[Haskell-cafe] (liftM join .) . mapM

[Lutz Donnerhacke]

* Tony Morris wrote:
> Can (liftM join .) . mapM be improved?
> (Monad m) => (a -> m [b]) -> [a] -> m [b]

a) liftM concat . mapM  -- list handling . monad handling
b) (sequence .) . map   -- monad handling . list handling