Oh. Error handling for negative index was never an issue for the simple fact that we work with SQL/database tables. I believe this was the trump card used against me (I was pro-0 IO since it would be natural when working with J). Table columns and rows always start with 1. :) Or as database programmers would always say 1st row or 1st column ...
-----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of bill lam Sent: Wednesday, July 28, 2010 7:56 AM To: [email protected] Subject: Re: [Jprogramming] index origin 0 Втр, 27 Июл 2010, Alex Rufon писал(а): > +-+-+-------------------------------------+ > |4|:|NB. indices-of-elements (IO=1) from y| > | | |(_1 + x) { y | > +-+-+-------------------------------------+ This equation is interesting. So when counting from the end. the last item is A[0], the second last item is A[-1] ie. index origin 0 whereas for J the last item is A[-1], second last is A[-2] ie, index origin 1 To be more correct for human domain so that always use index origin 1 when counting both from the beginning and from the end, it can be improved as if. 0=x do. assert. 0 elseif. 0<x do. (_1+x){y elseif. do. x{y end. How does APL interpret negative index for either index origin? -- regards, ==================================================== GPG key 1024D/4434BAB3 2008-08-24 gpg --keyserver subkeys.pgp.net --recv-keys 4434BAB3 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
