Implementation-indpendent string-unless-number

[Yehouda]

gadgets:string-unless-number currently uses conditionalization, which limits where it works. I think the following code would do what is required using onlu common-lisp:

(defun string-unless-number (x)
  "Return the input as a string unless it can be recognized as an integer."
  (if (numberp x)
      x
    (if (stringp x)
        (or (ignore-errors (parse-integer x)) x)
      (error "STRING-UNLESS-NUMBER: argument is not a number or a string : ~s" x))))

[BnMcGn]

Thanks! Fix committed.