REPEAT use APPLY with too many arguments, very sub-optimal

[Yehouda]

https://github.com/vindarel/cl-str/blame/f2d52f5490e691dcda132c5f84683cf153090794/str.lisp#L350

The number per chunk should be limited call-argument-list, so the call to apply and concat are with limited number fo arguments. On Lispworks the limit is 20247, so currently you get an error in the test with large count.

Anyway, the code there is very sub-optimal. You really should make the new string in one go, and then copy into it. Something like:

(defun repeat (count string)
  (let ((str-len (length string)))
    (cond  ((= str-len 1)
            (let ((char(char string 0)))
              (make-string count :initial-element char :element-type (type-of char))))
           ((= str-len 0) "")
           (t
            (let* ((full-len (* count str-len))
                   (index 0)
                   (elemet-type (if (typep string 'base-string) ; maybe always make it character
                                    'base-char
                                  'character))
                   (full-string (make-string full-len :element-type elemet-type )))
              (dotimes (x count)
                (replace full-string string :start1 index)
                (incf index str-len))
              full-string)))))

I didn't test this on many cases.

[vindarel]

Isn't the apply used with max 10 000 elements?

But thanks, I'll look at your improvement suggestions.

[Yehouda]

I mistyped the number. In lispWorks it is 2047 (not 20247).