Software /
code /
prosody
File
util/set.lua @ 7331:c8ad387aab1c
mod_presence, mod_roster: Move responsibility for sending presence on roster removal to mod_presence
author | Kim Alvefur <zash@zash.se> |
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date | Mon, 04 Apr 2016 17:15:10 +0200 |
parent | 6777:5de6b93d0190 |
child | 8522:073e517a1487 |
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-- Prosody IM -- Copyright (C) 2008-2010 Matthew Wild -- Copyright (C) 2008-2010 Waqas Hussain -- -- This project is MIT/X11 licensed. Please see the -- COPYING file in the source package for more information. -- local ipairs, pairs, setmetatable, next, tostring = ipairs, pairs, setmetatable, next, tostring; local t_concat = table.concat; local _ENV = nil; local set_mt = {}; function set_mt.__call(set, _, k) return next(set._items, k); end local items_mt = {}; function items_mt.__call(items, _, k) return next(items, k); end local function new(list) local items = setmetatable({}, items_mt); local set = { _items = items }; -- We access the set through an upvalue in these methods, so ignore 'self' being unused --luacheck: ignore 212/self function set:add(item) items[item] = true; end function set:contains(item) return items[item]; end function set:items() return next, items; end function set:remove(item) items[item] = nil; end function set:add_list(item_list) if item_list then for _, item in ipairs(item_list) do items[item] = true; end end end function set:include(otherset) for item in otherset do items[item] = true; end end function set:exclude(otherset) for item in otherset do items[item] = nil; end end function set:empty() return not next(items); end if list then set:add_list(list); end return setmetatable(set, set_mt); end local function union(set1, set2) local set = new(); local items = set._items; for item in pairs(set1._items) do items[item] = true; end for item in pairs(set2._items) do items[item] = true; end return set; end local function difference(set1, set2) local set = new(); local items = set._items; for item in pairs(set1._items) do items[item] = (not set2._items[item]) or nil; end return set; end local function intersection(set1, set2) local set = new(); local items = set._items; set1, set2 = set1._items, set2._items; for item in pairs(set1) do items[item] = (not not set2[item]) or nil; end return set; end local function xor(set1, set2) return union(set1, set2) - intersection(set1, set2); end function set_mt.__add(set1, set2) return union(set1, set2); end function set_mt.__sub(set1, set2) return difference(set1, set2); end function set_mt.__div(set, func) local new_set = new(); local items, new_items = set._items, new_set._items; for item in pairs(items) do local new_item = func(item); if new_item ~= nil then new_items[new_item] = true; end end return new_set; end function set_mt.__eq(set1, set2) 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 return { new = new; union = union; difference = difference; intersection = intersection; xor = xor; };