Get rid of declareSchemaRef's Proxy argument in favour of TypeApplications

[23Skidoo]

Would be nice if I could write

declareSchemaRef @Username

instead of

declareSchemaRef (Proxy :: Proxy Username)

Any objections? I can probably look into making a patch.

[23Skidoo]

Main downside of this is that it will mean losing compatibility with GHC < 8.

[jonathanjouty]

Would this work well with servant-swagger?
In particular, if you only want a sub-part of the API to be part of the Swagger definition.

Would something like this work?

type API = PublicAPI :<|> InternalAPI

mySwagger :: Swagger
mySwagger = toSwagger @InternalAPI

[phadej]

@jonathanjouty This change is not related to servant-swagger at all. swagger2 to servant-swagger is like aeson is to servant (exaggerating, but close).

@23Skidoo I'd like to be consistent. What about Data.Swagger.TypeApplications with variants without Proxy argument (and AllowAmbiguousTypes enabled only there). Removing Proxy arguments would break everyone; that's not something I'd like to do. :(

[phadej]

Yet, I'd like to remove polymorphic proxy :: to make things DerivingViable.

[23Skidoo]

What about Data.Swagger.TypeApplications with variants without Proxy argument (and AllowAmbiguousTypes enabled only there). Removing Proxy arguments would break everyone; that's not something I'd like to do. :(

Fine with me.