Use WeakKeyIdDicts.jl

[haberdashPI]

Hey there! I copy/pasted the internal WeakKeyIdDict implementation found in this repo to make use of it in other packages (rather than depending on an implementation internal to this package; and really, I don't need to depend on all of the stuff in here just to use a WeakKeyIdDict 😄 ).

You can find it here: https://github.com/beacon-biosignals/WeakKeyIdDicts.jl

I'm wondering if it would make sense to have AbstractAlgebra depend on it rather than use the internal implementation.

[fingolfin]

Hey there, I am glad that code is useful to you, and I am happy if you want to put it into a package.

However, I'd appreciate if this did a bit better job at documenting the license, copyrigh and origin of this code. And so should we, really!

Regarding the license file in your repository, I find it rather inappropriate that it starts with "Copyright (c) 2021 Beacon Biosignals" -- that's just wrong in every possibly way.

You go on to quote the AA license. Unfortunately (and you can't know that, of course) that license file is also in a bad state, and for this particular bit of code, the copyright line "Copyright (c) 2014-2016: William Hart, Tommy Hofmann, Claus Fieker, Fredrik Johansson" is also completely inappropriate: none of these people worked on that code in question, and certainly not in that time range ;-)

Let's unravel this a bit then. The code evolved through these PRs on various repositories:

1. WIP/RFC: Converted WeakKeyDict to hash & compare with object-id JuliaLang/julia#28161
2. WeakKeyIdDict implementation (keeping WeakKeyDict) JuliaLang/julia#28182
3. Implemented WeakKeyIdDict JuliaCollections/DataStructures.jl#402
4. Added data-structure WeakKeyIdDict oscar-system/Oscar.jl#1872
5. Add WeakKeyIdDict #1419 (which was finally merged)

The first four of these were all by @mauro3 who definitely should get credit. I then took the code in the penultimate PR and turned it into the final PR. I then spent some time bug hunting and rewrote multiple parts of it to match latest Julia WeakKeyDict implementation (this was necessary to fix a bunch of bugs!), and also added several more tests to get the coverage up

The Julia codebase is under MIT licenses, and I think @mauro3 also had that license on his code, and I also don't mind; so it would be fine to have just the MIT license in your repository. But I think it would be reasonable to briefly explain the genesis of the code at the bottom of your README.md and/or in the license file. As to copyright, perhaps this for the license file.

Copyright (c) 2016-2023 The Julia Team
Copyright (c) 2018-2023 Mauro Werder
Copyright (c) 2023 Max Horn
Copyright (c) 2024 Beacon Biosignals

[fingolfin]

As to changing AA to depend on your package: I don't see a benefit for us in doing so at this point.

[haberdashPI]

Thanks for spelling that out @fingolfin, I'll update the license.

[haberdashPI]

FYI: beacon-biosignals/WeakKeyIdDicts.jl#14