On Sun, Oct 12, 2008 at 06:08:22PM +0100, Andrew Coppin wrote: > Now I'm trying to run two computations, starting from _the same state_, > and combine the two resulting lists. The trouble is, I am literally > losing the will to live trying to comprehend the whinings of the type > checker. The operation I'm trying to perform is perfectly simple; I > don't understand why this has to be so damned *difficult*! >_<
It's not difficult: the operation is called mplus :: MyMonad a -> MyMonad a -> MyMonad a and already exists (assuming the author of ListT has not forgotten to write a MonadPlus instance). Regards, Reid Barton _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
