I believe that Robby is referring to IEEE 754's rules about NaN, which does not order NaN unless you use the special total order predicate, which is not typically used in PLs. I think that most Racket users would want < to be what the hardware does, modulo conversions, rather than an ordering unique to Racket.
Jay On Tue, Nov 24, 2015 at 12:56 PM, 'John Clements' via dev-redirect <[email protected]> wrote: > >> On Nov 24, 2015, at 4:39 AM, Robby Findler <[email protected]> >> wrote: >> >> Unfortunately, nan is defined to not be less than or greater than any >> number and sorting works only when you supply a transitive predicate >> and it seems difficult to change either of these things. > > In my mind, the alternative would be to signal an error; I’m having a very > hard time imagining the programmer who would be legitimately unhappy about > getting an error here. Or perhaps the concern is adding time to inner inner > inner loops? > > John > >> >> Robby >> >> >> On Sat, Nov 21, 2015 at 3:10 AM, 'John Clements' via dev-redirect >> <[email protected]> wrote: >>> Currently, a +nan.0 does an interesting thing to sorting: >>> >>> #lang racket >>> >>> (sort '(1 3 5 +nan.0 2 4 6) >) >>> >>> yields >>> >>> '(5 3 1 +nan.0 6 4 2) >>> >>> Is this the answer we want? >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Racket Developers" group. >>> To unsubscribe from this group and stop receiving emails from it, send an >>> email to [email protected]. >>> To post to this group, send email to [email protected]. >>> To view this discussion on the web visit >>> https://groups.google.com/d/msgid/racket-dev/675231ca-96b0-4039-94e4-7a744278c586%40mtasv.net. >>> For more options, visit https://groups.google.com/d/optout. >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Racket Developers" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> To post to this group, send email to [email protected]. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/racket-dev/CAL3TdOM3%3D%2BTJGkAZFKAagfN5OiekC8c%2BtNpmt%3DrQZJS8ovtWHA%40mail.gmail.com. >> For more options, visit https://groups.google.com/d/optout. > > > > -- > You received this message because you are subscribed to the Google Groups > "Racket Developers" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/racket-dev/a8b0aa6e-8994-4885-8b5d-c945c0162376%40mtasv.net. > For more options, visit https://groups.google.com/d/optout. -- Jay McCarthy Associate Professor PLT @ CS @ UMass Lowell http://jeapostrophe.github.io "Wherefore, be not weary in well-doing, for ye are laying the foundation of a great work. And out of small things proceedeth that which is great." - D&C 64:33 -- You received this message because you are subscribed to the Google Groups "Racket Developers" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/racket-dev/CAJYbDam0Npou23r%3DhA%3Do95%2BkFvTtOOiqBUHe17UhCafmpJCt6Q%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.
