No way to determine constant object's type over VPI

[ktbarrett]

Is your feature request related to a problem? Please describe.
When getting a VPI handle to a constant you are given a handle with vpi_get(vpiType, handle) = vpiConstant. There isn't currently a way to determine what the value type of the constant is. The function vpi_get(vpiConstType, handle) should help a bit, but right now it returns 0 (not a valid vpiConstType) for all types that I was able to test via cocotb. Not only that, but the range of values it can return is pretty limited; there is no way to say it's a constant std_logic_array.

Describe the solution you'd like
It would be preferable if constants were returned over the VPI as if they were regular objects, e.g. std_logic_vectors would return vpiNetArray for vpi_get(vpiType, handle). Then the property vpiConstantVariable, from the SV VPI extensions, could be supported to query whether the object is constant or not.

Describe alternatives you've considered
Implementing VHPI.

[tgingold]

Do you have an example or a testcase ?