[Haskell-cafe] Std lib equivalent for liftM concat . sequence

Alistair Bayley alistair at abayley.org
Fri May 16 06:12:45 EDT 2008

A couple of days ago I had need for:

> concatM :: Monad m => [m [a]] -> m [a]
> concatM = liftM concat . sequence

but found no such thing in the std libs, except perhaps for msum (I
don't want to add instances for MonadPlus. Should I have to?). Have I
missed something trivial?


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