Daan Huybrechs

> Probably make it plural a la ChainRulesCore.jl and StaticArrays.jl (either DomainSetsCore.jl or DomainsCore.jl) DomainSetsCore.jl seems to be the most common suggestion (DomainsCore reads a bit like DomainScore)

I'm warming up to the idea of an interface. Looks like it might work and solve several issues. (And perhaps create new ones, but we'll see.)

This seems like an example of a package providing an interface not unlike what is proposed above: https://github.com/JuliaMath/DensityInterface.jl (edit: to be clear, the interface is for a different field, not...

Update: see [here](https://github.com/JuliaApproximation/DomainSetsCore.jl) for a possible DomainSetsCore.jl package.

Update: for experimentation I've made a first working version of [DomainSetsCore.jl](https://github.com/JuliaApproximation/DomainSetsCore.jl) along with IntervalSets.jl and DomainSets.jl. Aiming for interfaces rather than inheritance, intervals in IntervalSets on [this branch](https://github.com/daanhb/IntervalSets.jl/tree/domainsetscore) no longer...

I've made a few PR's to make it easy to see the changes: IntervalSets: https://github.com/JuliaMath/IntervalSets.jl/pull/155 DomainSets: https://github.com/JuliaApproximation/DomainSets.jl/pull/140 In these PR's, Domain{T} moves to DomainSetsCore, and intervals continue to inherit from...

> I didn't realize that this is the key challenge, but your example with `union` makes it very clear. I'm going to try to think about it some more. One...

> One story that I am interested in: let's say that I am the author of GeometryBasics, and I want `union(DomainSets.Rectangle([0,0], [1,2]), GeometryBasics.Rect(0,0,1,2)` to work better than it currently does...

Alternatively, the behaviour of `uniondomain` can be changed more directly. By default `uniondomain(d1,d2)` invokes `uniondomain1(d1,d2)`, which in turn calls `uniondomain2(d1,d2)`, which returns a `UnionDomain`. You can dispatch on the type...

The build fails because DomainSetsCore hasn't been registered yet. All tests pass locally for me.