Bas van Dijk wrote:
The following obviously doesn't work:import Control.Monad.Error inv :: MonadError e m => m a -> m () inv m = (m >> fail "") `catchError` \_ -> (return ())
What about this? inv :: MonadError e m => m a -> m () inv m = join $ (m >> return mzero) `catchError` \_ -> return (return ()) Tillmann _______________________________________________ Haskell-Cafe mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-cafe
