I don’t think the following is possible, but going to ask for possible solutions.

I have the implementation of a Protocol with 5+ functions with 10+ modules implementing them.
A lot of these implementations have a default implemenation, like they don’t need to do a lot.
The problem I have is that I need to add a new function to the protocol, but the only way to do that is to update all the functions in 1 go. I’d rather not to that, as I first want to validate if the thing I’m trying is actual a valid thing to do.

So, what I’m wondering is, can I do something like defimpl for only 1 function of a protocol.
I guess that’s not possible, but I was wondering how you would solve something like this.

FYI, this is the current protocol:

defprotocol DomainModelling.Block do
  def advance?(data)

  def evaluation_pattern(data)

  def evaluate(block, params, session_state)

  def state(block)

  def dependencies(block)

  def classify(block)
end

The reason I chose for a protocol is because I want to be able to add extra implementations, without the code using it being impacted. For example I have test modules that implement the protocol.

I guess one possible solution, is to just skip the protocol completely and use duck typing.

Any other ideas? It’s possible that I just need to rethink my design.