Constraints on definition of `length` should be strengthened

[Tony Morris]

Already done mate.

https://hackage.haskell.org/package/hask-0/docs/Hask-Category.html#t:Either
https://hackage.haskell.org/package/hask-0/docs/Hask-Category.html#t:Functor

Note the multiple Functor instances for Either and Coproduct. e.g.

- Functor * (* -> *) Either
- Functor * * (Either a)
etc etc

On 09/04/17 10:29, Henrik Nilsson wrote:
> And of course, if, in a hypothetical future version of Haskell
> where we could make all possible functor instances for tuples,
> the question becomes: which one do we pick? The answer might well
> be "none" (in the prelude, at least).


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 488 bytes
Desc: OpenPGP digital signature
URL: <http://mail.haskell.org/pipermail/libraries/attachments/20170409/3cd25073/attachment.sig>