This is at least documented in the manual ( http://caml.inria.fr/pub/docs/manual-ocaml/libref/Pervasives.html ):
> Note that x mod y is negative only if x < 0.

I suppose the idea was to make the least surprising choice (assuming people knew , and also have the behavior coincide with mod_float. (Interestingly, the IEEE754 norm requires a "remainder" operation that has an even stranger behavior (modulo is defined from the round-to-nearest division) and I haven't proposed anywhere.)

On Sun, Jan 18, 2015 at 7:48 PM, Hannes Mehnert <hannes@mehnert.org> wrote:

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Hi,

is the behaviour of modulo arithmetics intentional:
-5 mod 4 = -1 ?

While this reflects the C behaviour, my expectation was to always have
a positive result:
-5 mod 4 = 3

Any hints?

hannes
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