Re: Behaviour of div & mod with negative arguments?

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