'a b c'=:a:;a:;a: a ┌┐ ││ └┘ b ┌┐ ││ └┘ c
Note that c is empty, but a and b are "empty boxes". Linda -----Original Message----- From: programming-boun...@jsoftware.com [mailto:programming-boun...@jsoftware.com] On Behalf Of Raul Miller Sent: Friday, June 01, 2012 10:41 AM To: Programming forum Subject: Re: [Jprogramming] take ; has two kinds of behaviors. One kind of behavior is evident when dealing with sentences where the supplied nouns are unboxed: 1;2;3 +-+-+-+ |1|2|3| +-+-+-+ The other kind of behavior is evident when dealing with sentences where the supplied nouns are boxed: a:;a:;a: +--+--++ |++|++|| |||||||| |++|++|| +--+--++ From a high level point of view, the rightmost element gets special treatment when it is already boxed. From a low level point of view, the rightmost element gets special treatment when it is unboxed. This distinction exists because of the structure of J's expression grammar. http://www.jsoftware.com/help/dictionary/dicte.htm In some ways, this issue is analogous to the distinction between a dotted pair and a normal list element in LISP (except, of course, J does not have cons cells -- dyadic verb definitions roughly occupy that role in the language). FYI, -- Raul On Fri, Jun 1, 2012 at 8:46 AM, Steven Taylor <tayl...@gmail.com> wrote: > "Oh, that's the asymmetry of ; again!" > > I should have realised! Oops. I was pleased to find that a: worked > when I tried it. Didn't see that in any of the documentation that I looked > at. > > thanks, > -Steven > > On 1 June 2012 12:55, Brian Schott <schott.br...@gmail.com> wrote: > >> Bob (and Henry, of course), >> >> That is a terrific explanation. Thanx to both of you. >> >> On Fri, Jun 1, 2012 at 1:49 AM, bob therriault >> <bobtherria...@mac.com> >> wrote: >> > Hi Steven, >> > >> > If we aren't at the outer limits, you can see them from here :) >> > >> > The different levels of boxing actually have different selection >> methods. The best explanation I have seen is Henry Rich's "J for C >> Programmers - Chapter 17" >> http://www.jsoftware.com/help/jforc/more_verbs_for_boxes.htm#_Toc1917 >> 34399 >> > >> > Hope this helps. >> > >> > Cheers, bob >> > >> >> >> -- >> (B=) >> --------------------------------------------------------------------- >> - For information about J forums see >> http://www.jsoftware.com/forums.htm >> > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
