Write an extension to integrate ap4k features in Quarkus

[emmanuelbernard]

https://github.com/ap4k/ap4k

A prototype to get it working on top of Protean would be a awesome extension.

The one big difference if at all possible is to not use APT but instead the Protean infrastructure which to sum up is after compilation, reading annotations from Jandex to then generate the resources that AP4K
generates.

I might be wrong in my understanding of AP4K but I think aside from the annotations which are metadata, there is no code generation where the generated code is itself referenced by the user code. So we don't need an APT like tool.

[geoand]

@iocanel Let me know if you want an extra set of hands for this one

[iocanel]

So, ap4k is not coupled to apt, the actual logic could work without apt, if we had a way to get the annotation information. Jandex seems to solve that, so I guess it shouldn't be that hard.

[iocanel]

I made some progress on the ap4k side of things(see 1). In particular, I moved all the logic outside of the apt processors. Also, I code generated adapters, that would make it slightly easier to adapt jandex classes (AnnotationInstance) into the internal ap4k representation.

So, what's left is to hook everything to protean. Any ideas on where I should add this integration/extension?

[emmanuelbernard]

Fantastic @iocanel ! I was just talking about ap4k in Protean with quite a few folks this week. I would looove to have this for 🚀
If you ask where to put the extension code, they all are here at the moment
https://github.com/jbossas/protean-shamrock/tree/master/extensions

[geoand]

@emmanuelbernard please assign me to this as well :).
@iocanel and I have been looking at this and although we are close, we still need to sort out some details