forcing IO operations
Andre W B Furtado
Thu, 21 Feb 2002 01:18:21 -0300
> > >liftIOtoMyMonad_ :: IO () -> MyMonad ()
> > >liftIOtoMyMonad_ m = liftIOtoMyMonad' (const m) ()
> I'm having problems compiling this one: "The last statement in a 'do'
> construct must be an expression"
The problem is not related with liftIOtoMyMonad_ , but with liftIOtoMyMonad
and liftIOtoMyMonad'. I think its an identation problem. Re-writing these
funcions as follows solves the problem:
>liftIOtoMyMonad' :: (a -> IO ()) -> a -> MyMonad ()
>liftIOtoMyMonad' p q =
> StateMonad $ \s -> (do p q
> return ((),s))
>liftIOtoMyMonad :: IO a -> MyMonad a
>liftIOtoMyMonad p =
> StateMonad $ \s -> (do y <- p
> return (y,s))
At least by now, all the ideas are working very well... great help Jay,
thanks a lot!