On Tue, Aug 23, 2011 at 12:36:44PM +0100, Richard Shann wrote:
> I have defined a function with one needed and one optional arg, using
>
> scm_c_define_gsubr (name, 2, 0, 0, callback);
>
> in my function I need to test if the second argument is present, it
> looks like I need
>
> scm_defined_p(sym, env)
>
> but, if so, how do I find the value of env for the top-level
> environment?
Not shure I understand you here, Richard. Where would sym come from?
If your function looks like this:
(richards-function required-param an-optional-param)
thane your c function needs exactly two parameters:
ricks_c_func(SCM req, SCM opt) {
...
if (!SCM_UNBNDP (opt)) {
/* opt wasn't provided, so do something here */
}
...
}
Does that help?
Cheers, Ralf Mattes
> Richard Shann
>
>
