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

[David Abrahams]

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