Process attributes after Qed/Defined

[gmalecha-at-skylabs]

This PR extends the handling of attributes so that handlers are executed when the term is completed, e.g. at the Qed or Defined.

It uses this feature to implement a plugin that provides an attribute #[hint(db=...,cost=...,visibility=...)]. This should be either incorporated into core Rocq or introduced as a separate plugin.

For now, I'm just looking for feedback, the commits should be independently reviewable. The last commit contains the hint attribute implementation and could probably use more testing.

• Added / updated test-suite.

• Added changelog.

[gmalecha-at-skylabs]

@SkySkimmer What should the next steps here be?

1. I think it would be really useful to get the core part of the change in so that attributes on Lemma and whatnot work well. The only concern is that you could run into an error on Qed after you do a big proof.
2. What do you think about the code that actually implements the attribute? Should it be placed in a plugin that is distributed separately?

I'm happy to put more cycles into the development.

[SkySkimmer]

I think it would be really useful to get the core part of the change in so that attributes on Lemma and whatnot work well. The only concern is that you could run into an error on Qed after you do a big proof.

That seems fine, there doesn't seem to be a way to get the error earlier anyway.

What do you think about the code that actually implements the attribute? Should it be placed in a plugin that is distributed separately?

I don't see the point of having it be a plugin, it seems like it should be in the statically linked part. But do it as a separate PR since it has much more bikeshed potential.

[gmalecha-at-skylabs]

I have removed the plugin code from the PR.

[SkySkimmer]

@coqbot run full ci

[SkySkimmer]

@coqbot run full ci

[gmalecha-at-skylabs]

@SkySkimmer Do you want me to add a changelog entry? Is there anything else that needs to happen to get this merged?

[SkySkimmer]

I don't think we have any attributes defined with this system currently so there should be no user visible change right? (which is why you need a custom plugin for testing)
if so then it should be ready to merge, I think I just forgot to check back after running CI

[SkySkimmer]

@coqbot merge now