--- /dev/null
+## Copyright (C) 2009 VZLU Prague, a.s., Czech Republic
+##
+## 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 3 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, see <http://www.gnu.org/licenses/>.
+
+## -*- texinfo -*-
+## @deftypefn{Function File} {} join (d1, d2, joinop)
+## Merges two given dictionaries. For common keys, the function @var{joinop} is
+## called to combine the two values. If not supplied, values from d2 are taken.
+## @end deftypefn
+
+## Author: Jaroslav Hajek <highegg@gmail.com>
+
+function d = join (d1, d2, jop)
+ if (nargin < 2 || nargin > 3 || ! (isa (d1, "dict") && isa (d2, "dict")))
+ print_usage ();
+ endif
+
+ keys1 = d1.keys;
+ keys2 = d2.keys;
+
+ [keys, idx] = sort ([keys1; keys2]);
+ values = [d1.values; d2.values](idx);
+ n = numel (keys);
+
+ if (n > 1)
+ idx = find (strcmp (keys(1:n-1), keys(2:n)));
+ keys(idx) = [];
+ if (nargin == 3)
+ values(idx+1) = cellfun (jop, values(idx), values(idx+1), "UniformOutput", false);
+ endif
+ values(idx) = [];
+ endif
+
+ d = dict;
+ d.keys = keys;
+ d.values = values;
+
+endfunction
+