[Maxima-discuss] Reversing the result of dim-* functions in the right way: some progress

[Eduardo O. <edu...@gm...>]

Hi all,

yesterday I sent this message -
  https://sourceforge.net/p/maxima/mailman/message/59245215/
about tricks to understand the display functions...

I just wrote something slightly better.
If I run this in Maxima

  load("/tmp/dim-save.lisp");
  a^b;
  a^bc;
  ab^cd;
  ab^(cd^ef);
  ab^(cd^(ef[gh]));
  :lisp (dim-show)

I get this output:

  (%i1) load("/tmp/dim-save.lisp")$
  (%i2) a^b;
                                         b
  (%o2)                                 a
  (%i3) a^bc;
                                         bc
  (%o3)                                 a
  (%i4) ab^cd;
                                         cd
  (%o4)                                ab
  (%i5) ab^(cd^ef);
                                          ef
                                        cd
  (%o5)                               ab
  (%i6) ab^(cd^(ef[gh]));
                                         ef
                                           gh
                                       cd
  (%o6)                              ab
  (%i7) :lisp (dim-show)
  (REV-OUT (( % o 2 )   (0 0) a (0 1 b)))
  (REV-OUT (( % o 3 )   (0 0) a (0 1 b c)))
  (REV-OUT (( % o 4 )   (0 0) a b (0 1 c d)))
  (REV-OUT (c d (0 1 e f)))
  (REV-OUT (( % o 5 )   (0 0) a b (0 1 c d (0 1 e f))))
  (REV-OUT (c d (0 2 (0 0 e f) (0 -1 g h))))
  (REV-OUT (( % o 6 )   (0 0) a b (0 1 c d (0 2 (0 0 e f) (0 -1 g h)))))
  NIL
  (%i7)

Here is dim-save.lisp:

cat > /tmp/dim-save.lisp <<'%%%'
(defvar dim-saved)

(setq dim-saved nil)

(defun dim-save (&rest plist)
  (setq dim-saved `(,@dim-saved ,(copy-tree plist)))
  plist)

(defun dim-show ()
  (let ((*print-pretty* nil))
    (loop for plist in dim-saved
 do (format t "~a~%" plist))))

(defun my-reverse-nnlist (abcd)
  (let* ((a (car abcd))
(b (cadr abcd))
(cd (cddr abcd)))
    `(,a ,b ,@(my-reverse cd))))

(defun my-reverse-otherlist (list)
  (reverse (mapcar #'my-reverse list)))

(defun my-reverse (o)
  (if (listp o)
      (if (numberp (car o))
 (my-reverse-nnlist o)
 (my-reverse-otherlist o))
      o))

;; `dimension-superscript-saving-1' saves a lot of information.
;; `dimension-superscript-saving-2' saves just the essential.

(defun dimension-superscript-saving-1 (form result)
  (dim-save :pos 1 :form form :result result)
  (let ((out (dimension-superscript form result)))
    (dim-save :pos 2 :form form :result result :out out)
    out))

(defun dimension-superscript-saving-2 (form result)
  (let ((out (dimension-superscript form result)))
    (dim-save :rev-out (my-reverse out))
    out))

(displa-def mexpt  dimension-superscript-saving-2)
(displa-def %mexpt dimension-superscript-saving-2)
%%%

  Cheers,
    Eduardo