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);
19 function set_mt.__add(set1, set2)
20 return _M.union(set1, set2);
22 function set_mt.__sub(set1, set2)
23 return _M.difference(set1, set2);
25 function set_mt.__div(set, func)
26 local new_set = _M.new();
27 local items, new_items = set._items, new_set._items;
28 for item in pairs(items) do
29 local new_item = func(item);
30 if new_item ~= nil then
31 new_items[new_item] = true;
36 function set_mt.__eq(set1, set2)
37 local set1, set2 = set1._items, set2._items;
38 for item in pairs(set1) do
39 if not set2[item] then
44 for item in pairs(set2) do
45 if not set1[item] then
52 function set_mt.__tostring(set)
53 local s, items = { }, set._items;
54 for item in pairs(items) do
55 s[#s+1] = tostring(item);
57 return t_concat(s, ", ");
61 function items_mt.__call(items, _, k)
62 return next(items, k);
66 local items = setmetatable({}, items_mt);
67 local set = { _items = items };
69 function set:add(item)
73 function set:contains(item)
81 function set:remove(item)
85 function set:add_list(list)
87 for _, item in ipairs(list) do
93 function set:include(otherset)
94 for item in otherset do
99 function set:exclude(otherset)
100 for item in otherset do
106 return not next(items);
113 return setmetatable(set, set_mt);
116 function union(set1, set2)
118 local items = set._items;
120 for item in pairs(set1._items) do
124 for item in pairs(set2._items) do
131 function difference(set1, set2)
133 local items = set._items;
135 for item in pairs(set1._items) do
136 items[item] = (not set2._items[item]) or nil;
142 function intersection(set1, set2)
144 local items = set._items;
146 set1, set2 = set1._items, set2._items;
148 for item in pairs(set1) do
149 items[item] = (not not set2[item]) or nil;
155 function xor(set1, set2)
156 return union(set1, set2) - intersection(set1, set2);