On 2/14/06, Ben Rudiak-Gould <Benjamin.Rudiak-Gould@cl.cam.ac.uk> wrote:
I just realized that the class Ord should have an additional method:
class Eq a => Ord a where compares :: a -> a -> Ordering -> Ordering compares x y d = case compare x y of { EQ -> d ; o -> o } ...
This would make writing Ord instances much easier:
instance (Ord a, Ord b, Ord c, Ord d) => Ord (a,b,c,d) where compares (a1,b1,c1,d1) (a2,b2,c2,d2) = compares a1 a2 . compares b1 b2 . compares c1 c2 . compares d1 d2
I think you meant compare d1 d2 for that last one. Would there be any advantage to this being a member of Ord instead of just a function in the prelude? /g -- We have lingered in the chambers of the sea By sea-girls wreathed with seaweed red and brown Till human voices wake us, and we drown.