Re: libevaluator library and GSL

[Brian Gough <bjg at network-theory dot co dot uk>]

Aleksandar B. Samardzic writes:
 > I've written a library
 > (http://savannah.nongnu.org/projects/libevaluator/) that makes possible
 > to parse strings representing mathematical functions over single or
 > multiple variables and later to evaluate these functions for different
 > variable values (also to create representation of function derivative
 > over specified variable etc.).  I've submitted this library for
 > evaluation regarding inclusion in GNU project and was told by my
 > evaluator that they would rather like to see my library as part of GSL
 > than to publish it as separate library.  My library is written in C, but
 > offers also Fortran 77 and Gule interfaces (as well as Fortran 90
 > interface). 

Hello,

Thanks for your email.  I've had a look at your package from CVS.
Here are my comments, which you may pass on to the GNU evaluator.

The question of having an expression parser in GSL came up once
before.

My opinion was that a library to do this could be useful in many
C programs, including those which do not require anything else in
GSL.

Having a standalone evaluator package, with minimal dependencies,
that is very easy for people to integrate into their program
could be a good strategy for encouraging people to use the GPL
for their software -- in the same way that the Readline library
does.

If the evaluator is part of GSL then it reduces the effectiveness
of this approach, because GSL is so big (probably much larger
than the application the evaluator would be used in) and could
not be distributed with the program very easily.

So, I would recommend having a single standalone library under
the GPL, standardising on ANSI C expressions, and having no
external dependencies (except for the standard c library), to
maximise the potential userbase.

best regards

-- 
Brian Gough
(GSL Maintainer)