Cheers,
Alex

Pierre LINDENBAUM <Pierre.Lindenbaum@univ-nantes.fr> writes:

> Hi all,
>
> (cross posted on SO: https://stackoverflow.com/questions/47797521 )
>
>
> I've defined a guile C function:
>
>     static SCM myfun(SCM arg1,SCM opt_arg2)
>       {
>       return SCM_BOOL_T;
>       }
>
> registered with
>
>     scm_c_define_gsubr ("myfun", 1, 1, 0, myfun);
>
> there is one optional argument. How can I detect if opt_arg2 has been
> used ?
>
> in
>
>     (myfun 1)
>
> or
>
>     (myfun 1 2)
>
>
> Thanks !