Re: [Haskell-cafe] Haskell function composition commutivity?

Your answers seem to originate outside of normal Haskell tutorials. Where can I start with this higher superset theory? On Tue, Apr 13, 2021 at 1:19 PM Viktor Dukhovni wrote:

...

On Apr 13, 2021, at 2:02 PM, Tom Smeding wrote:

Although, because of the fact that you omitted 'Functor f =>' and instead chose to write the constraint in prose beforehand, I get the feeling that you may be speaking mathematically, not about Haskell as compiled by GHC.

Yes, mathematically, with Haskell-like syntax. Also the functors in question were intended to stand for specific functors, rather than be universally quantified.

So perhaps better:

Yoneda (with A some type and F some functor):

foo :: forall b. (A -> b) -> F b

<=> foo bar = fmap bar (foo (id @A)

-- Viktor.

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