Daniel,
Sure. If you don't mind that the mutations come in a different order, one thing that works wonders is "sequence",
sequence :: Monad m => [m a] -> m [a]
In particular, for m = [], sequence :: [[a]] -> [[a]]. Then, knowing what sequence does, we can write
import Control.Monad (sequence)
generateAll :: String -> [String] generateAll word = sequence (map f word) where f c = case lookup c leat of Just r -> [c,r] Nothing -> [c]
That's very nice! One question though: In the docs sequence is described as: "Evaluate each action in the sequence from left to right, and collect the results." How is one supposed to deduce what the behavior will be for the list monad (besides looking at the source)? Patrick -- ===================== Patrick LeBoutillier Rosemère, Québec, Canada