Bring YouRM .forward signature in-line with Retrieve child class .forward methods (add K kwarg)

[mgbvox]

The following code (snippet) follow the setup idiom currently used by dspy:

class WebRag(dspy.Module):
    NL_SEP = "\n----------\n"

    def __init__(self):
        super().__init__()
        # uses you_rm as declared below:
        self.you_rm = dspy.Retrieve(k=5)
        self.chain_of_thought = dspy.ChainOfThought(...irrelevant_signature...)

    def forward(self, question: str):
        web_context = self.NL_SEP.join(self.you_rm(question).passages)
        out = self.chain_of_thought(web_context=web_context, question=question)
        return out.answer
...

rm = YouRM(ydc_api_key=settings.YDC_API_KEY.get_secret_value())
lm = dspy.OpenAI(model=settings.LLM_MODEL, api_key=settings.OPENAI_API_KEY.get_secret_value())
dspy.settings.configure(lm=lm, rm=rm)

However, invoking this with a question string raises the following error:

web_rag = WebRag()

out = web_rag("What is the meaning of life (according to Douglas Adams)?")

# ERROR:
#  File "/Users/mgb/miniforge3/envs/nlu/lib/python3.9/site-packages/dspy/retrieve/retrieve.py", line 29, in __call__
#    return self.forward(*args, **kwargs)
# TypeError: forward() got an unexpected keyword argument 'k'

This is due to retrieveEnsemble in search.py invoking YouRM's .forward with an additional k kwarg.

Inspecting other modules in dspy/retrieve (e.g. chromadb.py) shows that k is desired as a kwarg to retrieve forward invocations; I therefore added this to YouRM's .forward and also to the parent .forward implementation in retrieve.py.

[CShorten]

Lgtm! Was thinking about doing this as well, super important!

[okhat]

That was fast @mgbvox ! And thanks for the check @CShorten — I saw your comment and knew I should merge asap :D