Re: [Haskell-cafe] Seeking help to generalize this ..

I finally ended up defining a combinator flattenAndCompose :: (Category cat) => [cat a a] -> cat a a flattenAndCompose = foldr (>>>) id that can be used both for function composition and Kleislis since both (->) and Kleisli are instances of Category. I will take a look at Endo - thanks for the pointer .. regards. On Fri, Feb 7, 2020 at 11:26 PM Matthew Farkas-Dyck wrote:

On 2/1/20, Jack Kelly wrote:

...

In Data.Monoid there is the 'Endo' newtype, which wraps functions of type 'a -> a'. Is there an 'EndoM' variant, or is that something that's usually created by putting other pieces together? Below is a sketch of what I mean:

-- Maybe this is known by another name? newtype EndoM f a = EndoM { appEndoM :: a -> f a }

I define a general `Endo` type in the category package, here:

http://hackage.haskell.org/package/category-0.2.5.0/docs/Data-Morphism-Endo....

Thus one can use `Endo (Kleisli m)`. _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.

-- Debasish Ghosh http://manning.com/ghosh2 http://manning.com/ghosh Twttr: @debasishg Blog: http://debasishg.blogspot.com Code: http://github.com/debasishg