けさのHaskellの勉強はここまで #CodePiece

CodePiece.hs

replicate' :: Int -> a -> [a]
replicate' n x
   | n <= 0    = []
   | otherwise = x : (replicate' (n-1) x)

maximum' :: (Ord a) => [a] -> a
maximum' xs = case xs of [] -> error "maximum of empty list"
                         [x] -> x
                         (x:xs) -> max x (maximum' xs)

take' :: Int -> [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]

repeat' :: a -> [a]
repeat' x = [x] ++ repeat' x