RE: Arrow operator and empty sequences

> 
> I agree with Christian.  I think a key difference with path expressions is that
> the RHS operand is not called once per item in the result of evaluating the
> LHS operand (which indeed, is zero times for the empty sequence).
> 
> With the arrow operator, the RHS is called exactly once, whatever the result
> of evaluating the LHS.
> 

Yes, I think that makes sense, albeit a trifle unintuitive. So the LHS cannot work as a filter (but we have "/" and "!" for that, which *does* work that way, i.e., if LHS is empty, RHS needs no eval)