Putting non-protocol functions in a protocol?

[Qqwy]

@LostKobrakai

In the end I question if you actually need ˋemptyˋ on the protocol, because how useful is ˋArray.Protocol.empty(…)ˋ if there‘s nothing to dispatch on. For ˋEnumˋ one would also do ˋMapSet.new(list) |> Enum.map(…)ˋ as well.

There are two differences between Enum and Array.

1. (virtually) all Enum functions change the enumerable into a list anyway, making something like starting with e.g. MapSet.new less useful/common.
2. The interface exposed by the different array-presentations is identical. It therefore seemed like a good idea to move the choice of implementation from the code into the configuration. In many cases it makes sense to pick a particular implementation project-wide rather than module- or function-specific. Not having to change the code to benchmark/profile the impact of the different implementations in a particular application seems to be an added benefit here.

Currently there is an Arrays module with the user-facing code, the Arrays.Protocol module that defines the protocol and the Arrays.Behaviour module that defines the related behaviour (consisting only of empty).