1 files changed, 77 insertions, 67 deletions

diff --git a/util/set.lua b/util/set.lua
index fa065a9c..c136a522 100644
--- a/util/set.lua
+++ b/util/set.lua
@@ -1,7 +1,7 @@
 -- 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.
 --
@@ -10,86 +10,49 @@ local ipairs, pairs, setmetatable, next, tostring =
       ipairs, pairs, setmetatable, next, tostring;
 local t_concat = table.concat;
 
-module "set"
+local _ENV = nil;
 
 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 = _M.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)
-	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 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 items;
+		return next, items;
 	end
-	
+
 	function set:remove(item)
 		items[item] = nil;
 	end
-	
-	function set:add_list(list)
-		if list then
-			for _, item in ipairs(list) do
+
+	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;
@@ -101,22 +64,22 @@ function new(list)
 			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
 
-function union(set1, set2)
+local function union(set1, set2)
 	local set = new();
 	local items = set._items;
-	
+
 	for item in pairs(set1._items) do
 		items[item] = true;
 	end
@@ -124,14 +87,14 @@ function union(set1, set2)
 	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] = (not set2._items[item]) or nil;
 	end
@@ -139,21 +102,68 @@ function difference(set1, set2)
 	return set;
 end
 
-function intersection(set1, set2)
+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
 
-function xor(set1, set2)
+local function xor(set1, set2)
 	return union(set1, set2) - intersection(set1, set2);
 end
 
-return _M;
+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;
+};