Hi all,

I'm practising my Haskell by writing a simple TCP echo server and finding that getting my program control to be succinct is rather tricky. In particular, I have return () everywhere, my error handling is verbose and I'm not entirely sure my recursion is the cleanest way syntactically to get my loops going and terminating.

I must be doing something obviously un-Haskell-like.

Any suggestions on how I can improve my code? Code below.

Cheers,

-John

import Control.Concurrent

import Control.Exception
import Control.Monad

import Network
import System.IO

import System.IO.Error (isEOFError)

main = withSocketsDo $ do
sListen <- listenOn (PortNumber 8000)

putStrLn "Listening on Port 8000"
forkIO $ forever $ do

(sSession, hostname, port) <- accept sListen
putStrLn ("Connected to " ++ hostname ++ ":" ++ (show port))

let processLine = forkIO $ do
lineResult <- try (hGetLine sSession)

case lineResult of
Right line -> do

putStrLn line
processLine

return ()
Left e ->

if isEOFError e
then putStrLn (show e)

else do
ioError e

return ()
return ()

processLine
return()
line <- getLine

return ()