{-- Example program for combining Io, Gui and Db functionality
    in one program.
                                                            --}
module Main
where

import MonadT
import Io
import Gui
import Db 


{- set up application monad instance: -}

-- not really needed here:
instance Gui m => Gui (DB m) where
    gui = mapLift gui

instance Db m => Db (GUI m) where
    db = mapLift db

-- the monad to be used at top level:
type M a = DB (GUI IO) a

startM :: M () -> IO ()
startM = start . start

-- test program:

main :: IO ()
main = startM prog

prog :: (Db m, Gui m, Io m) => m ()
prog = do
       putStrC "Hello "
       dbExampleOp "World"
       putStrC "\nHello "
       guiExampleOp 2001