Software /
code /
prosody
File
util/set.lua @ 12590:5eaf77114fdb
compat: Use table.pack (there since Lua 5.2) over our util.table
Added in d278a770eddc avoid having to deal with its absence in Lua 5.1.
No longer needed when Lua 5.1 support is dropped.
author | Kim Alvefur <zash@zash.se> |
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date | Mon, 11 Jul 2022 19:15:24 +0200 |
parent | 11788:1ceee8becb1a |
child | 12986:895a82c5d8d4 |
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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 getmetatable = getmetatable; local t_concat = table.concat; local _ENV = nil; -- luacheck: std none local set_mt = { __name = "set" }; 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 function set_mt:__freeze() local a, i = {}, 1; for item in self._items do a[i], i = item, i+1; end return a; end local function is_set(o) local mt = getmetatable(o); return mt == set_mt; 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:contains_set(other_set) for item in other_set do if not self:contains(item) then return false; end end return true; 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) if getmetatable(set1) ~= set_mt or getmetatable(set2) ~= set_mt then -- Lua 5.3+ calls this if both operands are tables, even if metatables differ return false; end 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; is_set = is_set; union = union; difference = difference; intersection = intersection; xor = xor; };