;;;----------------------str2num.lsp-------------------
;;;converts a string representing a number into a real or integer
;;;----------------------------------------------------
(defun str2num (str / chlst)
  (cond
    ((member (type str) '(INT REAL)) str);is a number, so return it
    ((= (type str) 'STR)
     (progn
       (setq chlst (vl-string->list str))
       (if (member nil
                   (mapcar
                     (function (lambda (x)
                                 (and (/= x 47)
                                      (> 58 x 44)
                                 )
                               )
                     )
                     chlst
                   )
           )
         nil ; the string does not represent a number
         (if (member 46 chlst) ;contains a decimal point
           (atof str) ;real
           (atoi str) ;integer
         );if
       );if
     );progn
    )
    ((= (type str) 'SYM) (str2num (eval str)));recurse on evaluated arg
    (T nil);not a number or a string which represents a number
  )
);str2num