1 local ipairs, pairs, setmetatable, next, tostring =
2 ipairs, pairs, setmetatable, next, tostring;
3 local t_concat = table.concat;
8 function set_mt.__call(set, _, k)
9 return next(set._items, k);
11 function set_mt.__add(set1, set2)
12 return _M.union(set1, set2);
14 function set_mt.__sub(set1, set2)
15 return _M.difference(set1, set2);
17 function set_mt.__div(set, func)
18 local new_set, new_items = _M.new();
19 local items, new_items = set._items, new_set._items;
20 for item in pairs(items) do
22 new_items[item] = true;
27 function set_mt.__eq(set1, set2)
28 local set1, set2 = set1._items, set2._items;
29 for item in pairs(set1) do
30 if not set2[item] then
35 for item in pairs(set2) do
36 if not set1[item] then
43 function set_mt.__tostring(set)
44 local s, items = { }, set._items;
45 for item in pairs(items) do
46 s[#s+1] = tostring(item);
48 return t_concat(s, ", ");
52 function items_mt.__call(items, _, k)
53 return next(items, k);
57 local items = setmetatable({}, items_mt);
58 local set = { _items = items };
60 function set:add(item)
64 function set:contains(item)
72 function set:remove(item)
76 function set:add_list(list)
77 for _, item in ipairs(list) do
82 function set:include(otherset)
83 for item in pairs(otherset) do
88 function set:exclude(otherset)
89 for item in pairs(otherset) do
95 return not next(items);
102 return setmetatable(set, set_mt);
105 function union(set1, set2)
107 local items = set._items;
109 for item in pairs(set1._items) do
113 for item in pairs(set2._items) do
120 function difference(set1, set2)
122 local items = set._items;
124 for item in pairs(set1._items) do
125 items[item] = (not set2._items[item]) or nil;
131 function intersection(set1, set2)
133 local items = set._items;
135 set1, set2 = set1._items, set2._items;
137 for item in pairs(set1) do
138 items[item] = (not not set2[item]) or nil;
144 function xor(set1, set2)
145 return union(set1, set2) - intersection(set1, set2);