Mine hard negatives: optionally output similarity scores

[tsbalzhanov]

Hello

This PR adds an option to include similarity scores into result of mine hard negatives function.
This options might be helpful to fine-tune parameters of the mining function without a need to recalculate scores again or to extract logic of selecting negatives outside of the mining function.

Tsyren Balzhanov

[tomaarsen]

Hello!

I think it's indeed a good idea to also allow exporting scores, but so far I've introduced that via the n-tuple-scores: https://github.com/UKPLab/sentence-transformers/blob/1def8d3d6289e72bfa6a6a48592b1342053e6ff2/sentence_transformers/util/hard_negatives.py#L209

If we instead add a parameter akin to include_scores, then we'll have to deprecate the n-tuple-scores presumably. That's not really an issue, though. I'll do some more thinking on it.

• Tom Aarsen

[tsbalzhanov]

@tomaarsen

Hi, did you decide on what to do with output_format=n-tuple-scores?
I've just updated the PR: rebased on current master branch and made output_format=n-tuple with include_scores=True equivalent with output_format=n-tuple-scores

[tomaarsen]

Apologies for the delay. I think it would be preferable indeed to move towards output_scores and deprecate n-tuple-scores. If n-tuple-scores is passed, we can simply give a warning and set output_format="n-tuple" and include_scores=True indeed.

I want share that I'll be taking 3 weeks off starting Monday, so I won't be able to move this PR forward in the meantime. Apologies for this.

• Tom Aarsen

[tsbalzhanov]

If n-tuple-scores is passed, we can simply give a warning and set output_format="n-tuple" and include_scores=True indeed.

Okay, I've implemented this