On Jan 13, 2008 3:41 PM, Leif Walsh <[EMAIL PROTECTED]> wrote: > I haven't been watching the python-dev list for very long, so maybe > this has already been discussed ad nauseam (in which case, sorry), > but, from the devil's advocate-ish mathematics side of things, unless > numbers.Decimal is planned to be implemented with infinite precision > (which I doubt, but could not confirm with an admittedly small amount > of research), shouldn't it implement numbers.Rational instead? Was > this ever discussed, or was it just assumed that numbers.Real was the > right decision?
Guido mentioned the possibility briefly at http://mail.python.org/pipermail/python-3000/2007-April/007015.html ("One could argue that float and Decimal are <:Q, but I'm not sure if that makes things better pragmatically") but never really discussed as far as I can find (although I did think about it :). I prefer having float not implement Rational (Decimal's off the table) because developers usually think of them as approximations to arbitrary, possibly-irrational, real numbers, rather than as rational numbers with some odd constraints on their denominators. That is, to me, the ABCs a type implements are more about how developers should think about the type than the implementation of the type. [ A new thread is probably appropriate if anyone wants to discuss the philosophy, but I probably won't participate... ] -- Namasté, Jeffrey Yasskin _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
