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, new_items = _M.new();
27 local items, new_items = set._items, new_set._items;
28 for item in pairs(items) do
30 new_items[item] = true;
35 function set_mt.__eq(set1, set2)
36 local set1, set2 = set1._items, set2._items;
37 for item in pairs(set1) do
38 if not set2[item] then
43 for item in pairs(set2) do
44 if not set1[item] then
51 function set_mt.__tostring(set)
52 local s, items = { }, set._items;
53 for item in pairs(items) do
54 s[#s+1] = tostring(item);
56 return t_concat(s, ", ");
60 function items_mt.__call(items, _, k)
61 return next(items, k);
65 local items = setmetatable({}, items_mt);
66 local set = { _items = items };
68 function set:add(item)
72 function set:contains(item)
80 function set:remove(item)
84 function set:add_list(list)
85 for _, item in ipairs(list) do
90 function set:include(otherset)
91 for item in pairs(otherset) do
96 function set:exclude(otherset)
97 for item in pairs(otherset) do
103 return not next(items);
110 return setmetatable(set, set_mt);
113 function union(set1, set2)
115 local items = set._items;
117 for item in pairs(set1._items) do
121 for item in pairs(set2._items) do
128 function difference(set1, set2)
130 local items = set._items;
132 for item in pairs(set1._items) do
133 items[item] = (not set2._items[item]) or nil;
139 function intersection(set1, set2)
141 local items = set._items;
143 set1, set2 = set1._items, set2._items;
145 for item in pairs(set1) do
146 items[item] = (not not set2[item]) or nil;
152 function xor(set1, set2)
153 return union(set1, set2) - intersection(set1, set2);