From: Jeff Pennal
Subject: C interface for LISP
Date: 
Message-ID: <621c31$bcj$1@brie.direct.ca>
Hi all, 

I am looking for a way to run LISP code from a C program. Is this possible? If 
so how is it done? I have looked all over the net but I have not had any luck 
in finding a solution. I am using Allegro CL and MS Visual C++.

Thanks for your time,
Jeff
From: Howard R. Stearns
Subject: Re: C interface for LISP
Date: 
Message-ID: <3444DD46.2781E494@elwood.com>
Jeff Pennal wrote:
> 
> Hi all,
> 
> I am looking for a way to run LISP code from a C program. Is this possible? If
> so how is it done? I have looked all over the net but I have not had any luck
> in finding a solution. I am using Allegro CL and MS Visual C++.
> 
> Thanks for your time,
> Jeff

Check out http://www.elwood.com/eclipse-info/index.htm

Eclipse...
- provides all of ANSI Common Lisp as a combinatin of C functions and 
  other C utilities that can be used from arbitrary C programs.
- links all these with a simple main() into an executable, so you get a 
  complete Common Lisp top-level implementation along with the library.
- has a COMPILE-FILE that produces readable C code from Lisp source, 
  where this generated code can be linked with the library and arbitrary 
  C programs.   The generated C code is in the same style as the rest of 
  the library, so one can think of compile-file as a means of extending 
  the primitives in the library with your own Lisp code.

There are other systems you can use, too.  Some other non-commerical
Lisp systems generate (usually non-readable/non-maintainable) C code
that can be linked with arbitrary C code.  Most other commercial systems
allow you to load most compiled C code into a running Lisp system, and
allow the Lisp functions to call C functins, and sometimes vice versa.
Some things to watch out for is whether these other systems allow you to
define a main() in C, what restrictions there are on passing data
between Lisp and C, restictions on calling Lisp code, interference
between loaded code and system code, etc.  Check the FAQ: 
 ftp://ftp.cs.cmu.edu/user/ai/lang/lisp/faq/0.html