Programming (and thinking) the functional way | Pedro Alvarez-Tabio

As a complete beginner with Haskell [1], I got immediately interested with it the time I saw the very elegant example of quicksort. Here it is: quicksort :: Ord a => [a] -> [a] quicksort [] = [] quicksort (p:xs) = (quicksort lesser) ++ [p] ++ (quicksort greater) where lesser = filter (< p) xs greater = filter (>= p) xs I was perplex. How could such a simple and beautiful thing be correct? Yes, I k