!import "prelude"   !Local
!import "io"        !Local
!import "socket"    !Local

-- Main accept+echo loop.  Recursion via y.
echoLoop = y (self : server :
  withAccepted_ server
    (err :
      bind (putStrLn (append "accept error: " err)) (_ :
        self server))
    (clientSock addr :
      bind (putStrLn (append "client from " addr)) (_ :
        onResult_ (recv clientSock 4096)
          (err :
            bind (closeSocket clientSock) (_ :
              self server))
          (msg :
            bind (send clientSock msg) (_ :
              bind (closeSocket clientSock) (_ :
                self server))))))

main = io (
  onOk_ socket (server :
    onOk_ (bindSocket server "127.0.0.1" 0) (_ :
      onOk_ (listen server 5) (_ :
        onOk_ (getSocketName server) (port :
          bind (putStrLn (append "Echo server listening on port " (showNumber port))) (_ :
            echoLoop server))))))