Ray Dillinger scripsit: > For what it's worth, I consider it worthwhile to have a limited range > of exact ratios, where the results of (/) on exact arguments are exact > if both numerator and denominator are within a bounded integer range > and inexact otherwise.
Technically, systems without ratios already do this, but the denominator is limited to 1. > This provides "opportunistic" preservation of exactness where you could > not ordinarily specify it due to the possibility of representation > explosion. It's an interesting idea, but AFAIK no Schemes provide it, so it is not ripe for standardization. > Type theorists objecting that they need to be able to statically > determine the type of an operation without referent to the values > of the arguments will object to the exact/inexact conversion implicit > in bounded ratios. We already have such things with EXPT. > It is also important to programs to know whether exact and inexact > numbers are interconvertible without changing numeric value. IE, > whether the system supports the same precision in inexact numbers > as exact numbers. I don't know any systems that do this: it would require very artificial restrictions on ratios to make them match IEEE flonums. -- "Repeat this until 'update-mounts -v' shows no updates. John Cowan You may well have to log in to particular machines, hunt down [email protected] people who still have processes running, and kill them." www.ccil.org/~cowan _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
