Kapitel 1: Haskell in einer Nußschale

hugs Start
ghc Start.lhs

> import Prelude hiding ( succ )

> date                          :: (Int, String, Int)
> date                          =  (18, "April", 1996)

> succ                          :: Int -> Int
> succ n                        =  n + 1

> twice				:: (a -> a) -> a -> a
> twice f a                     =  f (f a)

Beispielausdrücke:

twice succ 0
twice twice succ 0
twice twice twice succ 0

> main				:: IO ()
> main                          =  print (twice twice succ 0)