Right. See also this discussion:
http://www.haskell.org/pipermail/libraries/2009-July/012106.html
Roman
* Tom Ellis
On Tue, Apr 16, 2013 at 01:53:19PM +0100, Oliver Charles wrote:
You could do:
runKleisli . mconcat . map Kleisli :: Monoid (Kleisli m a b) => [a -> m b] -> a -> m b
Would that work for you? I can't find an instance for Monoid (Kleisli m a b) in `base`, so
On 04/16/2013 01:47 PM, Lyndon Maydwell wrote: presumably the author would also have to write this instance? If so - would that really be any different to using that fold?
It doesn't make sense anyway. It would have to be "Kleisli m a a" which would presumably require a newtype.
Tom
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