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

[Peter Norvig]

I agree with pinard, although I think it is a manageable problem. I went 
through this transition once, from Symbolics Lisp, in which integer 
division truncates, to Common Lisp, in which it produces a rational. 
 After only an hour or two of fiddling with my various programs, 
everything seemed to work; I was very happy.  But after a few days, the 
machine started to slow down mysteriously, especially on wake-up.  It 
took a while to discover the culprit was my screensaver program (which I 
hadn't checked) -- it was displaying fish on the screen, and the 
coordinates of the fish had become rationals quotients of thousand-digit 
numbers.

-Peter

pinard@iro.umontreal.ca writes:
 > While I agree with the theoretical arguments, I have the practical 
fear that
 > rationals could grow very big, rather quickly, in the course of a long
 > computation involving them in various ways.  By big, I mean the numerator
 > and denominator of the fraction taken in isolation, not the number 
itself.