-- ALFL: A Lazy Functional Language (Hudak, Yale 1984)
-- Example: Higher-order list functions

map f [] = []
map f (x:xs) = f x : map f xs

filter p [] = []
filter p (x:xs) = if p x then x : filter p xs
                         else filter p xs

foldr f z [] = z
foldr f z (x:xs) = f x (foldr f z xs)

sum xs = foldr (+) 0 xs

squares = map (\x -> x * x) [1..10]

main = sum squares