| | 1 | namespace Cobra.Core |
| | 2 | class DefaultDictionary<of TKey, TValue> inherits Dictionary<of TKey, TValue> |
| | 3 | """ |
| | 4 | A child class of dictionary. When retrieving a value from the dictionary, |
| | 5 | if the key is not present, a value generated by defaultFactory will be returned. |
| | 6 | If .willRecordDefaults is set to 'true' (the default value), then the returned |
| | 7 | value will also be inserted into the dictionary. |
| | 8 | """ |
| | 9 | cue init(defaultFactory as Func<of TValue>) |
| | 10 | base.init |
| | 11 | _defaultFactory = defaultFactory |
| | 12 | |
| | 13 | cue init(dict as IDictionary<of TKey, TValue>, defaultFactory as Func<of TValue>) |
| | 14 | base.init(dict) |
| | 15 | _defaultFactory = defaultFactory |
| | 16 | |
| | 17 | cue init(comparer as IEqualityComparer<of TKey>, defaultFactory as Func<of TValue>) |
| | 18 | base.init(comparer) |
| | 19 | _defaultFactory = defaultFactory |
| | 20 | |
| | 21 | cue init(capacity as int, defaultFactory as Func<of TValue>) |
| | 22 | base.init(capacity) |
| | 23 | _defaultFactory = defaultFactory |
| | 24 | |
| | 25 | cue init(dict as IDictionary<of TKey, TValue>, |
| | 26 | comparer as IEqualityComparer<of TKey>, |
| | 27 | defaultFactory as Func<of TValue>) |
| | 28 | base.init(dict, comparer) |
| | 29 | _defaultFactory = defaultFactory |
| | 30 | |
| | 31 | cue init(capacity as int, comparer as IEqualityComparer<of TKey>, defaultFactory as Func<of TValue>) |
| | 32 | base.init(capacity, comparer) |
| | 33 | _defaultFactory = defaultFactory |
| | 34 | |
| | 35 | var _defaultFactory as Func<of TValue> |
| | 36 | |
| | 37 | var _willRecordDefaults = true |
| | 38 | |
| | 39 | pro defaultFactory from var |
| | 40 | |
| | 41 | pro willRecordDefaults from var |
| | 42 | |
| | 43 | pro [key as TKey] as TValue is new |
| | 44 | get |
| | 45 | val as TValue |
| | 46 | if base.tryGetValue(key, out val), return val |
| | 47 | val = _defaultFactory() |
| | 48 | if .willRecordDefaults, base[key] = val |
| | 49 | return val |
| | 50 | set |
| | 51 | base[key] = value |
| | 52 | |
| | 53 | def tryGetValue(key as TKey?, val as out TValue?) as bool is new |
| | 54 | require key |
| | 55 | val = this[key to !] |
| | 56 | return true |
| | 57 | |
| | 58 | class TestDefaultDictionary |
| | 59 | """ |
| | 60 | Examples taken from |
| | 61 | from http://docs.python.org/library/collections.html#collections.DefaultDictionary.default_factory |
| | 62 | |
| | 63 | The typing of Pair detracts from the example a little bit, but DefaultDictionary is useful |
| | 64 | if you need to make a dictionary of counters or lists. |
| | 65 | """ |
| | 66 | |
| | 67 | test countOccurances |
| | 68 | #Count occurance of each letter in 'mississippi' |
| | 69 | s = 'mississippi' |
| | 70 | dd = DefaultDictionary<of char, int>(do = 0) |
| | 71 | for k in s, dd[k] += 1 |
| | 72 | |
| | 73 | expected = [Pair<of char, int>(c'i', 4), |
| | 74 | Pair<of char, int>(c'p', 2), |
| | 75 | Pair<of char, int>(c's', 4), |
| | 76 | Pair<of char, int>(c'm', 1)] |
| | 77 | for key, val in dd |
| | 78 | assert expected.contains(Pair<of char, int>(key, val)) |
| | 79 | |
| | 80 | test dictionaryOfLists |
| | 81 | # make a dictionary of lists |
| | 82 | lst = [Pair<of String, int>('yellow', 1), |
| | 83 | Pair<of String, int>('blue', 2), |
| | 84 | Pair<of String, int>('yellow', 3), |
| | 85 | Pair<of String, int>('blue', 4), |
| | 86 | Pair<of String, int>('red', 1)] |
| | 87 | |
| | 88 | dd = DefaultDictionary<of String, IList<of int>>(do = List<of int>()) |
| | 89 | for k, v in lst, dd[k].add(v) |
| | 90 | |
| | 91 | expected = [ Pair<of String, List<of int>>('blue', [2, 4]), |
| | 92 | Pair<of String, List<of int>>('red', [1]), |
| | 93 | Pair<of String, List<of int>>('yellow', [1, 3])] |
| | 94 | for key, val in dd |
| | 95 | assert expected.contains(Pair<of String, List<of int>>(key, val)) |
| | 96 | |
| | 97 | test tryGetValue |
| | 98 | dd = DefaultDictionary<of int, int>(do = 5) |
| | 99 | ans as int |
| | 100 | res = dd.tryGetValue(10, out ans) |
| | 101 | assert res |
| | 102 | assert ans == 5 |
| | 103 | dd[6] = 4 |
| | 104 | res = dd.tryGetValue(6, out ans) |
| | 105 | assert res |
| | 106 | assert ans == 4 |
| | 107 | |
| | 108 | test willRecordDefaults |
| | 109 | factory as Func<of int> = do = 5 |
| | 110 | dd = DefaultDictionary<of int, int>(factory, willRecordDefaults = false) |
| | 111 | assert dd[6] == 5 |
| | 112 | assert not dd.containsKey(6) |
| | 113 | |
| | 114 | |
| | 115 | def main |
| | 116 | pass |
