Hi!
I’m trying to provide/extend an existing Erlang behaviour in a library to use it with Elixir.
Said behaviour is called :riak_core_vnode, it has some setup quirks to make it to work with Elixir, so I wanted to make a sort of a wrapper behaviour, my idea is to create a module that implements said behaviour and defines a new behaviour (let’s call it :elixir_vnode for clarity’s sake). Then, a user of this behaviour would only have to implement it and the only thing my module should be doing is call the user’s defined function.
A more concrete example would be something like this:

defmodule MyWrapper do
 @behaviour :quirky_erlang_behaviour
 @callback not_weird_function(params :: any) :: :ok
 def weird_function(params) do
   UserDefinedModule.not_weird_function
 end
end

First thing that comes to mind is to use a config option to determine which module is UserDefinedModule, something like:

config :my_lib, user_provided: UserDefinedModule

And then, weird_function would be something like:

def weird_function(params) do
  user_module = Application.get_env(:my_lib, :user_provided)
  user_module.not_weird_function
end 

Is there a cleaner, or more simple, way to do this?