Diamond cond with OrConjunction

[dengdifan]

This PR works on solving a potential error that might occur for a hierarchy configuration space with OrConjunction:
Suppose that an HP top has two choices A and B and an HP bottom that is conditioned on A or B: (bottom | top == A || top == B). Then if top switches from A to B, bottom should remain to activate (A more concrete example could be found under test/test_util.py::UtilTest::test_check_neighbouring_config_diamond_or_conjunction).

An additional check is attached under change_hp_value. However, this might make the check slower: we need to check all the children conditions and not skip them as before

[codecov]

Codecov Report

Merging #219 (3f62ff2) into master (4d69931) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #219   +/-   ##
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  Coverage   67.15%   67.15%           
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  Files          17       17           
  Lines        1629     1629           
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  Hits         1094     1094           
  Misses        535      535           

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[eddiebergman]

Just need to ask about the odd == thing. Otherwise a rough understanding of the code and the test seem to be correct.

[eddiebergman]

This seems odd? current_value == current_value, is this not always true?

[dengdifan]

Not really, if current_value is deactivated, then this equation does not hold (Similar code can be found under line 335 and 344)

[mfeurer]

No, two NaNs compare as unequal, see https://en.wikipedia.org/wiki/NaN#Comparison_with_NaN. This is the fastest way to check for NaN values because it does not require any additional function calls.