3 Oct
2007
3 Oct
'07
7:05 p.m.
Here is a generalized version, using type classes and some extensions. Tiago, in order to compile this you'll have to use: -fglasgow-exts -fallow-undecidable-instances -fallow-overlapping-instances Cheers, Jorge. ------------- module Main where class Pipeline t1 t2 t3 | t1 t2 -> t3 where pipeline::t1 -> t2 -> t3 instance Pipeline t1 t2 t3 => Pipeline (a -> t1) t2 (a -> t3) where pipeline f g a = pipeline (f a) g -- same as: pipeline f g = \a -> pipeline (f a) g instance Pipeline (a -> b) (b -> c) (a -> c) where pipeline = flip (.) f a b c = even (a+b+c) h = pipeline f not main = do putStrLn . show $ h 1 2 3 ----------------