Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/prelude/Monad/MapAndUnzipM.hs
module Monad where mapAndUnzipM :: (Monad m) => (a -> m (b,c)) -> [a] -> m ([b], [c]) mapAndUnzipM f xs = sequence (map f xs) >>= return . unzip
