bison-calc-ex: simple calculator example based on flex/bison.
Copyright (C) 2011  anton0xf <anton0xf@gmail.com>

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/>.

It use htable module from project CCAN (http://ccan.ozlabs.org/).

To build this:
1. get ccan and build it 
2. set CCAN_HOME environment variable 
3. enter 
    $ make
   for build calc executable, or
    $ make test
   for simple tests
    $ make prammar.png
   to get grammar parser automata graphic representation (require graphviz)