C's 'mod' isn't really mod.  It's actually remainder.  It's always been this
way to my knowledge.

If you want a real "mod" use Python or Ada :)

Dave

On 12/15/05, Jack Johnson <knapjack@gmail.com> wrote:
>
> Not really, but all the talk about Singularity got me poking around
> and I came across this:
>
> ------
>
> How are the functions DIV and MOD defined?
>
> The following answers are given by the Internal Working Document on
> the Common Language Infrastructure (CLI).
>
> result = value1 DIV value2 satisfies the following conditions:
> |result| = |value1| / |value2|, and
> sign(result) = +, if sign(value1) = sign(value2)
> sign(result) = - , if sign(value1) # sign(value2)
>
> result  = value1 MOD value2 satisfies the following conditions:
> result = value1 - value2 * (value1 DIV value2), and
> 0 <= |result| < |value2|, and
> sign(result) = sign(value1)
>
> Please note that this definition of DIV and MOD differs from the
> definition given in [M. Reiser, N. Wirth. Programming in Oberon. p.
> 36]:
> x  = (x DIV y) * y + (x MOD y), and
> 0 <= (x MOD y) < y
>
> ( from http://www.bluebottle.ethz.ch/oberon.net/faq.html#ad_DivMod )
>
> ------
>
> I kind of collect random, older computer science texts, so I cracked
> open The Nature of Computation by Pohl and Shaw, which yields:
>
>   "x MOD y = x - (x ÷ y) * y, where ÷ indicates integer division (i.e.
> fractions are disregarded; equivalently, the result of the division is
> truncated)."
>
> So, what *is* -5 MOD 3?
>
> -Jack
>