Specialize `mapreduce` for `VectorValue` etc?

[ranocha]

Thanks for the nice package. I was playing around with it a bit and wanted to try out a toy problem (in different spatial dimensions) with analytical solution

u(x) = prod(sinpi, x)

However, this does not work right now since x::VectorValue and VectorValue <: Number. Thus, prod hits mapreduce with special case https://github.com/JuliaLang/julia/blob/7dc132cf5a44717dbb619812dc05fd127c9d805a/base/reduce.jl#L438 which tries to handle x as a single number instead of an iterable.

Do you think it would make sense to specialize mapreduce for cases like this? Right now, I need to use a workaround such as

u(x) = prod(i -> sinpi(x[i]), eachindex(x))

[kishore-nori]

Not a solution, but an other alternative fix for this is

u(x) = prod(sinpi, x.data)

like you mentioned it might be best and general to specialize TensorValue family for mapreduce.