f :: Ord a => [a] -> [a]
f x = reverse x

h :: Ord a => [a] -> [a]
h x = tail x

g :: Ord a => ([a] -> [a]) -> [a] -> IO ()
g x y = putStrLn . show $ x y

main :: IO ()
main = mapM_ (\(i, j) ->
  case i of
    0 -> g (j :: [Int] -> [Int]) [1..5]
    1 -> g (j :: [Char] -> [Char]) "hello"
  ) [(0,f), (1, h)]