Fix for $matrix (Was: "matrix([matrix([" returned with mat_function (Was: Re: Symbolic matrix power))

How about this?  This defines matrix as a multi-argument *Maxima* function.
 Slight overhead in GCL only.

                    -s


(remprop '$matrix 'mfexpr*)

;;; Define $matrix so that apply(matrix,...) does not need to use Lisp
;;; apply -- in GCL, apply is limited to 63 arguments.

;;; Assume we can't call $define here, but mputprop is defined in
maxmac.lisp

;;; Equivalent to matrix([?rows]) := ?matrixhelper(?rows)$
#+gcl (mputprop '$matrix
'((lambda) ((mlist) ((mlist) rows)) ((matrixhelper) rows))
'mprops)
#+gcl (mputprop '$matrix t 'mlexprp)

#-gcl (defun $matrix (&rest rows) (matrixhelper rows))

;; Call ONLY from $matrix
(defun matrixhelper (rows maximap)
  #+gcl (progn (if (not ($listp rows))
   (merror "matrixhelper expects a Maxima list"))
       (setq rows (cdr rows)))
  (dolist (row rows)
    (if (not ($listp row))
(merror (intl:gettext "matrix: row must be a list; found: ~M") row)))
  (matcheck rows)
  (cons '($matrix) rows))



On Tue, Oct 29, 2013 at 12:38 AM, Stavros Macrakis <macrakis at alum.mit.edu>wrote:

> Hmm.  GCL seems to support 200 arguments in eval, but not in apply:
>
> (defun f (&rest x) x)
> (setq l (do ((i 0 (1+ i)) (l nil (cons i l))) ((> i 200) l)))
> (apply 'f l) => error
> (eval (cons 'f l)) => correct value
>
> I don't think rewriting $matrix can help. Rewriting meval/mapply might
> help, but it would be bizarre to have to wrap all arguments with (quote
> ...), but maybe necessary for > 63 arguments ?!
>
> The best fix would of course be to improve GCL.
>
>                   -s
>
>
> On Mon, Oct 28, 2013 at 11:27 PM, Robert Dodier <robert.dodier at gmail.com>wrote:
>
>> On 2013-10-29, Stavros Macrakis <macrakis at alum.mit.edu> wrote:
>>
>> > (defun $matrix (&rest rows)
>>
>> >> But that only matters if an object is being *evaluated* where it
>> >> shouldn't be. And sure enough, applying the 'matrix' function
>> incorrectly
>> >> re-evaluates its arguments.
>>
>> Excellent catch, spot on. However, the current version of $MATRIX is
>> pretty recent, and it's written as a MFEXPR* because GCL allows only a
>> small number of arguments -- 63 iirc. So it was easy to bump into
>> something like matrix([1], [2], ..., [64]) => Lisp error: too many
>> arguments. For the record: commit 9bcad16b9e.
>>
>> I suppose all Lisps must have a limit on the number of arguments, but
>> aside from GCL, the limit is so big that nobody bumped into it. Is there
>> a way to write $MATRIX which accommodates both a long argument list and
>> ordinary evaluation?
>>
>> best
>>
>> Robert Dodier
>>
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>>
>
>