Re: Zeller's Algorithm

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Hyman Rosen <hyrosen@mail.com> writes:

> Robert A Duff wrote:
>  > to claim it's not a flaw seems wrong.
> 
> I didn't claim it's not a flaw, I just claimed that it wasn't
> totally useless.

Fair enough.  How about, "nigh unto useless"?  ;-)

That is, we haven't seen any examples that take advantage of the
well-defined relationship between % and / without also knowing the
rounding behavior.

>... In any case, every machine I ever worked on
> has used round towards zero, but as you go on to say, when I
> use %, I tend to make sure that the arguments are not negative.

And I guess it implies that (in practise, for me), Ada's "mod" and
"rem", and C's "%" are all equivalent: don't use them on negative
numbers.  At least, that's true when *writing* code.  When *reading*
code, I must think to myself, "prove it's nonnnegative, or else go look
it up."

- Bob