1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
--!A cross-platform build utility based on Lua
--
-- Licensed under the Apache License, Version 2.0 (the "License");
-- you may not use this file except in compliance with the License.
-- You may obtain a copy of the License at
--
-- http://www.apache.org/licenses/LICENSE-2.0
--
-- Unless required by applicable law or agreed to in writing, software
-- distributed under the License is distributed on an "AS IS" BASIS,
-- WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-- See the License for the specific language governing permissions and
-- limitations under the License.
--
-- Copyright (C) 2015-present, TBOOX Open Source Group.
--
-- @author OpportunityLiu
-- @file hashset.lua
--
-- define module
local hashset = hashset or {}
local hashset_impl = hashset.__index or {}
-- load modules
local table = require("base/table")
local todisplay = require("base/todisplay")
-- representaion for nil key
hashset._NIL = setmetatable({}, { __todisplay = function() return "${reset}${color.dump.keyword}nil${reset}" end, __tostring = function() return "symbol(nil)" end })
function hashset:__todisplay()
return string.format("hashset${reset}(%s) {%s}", todisplay(self._SIZE), table.concat(table.imap(table.keys(self._DATA), function (i, k)
if i > 10 then
return nil
elseif i == 10 and self._SIZE ~= 10 then
return "..."
else
return todisplay(k)
end
end), ", "))
end
function hashset._to_key(key)
if key == nil then
key = hashset._NIL
end
return key
end
-- make a new hashset
function hashset.new()
return setmetatable({ _DATA = {}, _SIZE = 0 }, hashset)
end
-- construct from list of items
function hashset.of(...)
local result = hashset.new()
local data = table.pack(...)
for i = 1, data.n do
result:insert(data[i])
end
return result
end
-- construct from an array
function hashset.from(array)
assert(array)
return hashset.of(table.unpack(array))
end
-- check value is in hashset
function hashset_impl:has(value)
value = hashset._to_key(value)
return self._DATA[value] or false
end
-- insert value to hashset, returns false if value has already in the hashset
function hashset_impl:insert(value)
value = hashset._to_key(value)
local result = not (self._DATA[value] or false)
if result then
self._DATA[value] = true
self._SIZE = self._SIZE + 1
end
return result
end
-- remove value from hashset, returns false if value is not in the hashset
function hashset_impl:remove(value)
value = hashset._to_key(value)
local result = self._DATA[value] or false
if result then
self._DATA[value] = nil
self._SIZE = self._SIZE - 1
end
return result
end
-- convert hashset to an array, nil in the set will be ignored
function hashset_impl:to_array()
local result = {}
for k, _ in pairs(self._DATA) do
if k ~= hashset._NIL then
table.insert(result, k)
end
end
return result
end
-- iterate keys of hashtable
-- for _, key in instance:keys() do ... end
function hashset_impl:keys()
return function (table, key)
local k, _ = next(table._DATA, key)
if k == hashset._NIL then
return k, nil
else
return k, k
end
end, self, nil
end
-- get size of hashset
function hashset_impl:size()
return self._SIZE
end
-- is empty?
function hashset_impl:empty()
return self:size() == 0
end
-- get data of hashset
function hashset_impl:data()
return self._DATA
end
-- clear hashset
function hashset_impl:clear()
self._DATA = {}
self._SIZE = 0
end
-- return module
hashset.__index = hashset_impl
return hashset
|
