Update _split_one_line and remove whitespace parameter

[xvlaurent]

This is an attempt to update _split_one_line function to avoid usage of 'whitespace' parameter and approximation made for '_atom_site' CIF block.

Performance have to be approved with a CI run.

[codspeed-hq]

CodSpeed Performance Report

Merging #686 will degrade performances by 19.46%

_{Comparing Discngine:split_line_enhancement (c465aa5) with main (8fd73bf)}

Summary

❌ 2 (👁 2) regressions
✅ 45 untouched benchmarks

Benchmarks breakdown

	Benchmark	main	Discngine:split_line_enhancement	Change
👁	benchmark_get_structure[cif-False]	62.4 ms	77.5 ms	-19.46%
👁	benchmark_get_structure[cif-True]	124.6 ms	139.3 ms	-10.5%

[padix-key]

Hi, thanks for preparing this PR. The benchmarks show that this variant is indeed slightly faster than than the regex-based one. However is still about 40% slower than the fast expect_whitespace=False hack. This makes parsing a structure without bonds about 20% slower (as shown above).

Still, I tend towards accepting this change, because it is much cleaner and technically gives the correct result, while currently it does not. If high performance is desired, I would recommend using BinaryCIF anyway. @biotite-dev has anyone a strong opinion about it?

I probably need a few more days to review the code, but for now could you reformat the code with ruff? Currently the CI check is failing.

[padix-key]

Fixes #673

[xvlaurent]

I tryed to reduce/optimize the code a bit more, but it seems there is no real gain...

[padix-key]

This is okay, a few other people (including me) already tried that unsuccessfully. After Rust code is introduced into the project (#688), this is probably the first function that is replaced by fast Rust routine.

The PDBx test is currently failing, as it does not expect a generator. Could you either revert to the non-generator variant or adapt the test?

[xvlaurent]

Finally, all tests are fine and branch is up to date!

[padix-key]

I only found this small typo. Otherwise the PR looks good to merge!

[padix-key]

Only a small typo

Suggested change

	striped_line = line.lstrip()
	stripped_line = line.lstrip()

[xvlaurent]

Typo fixed! Thanks.