Add instance Data a => Data (ZipList a) to base

Edward Kmett ekmett at
Mon Nov 4 19:15:24 UTC 2019

You can consider this email a judgment from the base maintainer on the CLC
that it is okay to add these missing Data instances.

That should be enough to not get the issue thrown out of the ghc issue

We already had the discussions in the CLC back a couple of years ago
approving adding missing common instances when uniquely defined. These seem
to have been missed in the previous passes.

Now we just need a patch.


On Mon, Nov 4, 2019 at 10:29 AM Mario Blažević <mblazevic at> wrote:

> On 2019-11-04 10:23 a.m., David Feuer wrote:
> > I don't think we really need to go through the proposal process to add a
> > Data instance when we already have a Generic instance or vice versa.
> What should I do instead? Open an issue? The bug tracker link on Hackage
> is broken, BTW. It works without the last path component.
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> Libraries mailing list
> Libraries at
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