diff options
| -rw-r--r-- | util/set.lua | 58 |
1 files changed, 54 insertions, 4 deletions
diff --git a/util/set.lua b/util/set.lua index f550a721..892f1c9d 100644 --- a/util/set.lua +++ b/util/set.lua @@ -1,10 +1,60 @@ -local ipairs, pairs = - ipairs, pairs; +local ipairs, pairs, setmetatable, next, tostring = + ipairs, pairs, setmetatable, next, tostring; +local t_concat = table.concat; module "set" +local set_mt = {}; +function set_mt.__call(set, _, k) + return next(set._items, k); +end +function set_mt.__add(set1, set2) + return _M.union(set1, set2); +end +function set_mt.__sub(set1, set2) + return _M.difference(set1, set2); +end +function set_mt.__div(set, func) + local new_set, new_items = _M.new(); + local items, new_items = set._items, new_set._items; + for item in pairs(items) do + if func(item) then + new_items[item] = true; + end + end + return new_set; +end +function set_mt.__eq(set1, set2) + local set1, set2 = set1._items, set2._items; + for item in pairs(set1) do + if not set2[item] then + return false; + end + end + + for item in pairs(set2) do + if not set1[item] then + return false; + end + end + + return true; +end +function set_mt.__tostring(set) + local s, items = { }, set._items; + for item in pairs(items) do + s[#s+1] = tostring(item); + end + return t_concat(s, ", "); +end + +local items_mt = {}; +function items_mt.__call(items, _, k) + return next(items, k); +end + function new(list) - local items = {}; + local items = setmetatable({}, items_mt); local set = { _items = items }; function set:add(item) @@ -45,7 +95,7 @@ function new(list) set:add_list(list); end - return set; + return setmetatable(set, set_mt); end function union(set1, set2) |