mod_adhoc: Add support for commands only executable by global administrators

[prosody.git] / util / set.lua

diff --git a/util/set.lua b/util/set.lua
index f550a721c1cb297cf037ff70a1f92f4c0796b6a4..e4cc2dffbd428b6be84c2ec749ba0cd2156b67b3 100644 (file)
--- a/util/set.lua
+++ b/util/set.lua
@@ -1,10 +1,68 @@
-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.
+--
+
+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)
@@ -41,11 +99,15 @@ function new(list)
                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)
@@ -87,4 +149,8 @@ function intersection(set1, set2)
        return set;
 end
 
+function xor(set1, set2)
+       return union(set1, set2) - intersection(set1, set2);
+end
+
 return _M;