Re: Integers and Mathematical Correctness

["chris.danx" <chris.danx@ntlworld.com>]

> >To most this may seem insignificant but I'm more mathematically minded
and I
> >just found something out.  Many programming languages don't implement
> >division properly!
>
> >For example -3/2 should be -2 not -1, with a remainder 1 not -1.
>
> Yes, the history of this goes back a long way, to ALGOL 60. The Europeans
> (who were all mathematicians) were happy to define division for Reals and
> were not particularly interested in integers. The Americans (who were all
> programmers) saw a need for it, so the Europeans just said "OK, how do you
> want to define it", and the Americans responded with the "obvious" and ONE
> TRUE (i.e. FORTRAN) WAY.
>
> Then, of course, hardware got to be built the "wrong" way. In every
> subsequent programming language (ALGOL 68, Pascal, Ada) the language
> designers knew perfectly well that they were designing it wrong, but dared
> not make the change.

> I railed against this in 1983, and that is more or
> less what I was told :-( .

Interesting.

We only learned that in programming languages (and primary school),
technically division is incorrect the other day, and I was a bitty
surprised.  I don't really mind that it's "wrong", the package is just being
written as a little distraction.  I may never need it, but it's there if I
do.

Anyone wants it, let me know and I'll send it to you when I'm done.


Bye,
Chris