X-Git-Url: https://git.enpas.org/?a=blobdiff_plain;f=util%2Fset.lua;h=c136a522d3a272e1b7a08ec851708ad539a3ad89;hb=c4e5c21a7cb6a4082ac4e15079f021fed4c928c0;hp=67f3dcaabfb37bd445bf99b85bb41b24cc2d095c;hpb=cbaa12fe71fafacc60596ba6fe21f54267ca525a;p=prosody.git

diff --git a/util/set.lua b/util/set.lua
index 67f3dcaa..c136a522 100644
--- a/util/set.lua
+++ b/util/set.lua
@@ -1,81 +1,169 @@
-local ipairs, pairs = 
-      ipairs, pairs;
+-- 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.
+--
 
-module "set"
+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 new(list)
-	local items = {};
-	local set = { items = items };
-	
 	function set:add(item)
 		items[item] = true;
 	end
-	
+
 	function set:contains(item)
 		return items[item];
 	end
-	
+
 	function set:items()
-		return items;
+		return next, items;
 	end
-	
+
 	function set:remove(item)
 		items[item] = nil;
 	end
-	
-	function set:add_list(list)
-		for _, item in ipairs(list) do
-			items[item] = true;
+
+	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 pairs(otherset) do
+		for item in otherset do
 			items[item] = true;
 		end
 	end
 
 	function set:exclude(otherset)
-		for item in pairs(otherset) do
+		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 set;
+
+	return setmetatable(set, set_mt);
 end
 
-function union(set1, set2)
+local function union(set1, set2)
 	local set = new();
-	local items = set.items;
-	
-	for item in pairs(set1.items) do
+	local items = set._items;
+
+	for item in pairs(set1._items) do
 		items[item] = true;
 	end
 
-	for item in pairs(set2.items) do
+	for item in pairs(set2._items) do
 		items[item] = true;
 	end
-	
+
 	return set;
 end
 
-function difference(set1, set2)
+local function difference(set1, set2)
 	local set = new();
-	local items = set.items;
-	
-	for item in pairs(set1.items) do
-		items[item] = true;
+	local items = set._items;
+
+	for item in pairs(set1._items) do
+		items[item] = (not set2._items[item]) or nil;
 	end
 
-	for item in pairs(set2.items) do
-		items[item] = nil;
+	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
 
-return _M;
+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;
+};