Thanks, missed that. Is there perhaps a better UnaryExecutor that would process NULLs the way we need it? Or perhaps a template argument that we need to set?

I don't think I've seen any. We could try to generalise what we have here into a variant of Un|Bi|*|naryExecutor that would have an additional path for when it sees a NULL. That would perhaps be easy for Unary but then I'm afraid things will get exponentially more complicated as there are more inputs.

I might have missed an already existing solution though cc @hannes ?

Perhaps to rephrase: is there a UnaryExecutor and BinaryExecutor that treats NULL like any other value, and computes the result for both NULL and non-NULL inputs by calling some lambda? (Is NULL even representable in a Value object?)