?dup

Hi,

Here's a ?dup implementation, based on a subroutine rather than inlined 
code.

Samuel, if you feel an inlined version is more appropriate, you could 
implement a macro or meta version instead.

     code ?dup
         indf ,w     movf
         z           btfsc
                     return
                     pushw
                     return
     end-code

-- 
Cheers
David