You haven't really said what happens when you try this, but I would bet that things would be clarified greatly if you put type signatures on your two definitions.
On Fri, Apr 3, 2009 at 12:49 PM, Michael Roth <mr...@nessie.de> wrote: > Hello list, > > maybe I'm just stupid, I'm trying to do something like this: > > > import Control.Monad > import Control.Monad.Trans > import Control.Monad.List > > foobar = do > a <- [1,2,3] > b <- [4,5,6] > liftIO $ putStrLn $ (show a) ++ " " ++ (show b) > return (a+b) > > main = do > sums <- foobar > print sums > > > But this apparently doesn't work... I'm total clueless how > to achieve the correct solution. Maybe my mental image > on the monad transformer thing is totally wrong? > > > Michael > _______________________________________________ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe >
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