Re: [Jscheme-user] Question about exact numbers

[Ken A. <kan...@bb...>]

At 08:07 PM 5/30/2002, Nathaniel Titterton wrote:

>Thanks Ken.  I don't know if I will ever get used to (/ 5 2) equaling 2,
>though.  Thats what quotient is for!  It may be one of those areas where
>java and lisp/scheme are at cultural odds...


Yes, it is. I just tried the two common lisps on may machine and (/ 1 2) 
returned 1/2 in both.  In fact, (/ 1 2) might be the simplest test to see 
if you are programming in a green pasture, or in the big city.

>-nate
>
>   =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
>   Nathaniel Titterton                        na...@so...
>   CITRIS PostDoc       341 Soda Hall, U.C. Berkeley, Berkeley, CA 94720
>
>On Thu, 30 May 2002, Ken Anderson wrote:
>
> > At 06:40 PM 5/30/2002, Nathaniel Titterton wrote:
> >
> > >(I've posted this on the open discussion on the sourceforge site, but read
> > >that I should try here as well).
> > >
> > >I was playing with a random number generator, and was surpised to find
> > >that in JScheme
> > >
> > >(/ 1 2)
> > >
> > >was returning 0. If jscheme doesn't have exact rational numbers (I'm
> > >assuming it doesn't), wouldn't it make more sense to return 0.5 instead?
> > >An implemenation is free to silently do this, it says in R4RS.
> >
> > We did this in an earlier version of Jscheme, then called Silk.
> > We now adapt Java's arithmetic model so (/ 1 2) is 0
> > and (/ 1 2.0) is 0.5.
> >
> > Section 6.5.3 of R4RS gives some leeway in how numbers are implemented.
> >
> > >-nate
> > >
> > >   =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> > >   Nathaniel Titterton                        na...@so...
> > >   CITRIS PostDoc       341 Soda Hall, U.C. Berkeley, Berkeley, CA 94720
> > >
> > >
> > >_______________________________________________________________
> > >
> > >Don't miss the 2002 Sprint PCS Application Developer's Conference
> > >August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm
> > >
> > >_______________________________________________
> > >Jscheme-user mailing list
> > >Jsc...@li...
> > >https://lists.sourceforge.net/lists/listinfo/jscheme-user
> >
> >
> > _______________________________________________________________
> >
> > Don't miss the 2002 Sprint PCS Application Developer's Conference
> > August 25-28 in Las Vegas -- http://devcon.sprintpcs.com/adp/index.cfm
> >
> > _______________________________________________
> > Jscheme-user mailing list
> > Jsc...@li...
> > https://lists.sourceforge.net/lists/listinfo/jscheme-user
> >