[Caml-list] Integer arithmetic: mod

["Kai Kaminski" <kok@wtal.de>]

Hi,

I have a question regarding the 'mod' operator in OCaml. While playing
around with the toplevel, I found that

-1 mod 10 = -1 instead of -1 mod 10 = 9.

Looking into the Handbook showed me, that the behaviour of 'mod' is
platform dependent for negative arguments.
Now, I could live with -1 mod 10 = -1, but why is it platform-dependent?
As far as I can see it would be better to specify a certain behaviour
and emulate it on platforms, where it is not directly supported by the
cpu, especially for a high-level language as OCaml.
The reason is that whenever such a behaviour is platform-dependent, you
can't use it at all, as long as you want to have your programs portable.
Beside that the speed penalty (are there other problems with this
approach?) would probably be not too bad, would it?

On the other hand I'm just a student, who doesn't know too much about
programming languages and their implementation. So could someone please
enlighten me?

Kai Kaminski
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