I'm neutral to slightly negative on the proposal, but if one is going to put it forth, this is a pretty crippled version of what the combinator could be.

Switching liftM to fmap, and mapM to traverse gets you Applicative m.

There is no reason to limit this to Monad.

-Edward

On Fri, Feb 8, 2019 at 12:04 PM Carter Schonwald <carter.schonwald@gmail.com> wrote:

friend asked me to raise this

previously https://ghc.haskell.org/trac/ghc/ticket/2042
seems like it iddn't happen last time because base lived outside of ghc?
-- | The 'concatMapM' function generalizes 'concatMap' to arbitrary monads.
concatMapM        :: (Monad m) => (a -> m [b]) -> [a] -> m [b]
concatMapM f xs   =  liftM concat (mapM f xs)
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