Imported AssnsCrosser algorithm from icarusalg [1/3]

[PetrilloAtWork]

AssnsCrosser is an utility in icarusalg helping to hop across chains of associations.
While it's not a silver bullet and it works on some assumptions, it's usually easier than trying to sort out the several association levels. Documentation is inline and currently in ICARUS Doxygen rendering (in icarus namespace).

Given the extensive need of association hopping, I am proposing here to move it into sbnalg, where it can be used by almost the whole art-aware SBN code base.
The header path is changed accordingly, like the namespace that is moved from icarus::ns::util to sbn::ns::util¹. Because of this, this is a breaking change, which is easy to fix.

Dependent pull requests

Connected pull requests are in:

• Imported AssnsCrosser algorithm from icarusalg [2/3] icarusalg#94 (where the equivalent code is removed)
• Imported AssnsCrosser algorithm from icarusalg [3/3] icaruscode#825 (fixes for the breaking change)
  I do not know of any other place where this utility is used (and not much code is aware of icarusalg beside icaruscode).

Reviewers

• @SFBayLaser as the maintainer of ICARUS software repositories;
• @absolution1 as the maintainer of SBND software repositories.

... and that's it because I don't know who else.
This is a technical PR, that only involves details like old and new names and places.
Of course, people are also welcome to contribute comments on the merit of the algorithm, but I expect that this would not have specific consequences for this PR.

The unit test was moved and still passes.
Note that in my (unit) test one of the tests fails due to broken FHiCL configurations (related to ICARUS overlay) which are not related to this PR. This PR did not touch any FHiCL file and is not supposed to break any of those.

[1] ns stands for "namespace" and was meant to remove the ambiguity of icarus::util namespace with util when working in icarus namespace. Whether this trick actually helps is questionable.

[kjplows]

Hi @SFBayLaser , just bumping this - could you please take a look at this PR? Thanks!

[SFBayLaser]

I am happy to see this addition and happy to approve.

[hgreenlee]

trigger build LArSoft/lar*@LARSOFT_SUITE_v10_20_06 SBNSoftware/sbndaq-artdaq-core@v1_10_06 SBNSoftware/sbn*@SBN_SUITE_v10_20_06 SBNSoftware/icarusalg#94 SBNSoftware/icaruscode#825 hgreenlee/sbndcode@test614

[FNALbuild]

✔️ CI build for LArSoft Succeeded on slf7 for c14:prof -- details available through the CI dashboard

[FNALbuild]

❌ CI build for ICARUS Failed at phase build ICARUS on slf7 for c14:prof -- details available through the CI dashboard

🚨 For more details about the failed phase, check the build ICARUS phase logs

parent CI build details are available through the CI dashboard

[FNALbuild]

❌ CI build for SBND Failed at phase build SBND on slf7 for c14:prof -- details available through the CI dashboard

🚨 For more details about the failed phase, check the build SBND phase logs

parent CI build details are available through the CI dashboard

[FNALbuild]

✔️ CI build for LArSoft Succeeded on slf7 for e26:prof -- details available through the CI dashboard

[FNALbuild]

⚠️ CI build for SBND Succeeded with warning at phase build on slf7 for e26:prof - ignored warnings for build -- details available through the CI dashboard

parent CI build details are available through the CI dashboard

[hgreenlee]

Merged to branches main + develop.

[FNALbuild]

❌ CI build for ICARUS Failed at phase ci_tests ICARUS on slf7 for e26:prof - ignored failure for unit_test - ignored warnings for build -- details available through the CI dashboard

🚨 For more details about the failed phase, check the ci_tests ICARUS phase logs

parent CI build details are available through the CI dashboard