[Haskell-cafe] is there already a function that does this?

-- Sort the [a]'s by the [b]'s. sortByKeys :: (Ord b) => [b] -> [a] -> [a] sortByKeys keys values = map snd $ sortBy compareFst (zip keys values) where compareFst x y = compare (fst x) (fst y) -- Sort a list by an IO-returning compare function. sortByM :: (Monad m, Ord b) => (a -> m b) -> [a] -> m [a] sortByM fun lis = mapM fun lis >>= \keys -> return $ sortByKeys keys lis Is there a function that can make sortByM out of sortByKeys? I don't know of one, but having been writing haskell for a few weeks, it sort of smells to me like there probably is one.