[MATRIX-SIG] integer division -- what a concept!

Zane Motteler zcm@llnl.gov
Fri, 16 Jan 1998 14:14:32 -0800


You wrote

>Paul F. Dubois writes:
> > Another way to look at it is, suppose you saw:
> >
> > x = i / j
> >
> > Wouldn't you be surprised that the type of x depended on the data?
> >
>I really don't understand this comment.

I think I know what Paul was trying to say (I better, I've been
working for him for 12 years ;-).

If i and j are the same type, then the "principle of least surprise"
says that x should be of the same type as i and j. If they are of
different types, then the outcome of course depends on the rule
of coercion, but generally one would expect x to be of the same
type as either i or j. To me at least (and I've been in computing
for 41 years now) it seems counterintuitive that the result of an
operation would be of a different type than either operand.


                      Zane C. Motteler, Ph. D.
Computer Scientist             | Professor Emeritus of
Lawrence Livermore National    |    Computer Science and Engineering
   Laboratory                  | California Polytechnic
P. O. Box 808, L-472           |    State University
(7000 East Avenue, zip 94550)  | San Luis Obispo, CA 93407
Livermore, CA 94551-9900       | zmottel@phoenix.csc.calpoly.edu
510/423-2143, FAX 423-9969 (Area code 925 after March 14, 1998)

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