Proof of concept dynamic FFI

[Kjetil S. Matheussen]

Jon Wilson:
> Hi,
> I've written a bit of code that lets you call any function from a
> dynamically loaded shared lib with any args.  Well, actually, since it
> is just a proof of concept, it only lets you call functions that take
> zero or one args.  The arg (if there is one) must be of type int.  The
> return type can be either void or int.
>
> If you want to play, you can get the code by
> bzr branch http://bzr.wilsonjc.us/foreign/
> or by just grabbing the files from that URL manually.  The README
> contains brief instructions on how to try it out.
>
> If I'm just reinventing the wheel, or if you can think of a better way
> to do it, or if you just think I look funny, let me know.
> Regards,
> Jon Wilson


With guile, I usually prefer writing c-code using s-expressions:


(load "eval-c.scm")

(eval-c ""
        (public
         (<void> hello-world (lambda ()
                               (printf (string "hello world\\n"))))))

(hello-world)
=> hello-world


(eval-c ""
        (public
         (<int> add-ints (lambda ((<int> a)(<int> b))
                           (return (+ a b))))))
(add-ints 2 3)
=> 5


etc.


http://snd.cvs.sourceforge.net/snd/cvs-snd/eval-c.scm