Recusions in Haskell

recursions.hs

maximum' :: (Ord a) => [a] -> a
maximum' []  = error "maximum of empty list"
maximum' [x] = x
maximum' (x:xs)
    | x > maxTail = x
    | otherwise   = maxTail
    where maxTail = maximum' xs
    
-- using max 
-- maximum' (x:xs) = max x (maximum' xs)

replicate' :: (Num i, Ord i) => i -> a -> [a]
replicate' n x
    | n <= 0    = []
    | otherwise = x:replicate' (n-1) x 
    
take' :: (Num i, Ord i) => i -> [a] -> [a]
take' n _
    | n <= 0   = []
take' _ []     = []
take' n (x:xs) = x : take' (n-1) xs

reverse' :: [a] -> [a]
reverse' []     = []
reverse' (x:xs) = reverse' xs ++ [x]