Listen

eigentlich:

data List a = Nil {}
    | Cons { head :: a, tail :: List a }

wegen früher häufiger Benutztung verkürzte Schreibweise: List a = [a], Nil = [], Cons = (:)

data [a] = [] 
         | (:) { head :: a, tail :: [a] }

Pattern matching für Listen:

append :: [a] -> [a] -> [a]
append a b = case a of
    []     -> b
    x : xs -> ...