On Fri, 23 Apr 2010, Anders Kaseorg wrote:
• What useful functions should be wrapped with it? Some candidates are catch, block, unblock (and friends from Control.Exception), forkIO, runInBoundThread, runInUnboundThread, unsafeInterleaveIO, withProgName, withArgs, alloca (and friends from Foreign.Marshal), withMVar, modifyMVar_, modifyMVar. Then of course there are all the functions that could be wrapped with liftIO…
On the other hand, most of the functions I listed could be easily wrapped by the user, given liftIO0 :: MonadMorphIO m => (forall b. IO b -> IO b) -> m a -> m a liftIO0 f m = morphIO $ \down -> f (down m) liftIO1 :: MonadMorphIO m => (forall b. (t -> IO b) -> IO b) -> (t -> m a) -> m a liftIO1 f g = morphIO $ \down -> f (down . g) Anders