Mixin support

[valaphee]

Is your feature request related to a problem?

Sometimes plugins are not enough to modify certain server behavior, or the solution would be way more complicated.

Our use cases would be:

• special attributes which nullify all other attributes
• server side translation in items and configuration phase packets, which will likely not get upstreamed

Describe the solution you'd like.

Mixins would allow to change such behavior in a more composable way then overwriting classes. Basically adding modding capabilities to paper.

Describe alternatives you've considered.

There are plugins like Horizon and Ignite, which add mixin capabilities to Paper. But having this feature directly in Paper, would make setup easier, and its more guaranteed to be maintained, compared to small, less adopted 3rd party projects.

Other

I of course know that it might not be in scope of Paper

[lynxplay]

PaperMC/Paperclip#62 (comment)