Chris Kuklewicz <haskell <at> list.mightyreason.com> writes: > Searching the haskell wiki for MonadIO gives several examples. > > http://haskell.org/haskellwiki/New_monads/MonadExit > > > instance MonadIO m => MonadIO (ExitT e m) where > > liftIO = lift . liftIO > > Where you can see you are just delegating the work of the transformer to the > underlying monad. Eventually it hits the bottom of the stack and sees: > > > instance MonadIO IO where > > liftIO = id >
Ah, so to combine my monad with IO i need to write a monad Transformer (TransactionT), then I can make it an instance of MonadIO? I found examples like the ones you gave but the whole transformer-part got me a bit confused. Sorry, should have spent some more time reading before asking. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
