structure UpdateThread =
struct
  open CML
  open MailboxType

  fun sendMsg (msg, drawMailbox) =
    case msg of DRAW msg => Mailbox.send (drawMailbox, msg)

  fun sendMsgs (msgList, drawMailbox) =
    case msgList of
      hd :: tl =>
        let val _ = sendMsg (hd, drawMailbox)
        in sendMsgs (tl, drawMailbox)
        end
    | [] => ()

  fun loop (app: AppType.app_type, inputMailbox, drawMailbox) =
    let
      val inputMsg = Mailbox.recv inputMailbox
      val (app, msgList) = AppUpdate.update (app, inputMsg)
      val _ = sendMsgs (msgList, drawMailbox)
    in
      loop (app, inputMailbox, drawMailbox)
    end
end