[Python-Dev] Re: PEP239 (Rational Numbers) Reference Implementation and new issues (original) (raw)

David Abrahams David Abrahams" <david.abrahams@rcn.com
Thu, 3 Oct 2002 11:58:27 -0400

From: "Andrew Koenig" <ark@research.att.com>

Oren> On Thu, Oct 03, 2002 at 09:05:03AM -0400, Andrew Koenig wrote: Oren> Any calculation involving a floating point number should taint Oren> the result with inexactitude and yield a floating point result. >> >> Even comparisons?

Oren> Comparisons could produce a third boolean value called 'Undetermined':

It turns out that once you allow ternary logic there are too many reasonable meanings for the comparison operators. We had this long discussion around the Boost interval library. Eventually Douglas Gregor came up with a solution which seemed to satisfy everyone. I can't find it now but if anyone's interested I'll ask him to summarize the issues and solution.

       David Abrahams * Boost Consulting

dave@boost-consulting.com * http://www.boost-consulting.com