So I've been working on a #golang tool that will take in a JSON-LD RDF specification (like the #ActivityStreams one here :https://github.com/gobengo/activitystreams2-spec-scraped/blob/master/data/activitystreams-vocabulary/1528589057.json) and spit out generated Go code that automatically generates the static types for it.
The intent is, ActivityStreams extensions would be able to host this specification as their @context reference, people could use this tool to auto-generate the extension for their Go code, and then build their apps with it.
The intent is that the rest of the go-fed library would then be able to automatically pass-through these static types as needed (I am big on avoiding the reflection penalty, and keeping everything compile-time-safe). So folks building their #ActivityPub federated apps in Go on top of go-fed will be able to always pick and choose which extensions to support, and always skip to the "build the app" step instead of the "roll my own ActivityPub implementation" step.
@mariusor If a vocabulary adds a new property and the generated go code doesn't recognize it, it just treats it like any other unknown property and transparently preserves it (requirement of ActivityPub). The only reason to recompile and redeploy is to update the app code to do something with this new field, which would require a regenerate+recompile+redeploy anyway. Reflection doesn't buy anything unless the entire app server is basically written with the reflection package types.