Simple Haskell IRC client in "two lines of code"

IRCtransient.hs

import           Transient.Base
import           Network
import           System.IO
import           Control.Monad.IO.Class
import           Control.Applicative

-- taken from  Pipes example 
-- https://www.reddit.com/r/haskell/comments/2jvc78/simple_haskell_irc_client_in_two_lines_of_code/?st=iqj5yxg1&sh=0cb8cc11
-- Simple Haskell IRC client in "two lines of code" 
--
--main = withSocketsDo $ connect "irc.freenode.net" "6667" $ \(s, _) ->
--    forkIO (runEffect $ PBS.stdin >-> toSocket s) >> runEffect (fromSocket s 4096 >-> PBS.stdout)


main = do
    h <- withSocketsDo $ connectTo "irc.freenode.net" $ PortNumber $ fromIntegral 6667
    keep' $ (waitEvents getLine >>= liftIO . hPutStrLn h) <|> (waitEvents (hGetLine h) >>= liftIO . putStrLn )

Better add threads 1 to avoid mixing of messages in the console:

  keep' $ (waitEvents getLine >>= liftIO . hPutStrLn h) <|> (threads 1 $ waitEvents (hGetLine h) >>= liftIO . putStrLn )

Note that only keep', waitEvents and threads are primitives from transient. The rest are standard Haskell packages, primitives and combinators.

Transient is "non invasive". It add basic effect to the bottom of the hierarchy that are general purpose, like waitEvents (reactivity), in order to be used in very different scenarios.

Factorization of the second line:

keep' $ process socket stdout <|> process stdin socket
  where 
  process in out= threads 1 $ waitEvents in  >>= liftIO . hPutStrLn out