Dot operator in haskell with multi-parameter functions

Question

I want to write a function point-free in haskell, to keep things simple lets say I want to make this function:

maxmin :: Ord a => a -> a -> a ->          


        

Answer 1

You just use the "three laws of sections" for that,

(a `op` b) = (a `op`) b = (`op` b) a = op a b

so that

import Control.Arrow

maxmin a b = (max a) . (min b)
           = (.) (max a) (min b)
           = uncurry (.) (max a, min b)
           = uncurry (.) . (max *** min) $ (a, b)
           = curry (uncurry (.) . (max *** min)) a b

which is not too readable either. :)