Max Vasin wrote:
Pupeno wrote:
What about this
runDaytimeServer :: DaytimeServer -> IO DaytimeServer runDaytimeServer dts = do dts' <- runStreamDaytimeServer dts dts' <- runDgramDaytimeServer dts' return dts'
runDaytimeServer dts = runStreamDaytimeServer dts >>= runDgramDaytimeServer
I have seen this pattern many times, and I am surprised it is not present in Control.Monad. (>>-) :: (a -> m b) -> (b -> m c) -> a -> m c (>>-) f g a = f a >>= g Your code becomes runDaytimeServer = runStreamDaytimeServer >>- runDgramDaytimeServer This >>- operator is a very natural "composition" operator in a Monad, at least to me. It seems to be the most obvious counter-part to '.'. But I could not find anything with that signature in the libraries -- or did I miss it? [And >>- is typographically sub-optimal, but I can't think of something better]. Jacques