Local Grid Refinement: function unsuitable now can be used with only 2 arguments

[bozhar]

it uses such arguments as barycentric coordiantes and area/volume. It work in both 2D and 3D.
This unifies the signature for both 2D and 3D.
New doc page has been added.

[pjaap]

Thank you very much for this PR!

Can you please change the commented lines below and:

• set the Version in Project.toml to 1.8.0

[pjaap]

@j-fu what do you think?

[j-fu]

This is the idea with the callable struct:

abstract type AbstractUnsuitableCallback end

struct MyCallback <:AbstractUnsuitableCallback
end

function (::MyCallback)(center, volume)
         ...
end      

Then we can set unsuitable!(MyCallback()) and check if isa(opt[:unsuitable], AbstractUnsuitableCallback)

[pjaap]

I see the problem with the .nargs ... it is hacky. I was my idea, so I take the blame 😄

I want to keep it very clean on the user side, so the CallableStruct is not a good idea. But what about something like

opts_unsuitable = opts[:unsiutable]
function unsuitable(pa, pb, pc, pd)
    if hasmethod(opts_unsuitable, Tuple{typeof(pa), typeof(pb), typeof(pc), typeof(pd)})
        return opts_unsuitable(pa, pb, pc, pd)
    else # assume two-argument function
       center = ...
       vol = ....
       return opts_unsuitable(center, vol)
    end
end

for TetGen ... and similar for Triangulate?

[pjaap]

applicable may be better candidate: https://docs.julialang.org/en/v1/base/base/#Core.applicable

[bozhar]

Changes (from 14.10.2026):

- Ideas from the discussion were implemented
- defined the function set_unsuitable!, which invokes a callback function:
-> applicable to both Triangulate and TetGen
-> implemented within utils.jl.
-> utilized across triangle.jl and tetgen.jl
-> automatically infers the input type
-> enables the consistent application of the unsuitable function across multiple contexts, thereby preventing code clutter and preserving modularity

[pjaap]

I like this now. What do you think @j-fu