I would keep finite? for the semantics associated with the name even if it is just a renaming of rational?. Particularly since you can't just use (not (infinite? x)) when NaNs are a possibility. [I personally don't like using rational? for an abstraction that includes irrational numbers.] On Friday, November 18, 2011, Matthew Flatt <<a href="mailto:mflatt@cs.utah.edu">mflatt@cs.utah.edu</a>> wrote: > Except for `finite?' (which seems to be covered by `rational?'), these > additions sound fine to me. > > I'm not sure whether they should go in `racket/math' or `racket/base', > though. Although it feels wrong to keep adding to `racket/base', two > thoughts make me lean in that direction: > > * It will be confusing to have bindings such as > `exact-nonnegative-integer?' in `racket/base', while binding such as > `nonnegative-real?' are in `racket/math'. Putting all of those > functions in the same place seems more consistent. > > * Adding things to `racket/base' probably leads to fewer compatibility > issues. That's because `racket/math' could be explicitly imported > into a module that defines `nonnegative-real?', leading to an > import--definition conflict. If `racket/base' as a module language > provides nonnegative-real?', then a module's own definition of > `nonnegative-real?' can shadow it without conflict. > > At Fri, 18 Nov 2011 12:47:16 -0700, Ryan Culpepper wrote: >> On 11/18/2011 12:34 PM, Neil Toronto wrote: >> > On 11/18/2011 12:22 PM, Ryan Culpepper wrote: >> >> On 11/18/2011 12:13 PM, Neil Toronto wrote: >> >>> I've moved this to dev from a private discussion with Doug, who has just >> >>> tried the nightly build. >> >>> >> >>> On 11/18/2011 11:43 AM, Williams, Doug wrote: >> >>>> 2) The plot/utils has nan? and infinite?, which are also exported from >> >>>> the science collection and I had to explicitly exclude them in the >> >>>> require. Can we talk to the powers that be and see about getting them >> >>>> (and finite?) moved to racket/math? Then we can both remove them from >> >>>> our code. [I'm not sure about any interaction with the r6rs functions.] >> >>> >> >>> Powers That Be, Doug and I would like `nan?' and `infinite?' to be in >> >>> `racket/math'. >> >>> >> >>> I made an exact equivalent of Doug's `finite?', but called it >> >>> `regular-real?'. I use it in all kinds of function contracts (it returns >> >>> #f for non-reals). We would also like that one, with either name, in >> >>> `racket/math'. >> >> >> >> How does 'finite?' differ from 'rational?'? >> > >> > Whoa! It doesn't! >> > >> >> If we're making a wishlist, I'd really like >> >> '{positive,nonnegative}-{real,rational}?'. >> > >> > For use or for contracts? For contracts, we already have `>/c', `</c', >> > `>=/c' and `<=/c', which can do the same as `positive-real?', >> > `negative-real?', `nonnegative-real?' and `nonpositive-real?' if applied >> > to 0, and are arguably easier to read. >> >> I'd argue that they're less easy to read. Also, despite their >> availability, I've still seen contracts that say 'real?' even when they >> mean '(>=/c 0)', etc. (Or possibly 'nonnegative-rational?'.) >> >> > For the `*-rational?' ones, would they identify only exact rationals? >> > Because that would be inconsistent with `rational?'. >> >> No, they should be consistent with 'rational?' and accept inexacts. >> >> > If we *are* making a wishlist, I'd like to add exact-round, exact-floor, >> > exact-truncate and exact-ceiling. I rarely need to chop off fractional >> > parts without also making the result exact. >> >> +1 >> >> Ryan > > _________________________________________________ > For list-related administrative tasks: > <a href="http://lists.racket-lang.org/listinfo/dev">http://lists.racket-lang.org/listinfo/dev</a> >