animatedlew

-- Haskell will match starting at the top, until it hits a catchall
factorial :: Int -> Int
factorial 0 = 1
factorial n = n *  factorial(n - 1)

-- Haskell is able to match empty lists and x:xs patterns
head' :: [a] -> a
head' [] =  error "No head available on empty lists!"
head' (x:_) = x