[Haskell-cafe] Thinking about an unlistN

I wrote this function the other day, and I was wondering if I'm missing something.. whether there is already a function or idiom around to do this. unlist3 :: (a -> a -> a -> b) -> [a] -> b unlist3 f (x:y:z:xs) = f x y z I was also wondering whether the function can be generalized to N or whether this is just one of those edges in the type system that you can't abstract over. Thanks, Michael