develooper Front page | perl.perl6.language | Postings from October 2001

Re: NaN semantics

Thread Previous | Thread Next
RaFaL Pocztarski
October 8, 2001 11:03
Re: NaN semantics
Message ID:
Dan Sugalski wrote:

> At 09:07 AM 10/8/2001 +1000, Damian Conway wrote:
> >I see your (and others') point here, but I view NaN as a *marker* indicating
> >a non-numeric result. Markers should always compare equal to themselves.
> >(Frankly, *everything* should compare equal to itself -- which is where
> >IEEE 754 goes horribly wrong.)
> FWIW, I've always viewed NaN as equivalent to SQL's NULL, and treated it as
> such. (Of course, proper support for either would require me to build in
> three-value logic to Parrot, and I'm not sure I'm willing to go quite that
> far... :)

Well, I was hoping that three-value logic will be supported by Parrot
(at least I hope it will be still supported by Perl, but without support
in Parrot it surely won't be so easy and efficient). It's a superset of
Boolean logic so it doesn't collide with any strict Boolean arithmetic.

Maybe it would be possible to define what kind of logic the user wants?
Boolean, three-value, fuzzy logic - that would be very nice. In a
similar way you define meaning of other things in Parrot to match
different languages. What do you think about that?

- RaFaL Pocztarski,

Thread Previous | Thread Next Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at | Group listing | About