Syntactic vs Semantic discovery.

[DavidDudson]

Syntactic

Search for an annotation with the appropriate name. Not fully qualified.

Pros: Extremely fast, no overhead. Cons: Will break if two annotations with the same name exist.

Semantic

Searches for an annotation with the correct fully qualified name.

Pros: Safe Cons: May have to build a semantic database of the source file

I believe that we should stick with syntactic discovery for now. If enough users wish for semantic discovery we should add it via a flag, so that those who don't need semantic discovery, do not have to take the performance hit.

[olafurpg]

Semantic discovery has one more advantage: generators can access the fully qualified names in the code. I think for now we can start with syntactic discovery just to get off the ground, I'm happy to help setup semantic discovery later down the road. The changes should be

• enable semanticdb-scalac in the app-gen project
• pass classDirectory to scalagen
• pass SemanticdbIndex to generators (does not exist yet, we should move the one in scalafix to scalameta)

[DavidDudson]

I propose we push for at a bare minimum FQN discovery for 0.1, with the potential for semantic-db etc. being added to generator contexts for 0.2