import Monad
import System
import Control.Concurrent.HPL

data ServerMsg = Ping (Port ClientMsg)
	       deriving (Show, Read)
data ClientMsg = Pong String
	       deriving (Show, Read)

main :: IO ()
main  = do
  p <- newPort undefined
  "ping-pong" <<-> p
  reqs <- listenToPort p

  let pingServer []                     = return ()
      pingServer (Ping clientPort:reqs) = do
	name <- getEnv "HOST"
	clientPort <-- Pong name
	pingServer reqs

   pingServer reqs