Re: [Haskell-cafe] Parsec monad transformer with IO?

Stefan Klinger writes:

Hello!

Nice, Parsec 3 comes with a monad transformer [1]. So I thought I could use IO as inner monad, and perform IO operations during parsing.

But I failed. Monad transformers still bend my mind. My problem: I don't see a function to actually lift the IO operation into the ParsecT. It should be something like

lift :: IO a -> ParsecT s u IO a

ParsecT has a MonadIO instance: class Monad m => MonadIO m where liftIO :: IO a -> m a G -- Gregory Collins