I recently discovered interactive Lisp mode in emacs - M-ielm - so I answered my own question about how Lisp does more generalized reduction - e.g. with a non-commutative (non-associative) verb like minus. Unfortunately, it incorporates the less interesting left-to-right order of evaluation.
ELISP> (+ 2 3) 5 ELISP> (+ 2 3 5 10) 20 ELISP> (- 2 3 5 10) -16 ELISP> (- 2 3) -1 ELISP> (- 2 3 4) -5 ELISP> (- 2 3 4 5) -10 On Wed, Jul 4, 2012 at 2:43 PM, Raul Miller <[email protected]> wrote: > On Wed, Jul 4, 2012 at 2:33 PM, Brian Schott <[email protected]> wrote: >> Lisp is pretty foreign to me, but I wonder about how to mimic Lisp's >> postfix (I hope that's the right term for something like "sum(3 2)" if >> that is actually Lisp syntax)? > > Lisp syntax is: > > (sum 3 2) > > The equivalent J expression would be: > > +/3 2 > > I think you're getting at the issue of lisp argument passing? If so, > I can try spelling out what I was trying to say about it. > > -- > Raul > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- Devon McCormick, CFA ^me^ at acm. org is my preferred e-mail ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
