[breaking] remove index_value function

[odow]

These functions were not called anywhere. We should remove unused things. People can just use .value.

[blegat]

It can be quite useful for solver wrappers to get the vector of index values from the vector of indices using broadcast. No solver use that ?

[odow]

If solvers need it they can define it themselves. There's also getfield.(x, :value). When in doubt, I vote remove. We want to minimize the surface area of MOI if at all possible.

[blegat]

It would be more readable if solvers use all a same documented way for doing so getfield.(x, :value) seems a bit hacky.

We want to minimize the surface area of MOI if at all possible.

I agree but it does not seem that we would need to ever break this function.

OTOH, it's true that we may not want to have two ways to do the same thing so it all depends whether we would consider getfield.(x, :value) to be a recommended way or not.

[odow]

It can't be that useful, because it isn't used anywhere in the whole of MOI. (Including in the tests...)

[odow]

I have the majority of solvers dev'd to my machine

[odow]

Bump.

[odow]

There is only one instance of someone using this:
https://github.com/search?q=%22index_value%22+language%3Ajulia&type=code

and that's @Azzaare:
https://github.com/JuliaConstraints/CBLS.jl/blob/8a8764fbbc78ddbc121127acab4e42be602d31e7/src/variables.jl#L46

[Azzaare]

I am on my phone atm so it will difficult to make the changes, but I don't mind updating the code to not use this function.

If one of you has a suggestion, I will update once I'm back home.

EDIT: I can change it to the get_field method above, but it does feel a bit like a hack haha. As long as it works, I don't mind.

[odow]

You never use broadcast. You only use index_value(x). So it's just x.value instead. or you can define index_value locally.

I think it's safe to standardize the API on .value, so we shouldn't have two ways of doing this.

[odow]

I found where it used to be used:

MathOptInterface.jl/src/Utilities/copy.jl

Line 95 in f559840

MOI.index_value,

thanks to the JuliaHub search engine:
https://juliahub.com/ui/Search?q=index_value&type=code&w=true

[Azzaare]

Since it is a breaking change, I suppose you will tag a new minor version.

In that case, you can merge this PR independently of CBLS.jl and I will make the change at the same I change the compat entry in the Project.toml

If for some reason the version will still be 0.9.x, let me know, and I will update before MOI.

[odow]

I suppose you will tag a new minor version.

Yes. We're well into breaking change territory. The next release will be 0.10 and require lots of changes.