Add magic method between TelemetryRegistry.get_events/1 and Module.get_attribute/3

[garthk]

I'd love to make TelemetryDecorator event names easier to discover (amplifiedai/telemetry_decorator#2). Assuming I can figure out a way to emit module-level AST chunks (arjan/decorator#42), the next trick will be making the dependency on TelemetryRegistry optional. Strikes me registering the attribute myself is rude, which might introduce a race. Bah!

If your macro defined a José-style magic method eg. __telemetry_registry_details__/0 in the module exposing the results of Module.get_attribute/3, though, I could do the same in an API-compatible way using my own attribute. We'd each have to check Module.defines?(__MODULE__, {: __telemetry_registry_details__, 0}) and defoverridable __telemetry_registry_details__: 0 if so, bu— this is getting silly; maybe I should just invoke your macro. Thoughts?

[hauleth]

You could use Erlang API, which mean that all you need is to create Module.register_attribute(__MODULE__, :telemetry_event, persist: true, accumulate: true) and then just create all entries needed. You do not need to use Elixir macros to define these on your own.