Updated C Mathematical Expression Parser

I've updated and posted my recursive descent mathematical expression parsing code.  The new code is available from my Github repository:

https://github.com/jamesgregson/expression_parser

The original post describing the library is at: http://jamesgregson.blogspot.ca/2012/06/mathematical-expression-parser-in-c.html

New features include Boolean operations and a callback interface for custom named variables and functions.  You can optionally disable the Boolean operations (and the 10 levels of parsing they trigger) if not needed.