Behaviour of div & mod with negative arguments?

Lennart Augustsson lennart@augustsson.net
Wed, 25 Sep 2002 12:07:52 +0200


Dr Mark H Phillips wrote:

>Hi,
>
>Does Haskell specify how div and mod should behave when
>given one or both arguments negative?
>
Yes, section 6.4.2 gives an exact definition.

>P.S.  I notice in hugs if I type "-1 `div` 3" the `div`
>binds to the 1 and 3 first, and only applies the "-"
>at the end.  Is there a reason why the unary "-" has
>weak binding?
>
The rational is that unary `-' has the same precedence as binary `-'.
Personally, I think this is counter-intuitive to do it the way Haskell does.

    -- Lennart