agent_monad.hs

-- I finally got sick of reading books on Maybe and IO monads!
-- I spyed beyond that there must be mooarrr!

import Control.Monad.Identity

agent :: (Num a) => a -> Identity a
agent n = do
    return n >>= (\n -> Identity (n * 2))

main :: IO ()
main = do
    let x = 7
    putStrLn ("My double identity is " ++ show(runIdentity (agent x)) ++ "!")