Richard Shann <[email protected]> writes: > I didn't find the SCM_UNBNDP() that you mention but since mailing the > list I stumbled on SCM_UNDEFINED and tried > if(opt==SCM_UNDEFINED) ... > and that seems to work. > IIRC, that this works is not actually guaranteed (it depends on the type of the SCM values; that type might not have defined/reasonable behavior wrt. the "==" operator, so the right way to write the above comparison would be `scm_is_eq(opt, SCM_UNDEFINED)', and incidentially, this is how SCM_UNBNDP() is defined (see libguile/tags.h, at least on Guile 2.0).
> So (unless I am doing something bad) I think I am back on course - > thanks! > The idiom you used may work for you now, but may be broken at any time, or even when compiling Guile with a different configuration (search for SCM_DEBUG_TYPING_STRICTNESS in libguile/tags.h for illustration). HTH, Rotty PS: Please consider avoiding top-posts (see for instance <http://www.usenet-replayer.com/faq/alt.games.generals.html> for a rationale). -- Andreas Rottmann -- <http://rotty.yi.org/>
