[FeatureRequest]: Have isnan return true for an array value instead of error

[DonStauffer]

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

I'd like to be able to tell whether something is an array or not.

Describe the solution you propose.

I propose having the isnan function return true for an array value

Describe alternatives you've considered

Everything I've tried throws an error either when the value is or is not an array. For example, passing the first element of an array to exists produces an error (logically) if the value is actually not an array.

Provide any additional context or information.

What I'm doing right now is trying to pass a parameter to a macro, where the macro behaves differently if you pass a 1D or 2D array.