Register custom metadata to completion provider

[Jarrio]

I'm not sure how much of an issue this would be to implement, but I think it would be a nice quality of life improvement to be able to register custom defined metadata to the provider.

@ or @: would be allowed, an API for this could be haxe.macro.Completion.registerMeta('property', 'description') something "simple"

[Simn]

IMO this should be handled in some declarative way. We already have src-json/meta.json, so a user-defined extension of that in the same format which is picked up by the compiler seems sensible.

[kLabz]

So each lib would provide their own meta.json which compiler would "merge" with its own meta.json?

[Simn]

Yes, and we can do the same with defines (although I forget where these show outside of --help-defines). I think the only question is how to tell the compiler where to look for these things. I thought we could just check the class paths, but I don't really want to mix JSON files with HX files...

[kLabz]

Maybe something similar to extraParams resolution (though it would only work for libs and not user code...), but that would probably require to translate it to some init macro call registering the file (which could be used directly for user code?)

[Jarrio]

a user definable meta.json would be a nice solution! something like a .hxml param -metafile path/to/metas.json

[Aurel300]

Small comment on this: keep in mind that the JSON files for metadata and defines are used during the compile time of the Haxe compiler. We can of course try to bring a similar mechanism to the Haxe compiler runtime.

[Simn]

Yes this would require moving some things around, but that should be doable even in OCaml.