Kapitel 6: Programmiertechniken

hugs LazyEval
ghc -c LazyEval.lhs

> module LazyEval
> where

< iterate                       :: (a -> a) -> a -> [a]
< takeWhile                     :: (a -> Bool) -> [a] -> [a]

> group				:: Int -> [a] -> [[a]]
> group n                       =  iterate   (drop n)
>                               #  takeWhile (not . null)
>                               #  map       (take n)

> (#)				:: (a -> b) -> (b -> c) -> (a -> c)
> f # g                         =  g . f