Re: [Chicken-users] c-callbacks

[Robin Lee Powell]

On Fri, Aug 17, 2007 at 10:34:46PM +0200, Bastian Müller wrote:
> 
> Finally, I tried to do the actual call.
> First, I tried:
>   (ode-space-collide space (null-pointer) foobar)
> and during the simulation I got an
>   Error: bad argument count - received -2 but expected 3: error in  
> error
>   graphics.scm: 76   ode-space-collide    <--

So you'll want #f instead of (null-pointer), and you'll want
(location foobar), and foobar needs to be define-external *in the
file you set the callback from*.

The "bad argument count" thing is exactly what happens when you
don't use (location func) for setting up a callback; it happened to
me a bunch whilst making cluck.

-Robin

-- 
http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/
Reason #237 To Learn Lojban: "Homonyms: Their Grate!"
Proud Supporter of the Singularity Institute - http://singinst.org/