util.multitable - A table with multiple key for each entry

diff --git a/util/multitable.lua b/util/multitable.lua
new file mode 100644 (file)
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+++ b/util/multitable.lua
@@ -0,0 +1,84 @@
+-- Prosody IM v0.1
+-- Copyright (C) 2008 Matthew Wild
+-- Copyright (C) 2008 Waqas Hussain
+-- 
+-- This program is free software; you can redistribute it and/or
+-- modify it under the terms of the GNU General Public License
+-- as published by the Free Software Foundation; either version 2
+-- of the License, or (at your option) any later version.
+-- 
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+-- GNU General Public License for more details.
+-- 
+-- You should have received a copy of the GNU General Public License
+-- along with this program; if not, write to the Free Software
+-- Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+--
+
+
+
+local select = select;
+local t_insert = table.insert;
+local pairs = pairs;
+
+module "multitable"
+
+local function get(self, ...)
+       local t = self.data;
+       for n = 1,select('#', ...) do
+               t = t[select(n, ...)];
+               if not t then break; end
+       end
+       return t;
+end
+
+local function add(self, ...)
+       local t = self.data;
+       local count = select('#', ...);
+       for n = 1,count-1 do
+               local key = select(n, ...);
+               local tab = t[key];
+               if not tab then tab = {}; t[key] = tab; end
+               t = tab;
+       end
+       t_insert(t, select(count, ...));
+end
+
+local function r(t, n, _end, ...)
+       if t == nil then return; end
+       if n > _end then
+               for key in pairs(t) do
+                       t[key] = nil;
+               end
+       end
+       local k = select(n, ...);
+       if k then
+               r(t[k], n+1, _end, ...);
+       else
+               for _,b in pairs(t) do
+                       r(b, n+1, _end, ...);
+               end
+       end
+end
+
+local function remove(self, ...)
+       local _end = select('#', ...);
+       for n = _end,1 do
+               if select(n, ...) then _end = n; break; end
+       end
+       r(self.data, 1, _end, ...);
+end
+
+
+function new()
+       return {
+               data = {};
+               get = get;
+               add = add;
+               remove = remove;
+       };
+end
+
+return _M;