refactor: Deduplicate get_expectation

[rht]

I have tested on both maxcut and hydrogen-lattice. They both work fine.

[rht]

@rtvuser1 what are the concrete requirements for this PR to be merged? This is just a small step in my further attempt to make the benchmark code simpler and more readable.

[rtvuser1]

There is a larger question that comes up with this PR. There are no issues with the functionality you proposed.
However, there are many functions like this that should be consolidated. Before merging this PR, we want to consider it in the context of all the other related issues. There will be a contributor investigating this starting sometime early Feb, and we can merge your request as part of this. We are reluctant to add a new shared file with a name like "lib" (and the function within), without first considering the larger plan. Let us know if you would like to be involved in the discussion and planning on this.

[rht]

We are reluctant to add a new shared file with a name like "lib" (and the function within), without first considering the larger plan. Let us know if you would like to be involved in the discussion and planning on this.

Yes, sounds good to me. But I'd appreciate if the discussion would have been more open regardless, given that this is an open-source project/repo. There are always eyeballs and potential contributors to the refactor effort.

[rtvuser1]

I would definitely like to take this up again shortly. I agree the discussion should be open. The improvement suggested by your PR is a good one.

[rht]

Thank you! There are several benchmarking attempt out there (among the most recent ones being https://arxiv.org/abs/2401.09076). My take is that for QC-App-Oriented-Benchmarks to be the go-to place for people to look at, code clarity is essential.