Specifying metadata in MTK-Model DSL

[ctessum]

Is your feature request related to a problem? Please describe.

We currently use system metadata for a number of different purposes, for example here. We would also like to use the DSL to define models, but currently (as far as I can tell) the DSL doesn't allow specifying system metadata.

Describe the solution you’d like

If it is already possible to specify metadata, I guess just clearer documentation of that feature would be useful. Otherwise, maybe a design something like this:

using ModelingToolkit
using ModelingToolkit: t
using Test

struct TestMeta1 end
struct TestMeta2 end

@mtkmodel ModelA begin
    @description "A component with parameters `k` and `k_array` and some metadata."
    @parameters begin
        k
        k_array[1:2]
    end
    @metadata Dict(
        TestMeta1 => "test1",
        TestMeta2 => "test2"
    )
end

sys = ModelA()
@test getmetadata(sys, TestMeta1) == "test1"
@test getmetadata(sys, TestMeta2) == "test2"