Bjorn Bringert said:
Or why not the two characters shorter, but much less readable:
pointsFreeCat' = getArgs >>= mapM_ ((>>= putStr) . readFile)
or maybe:
pointsFreeCat'' = getArgs >>= mapM_ (putStr >>. readFile)
(>>.) :: (b -> IO c) -> (a -> IO b) -> a -> IO c (>>.) = (.) . flip (>>=)
Is (>>.) in the standard libs? If not, should it be? I'm sure there is a shorter definition of (>>.) that I haven't thought of.
/Bjorn
Or even: k :: Monad m => (a -> m b) -> Kleisli m a b k = Kleisli runKleisli :: Monad m => Kleisli m a b -> (a -> m b) runKleisli (Kleisli f) = f cat :: IO () cat = getArgs >>= (runKleisli $ (k $ mapM readFile) >>> (k $ mapM_ putStr)) after noticing that (>>.) is pretty similar to (<<<) when we lift (a -> IO b) to (Kleisli IO a b). It is pretty disappointing that runKleisli isn't defined so that I can be cool and completely point free too ;) /Andreas -- some cannot be created more equal than others