Shorthand for adding multiple fields to the dofhandler

[KnutAM]

Original suggestion here #676, with #872 we could have

fields = (u = Lagrange{RefTriangle, 2}()^2, p = Lagrange{RefTriangle, 1}())
qr = QuadratureRule{RefTriangle}(2)
ipg = geometric_interpolation(grid)

dh = DofHandler(grid)
add!(dh, fields)
close!(dh)

cmv = MultiFieldCellValues(qr, fields, ipg)

(And for convenience we could also support dh = DofHandler(grid, fields) which closes automatically which is nice for quick examples :))

[KristofferC]

Could it be a vararg?

[KnutAM]

Could it be a vararg?

You mean as keywords? DofHandler(grid; u = ipu, p = ipp)?
(I had that for MultiFieldCellValues first, but removed it to allow the kwarg we have for the update choices. And I guess it could be similar here, that in case we later want to add some options to DofHandler it would be bad to remove that option?)

[termi-official]

The original suggestion was rather something like taylor_hood_ip = Lagrange{2,RefTriangle,2}()^2 × Lagrange{2,RefTriangle,1}() (#676 (comment)) such that we can do something like #676 (comment) . With #872 we can now put this hypothetical object into FEValues. Other possibilities are

:u \in Lagrange{...}
(:u, :p) \in Lagrange{...} \times Lagrange{...}
(:u \in Lagrange{...}) \times (:p \in Lagrange{...})

[KristofferC]

You mean as keywords?

Ah, sorry, forgot you need the name as well.