Implementation puzzle

[bmxam]

I first introduced the DistributedSingleFieldFEFunction struct:
https://github.com/ghislainb/BcubeParallel/blob/222327b7e46840d7b229beabf12049b401d34402/src/interpolation/fefunction.jl#L5

to be able to specialize the function set_dof_values! to append a update_ghosts after setting the values:
https://github.com/ghislainb/BcubeParallel/blob/222327b7e46840d7b229beabf12049b401d34402/src/interpolation/fefunction.jl#L39

If you don't introduce a custom struct and only rely on the arguments of set_dof_values to dispatch:

function set_dof_values!(f::SingleFieldFEFunction{S,FE}, values; update_ghosts) where {S, FE <: TrialOrTest{S, <: AbstractDistributedSingleFESpace}
   update_ghosts(values)
  set_dof_values!(f, values) # wrong : infinite recursion !
end

this is a dead-end since you cannot call set_dof_values! on a sub-structure (but we could write feFunction.dofValues = (...), i.e copying the content of Bcube.set_dof_values! in BcubeParallel.set_dof_values).

The problem is that I now want to introduce the different FEFunction constructors (FEFunction(U, dofValues), FEFunction(fU, mesh, f) etc). It would be nice to do

function FEFunction(U <: AbstractDistributedSingleFESpace, args...; update_ghosts = true)
   feFunction = FEFunction(U, args...) # wrong : infinite recursion !
  # (...)
  return DistributedSingleFieldFEFunction(feFunction)
end

but again it's not valid because of infinite recursion.

In summary, we may need to better define what we want from a FEFunction in parallel (set_dof_values with update_ghosts or not?) before choosing an implementation.

[bmxam]

Possible solution : keep actual implementation but add _FEFunction in Bcube to call a lower level constructor from BcubeParallel

[bmxam]

Answer from ghislainb : https://github.com/ghislainb/BcubeParallel/issues/30#issuecomment-2941513922

Possible solution : keep actual implementation but add _FEFunction in Bcube to call a lower level constructor from BcubeParallel

I also use this kind of trick for tree structures (lazyop, ...)