Q: Feature Wish: "%" Extension
Tim Peters
tim.one at home.com
Sun Nov 4 16:00:02 EST 2001
[Paul Rubin]
> Knuth says to use floor_mod? Where?
Knuth *defines* x mod y as being x - y * floor(x/y), way back in volume 1.
It simply has the nicest properties when x and y are ints and y > 0.
> Every CPU that I know of uses trunc_mod (your 1st variant).
A great many CPUs have no "mod" instruction at all; most with an integer
division instruction truncate, possibly due to an unfortunate feedback loop
involving early Fortran <0.7 wink>.
> Floor_mod makes more sense for a lot of things. I can't help
> thinking there must be a reason for all the implementations
> using trunc_mod, but I don't know what it might be.
Why do almost all PC keyboards have a giant CAP LOCKS key where the CTRL key
ought to be? It's not really because they wanted to trick Sun keyboard
users (or, at least, I hope not <wink>).
traditionally y'rs - tim
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