On Wed, Feb 27, 2008 at 4:31 PM, Peter Bex <[EMAIL PROTECTED]> wrote: > On Wed, Feb 27, 2008 at 04:23:37PM -0500, Graham Fawcett wrote: > > > Can you even check for void? Afaik there's no VOID? procedure. > > > > You can; just compare with another (void) value: > > > > (define void? (cute eq? (void) <>)) > > That sounds rather brittle. Afaik "void" is defined as "no value".
(void) returns the unspecified value, in Chicken, #<unspecified> -- as does (values). But the unspecified value is a value, and can be tested for identity with eq?. > (eq? (values) (values)) is #t, but I'm not sure how safe it is to > depend on that. Especially since VOID is some kind of "undefined" > value, nobody says this representation can't change. I don't think > you should depend on this implementation detail. It's an implementation detail of Chicken, but it is highly unlikely that it will change. Void is nebulous as a concept, but its Chicken implementation is concrete. Graham _______________________________________________ Chicken-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/chicken-users
