsKey(Object? key) => _data.containsKey(key); |
| 59 | | | |
| 60 | | 1 | @override |
| 61 | | 6 | bool containsValue(Object? value) => _data.keys.any((k) => value == _get(k)); |
| 62 | | | |
| 63 | | 1 | @override |
| 64 | | | void forEach(void Function(K key, V value) action) { |
| 65 | | 3 | for (var k in _data.keys) { |
| 66 | | 2 | action(k as K, _get(k) as V); |
| 67 | | | } |
| 68 | | | } |
| 69 | | | |
| 70 | | 1 | @override |
| 71 | | | Map<K2, V2> map<K2, V2>(MapEntry<K2, V2> Function(K key, V value) convert) { |
| 72 | | 4 | final r = <K2, V2>{}, keys = _data.keys.toList(); |
| 73 | | 4 | for (var i = keys.length - 1; i >= 0; i--) { |
| 74 | | 3 | final k = keys[i], e = convert(k as K, _get(k) as V); |
| 75 | | 3 | r[e.key] = e.value; |
| 76 | | | } |
| 77 | | | return r; |
| 78 | | | } |
| 79 | | | |
| 80 | | 1 | @override |
| 81 | | | V putIfAbsent(K key, V Function() ifAbsent) => |
| 82 | | 2 | _data.putIfAbsent(key, ifAbsent); |
| 83 | | | |
| 84 | | 1 | @override |
| 85 | | 2 | V? remove(Object? key) => _data.remove(key); |
| 86 | | | |
| 87 | | 1 | @override |
| 88 | | | void removeWhere(bool Function(K key, V value) test) { |
| 89 | | 3 | final keys = _data.keys.toList(); |
| 90 | | 4 | for (var i = keys.length - 1; i >= 0; i--) { |
| 91 | | 2 | final k = keys[i], v = _get(k); |
| 92 | | 1 | if (test(k as K, v as V)) { |
| 93 | | 2 | _data.remove(k); |
| 94 | | | } |
| 95 | | | } |
| 96 | | | } |
| 97 | | | |
| 98 | | 1 | @override |
| 99 | | | String toString() { |
| 100 | | 1 | _forceCast(); |
| 101 | | 2 | return _data.toString(); |
| 102 | | | } |
| 103 | | | |
| 104 | | 1 | @override |
| 105 | | | V update(K key, V Function(V value) update, {V Function()? ifAbsent}) => |
| 106 | | 4 | _data.update(key, (v) => (v != null && v is! V) ? _vcast(v) : v, |
| 107 | | | ifAbsent: ifAbsent); |
| 108 | | | |
| 109 | | 1 | @override |
| 110 | | | void updateAll(V Function(K key, V value) update) { |
| 111 | | 3 | final keys = _data.keys.toList(); |
| 112 | | 4 | for (var i = keys.length - 1; i >= 0; i--) { |
| 113 | | 2 | final k = keys[i], v = _get(k); |
| 114 | | 3 | _data[k] = update(k as K, v as V); |
| 115 | | | } |
| 116 | | | } |
| 117 | | | |
| 118 | | 1 | Map<dynamic, dynamic> _forceCast() { |
| 119 | | 3 | var keys = _data.keys.toList(); |
| 120 | | 4 | for (var i = keys.length - 1; i >= 0; i--) { |
| 121 | | 2 | _get(keys[i]); |
| 122 | | | } |
| 123 | | 1 | return _data; |
| 124 | | | } |
| 125 | | | |
| 126 | | 1 | V? _get(Object? key) { |
| 127 | | 2 | dynamic v = _data[key]; |
| 128 | | 1 | if (v != null && v is! V) { |
| 129 | | 2 | v = _vcast(v); |
| 130 | | 2 | _data[key] = v; |
| 131 | | | } |
| 132 | | | return v; |
| 133 | | | } |
| 134 | | | } |