2 -- Copyright (C) 2008-2010 Matthew Wild
3 -- Copyright (C) 2008-2010 Waqas Hussain
5 -- This project is MIT/X11 licensed. Please see the
6 -- COPYING file in the source package for more information.
9 local ipairs, pairs, setmetatable, next, tostring =
10 ipairs, pairs, setmetatable, next, tostring;
11 local t_concat = table.concat;
16 function set_mt.__call(set, _, k)
17 return next(set._items, k);
21 function items_mt.__call(items, _, k)
22 return next(items, k);
25 local function new(list)
26 local items = setmetatable({}, items_mt);
27 local set = { _items = items };
29 -- We access the set through an upvalue in these methods, so ignore 'self' being unused
30 --luacheck: ignore 212/self
32 function set:add(item)
36 function set:contains(item)
44 function set:remove(item)
48 function set:add_list(item_list)
50 for _, item in ipairs(item_list) do
56 function set:include(otherset)
57 for item in otherset do
62 function set:exclude(otherset)
63 for item in otherset do
69 return not next(items);
76 return setmetatable(set, set_mt);
79 local function union(set1, set2)
81 local items = set._items;
83 for item in pairs(set1._items) do
87 for item in pairs(set2._items) do
94 local function difference(set1, set2)
96 local items = set._items;
98 for item in pairs(set1._items) do
99 items[item] = (not set2._items[item]) or nil;
105 local function intersection(set1, set2)
107 local items = set._items;
109 set1, set2 = set1._items, set2._items;
111 for item in pairs(set1) do
112 items[item] = (not not set2[item]) or nil;
118 local function xor(set1, set2)
119 return union(set1, set2) - intersection(set1, set2);
122 function set_mt.__add(set1, set2)
123 return union(set1, set2);
125 function set_mt.__sub(set1, set2)
126 return difference(set1, set2);
128 function set_mt.__div(set, func)
129 local new_set = new();
130 local items, new_items = set._items, new_set._items;
131 for item in pairs(items) do
132 local new_item = func(item);
133 if new_item ~= nil then
134 new_items[new_item] = true;
139 function set_mt.__eq(set1, set2)
140 set1, set2 = set1._items, set2._items;
141 for item in pairs(set1) do
142 if not set2[item] then
147 for item in pairs(set2) do
148 if not set1[item] then
155 function set_mt.__tostring(set)
156 local s, items = { }, set._items;
157 for item in pairs(items) do
158 s[#s+1] = tostring(item);
160 return t_concat(s, ", ");
166 difference = difference;
167 intersection = intersection;