[Push] Code.Nth

[PerPlex Ed]

Thanks. As I said, I'm trying to be conforming to the original 
implementation, so I changed my code to push back an empty sequence 
instruction and return.


Lee said:
> In the Common Lisp 
implementation if the code into which you're indexing is an empty list 
then the pushed result is itself an empty list. That is, nth of () with 
any index is (), so you'd get another () on top of the code stack. Maybe that just made sense to me because of the equivalence of () and nil (= 
empty list = nothing) in Common Lisp. I could see that other answers 
(e.g. noop) might be just as good, and as long as you're consistent I 
wouldn't expect it to matter much (except for porting programs between 
implementations!).