read-number function missing in emacs21?

[David Coe]

Hi Bob, or anyone else who knows:

One of the chnages between 4.07 and 4.08
replaced (in br-env.el)

  (string-to-int
    (read-string (concat lang-prompt ": ") ""))))

with

  (read-number (concat lang-prompt ": ") t)))

but under emacs21, at least, read-string is
not defined.  Where should that come from?

Reverting the above change seems to work.

Thanks.

[Christopher Smith]

I'm having this exact same problem, and I'm noticing that this is far from the only place where read-string exists.

[Magnus Hulthén]

The read-number function is defined in XEmacs and not in Emacs.

If you place the following code (stolen from XEmacs) in your .emacs file you should be OK.

(defun read-number (&optional prompt default)
  "Read a number from the minibuffer.
Optional arguments: PROMPT DEFAULT.

If DEFAULT is non-nil, it is written within parenthesis after the prompt.
DEFAULT can be either a number, or of the type which `(interactive P)'
generates."
  (let ((numdefault (cond ((null default) nil)
              ((integerp default) default)
              ((listp default) (car default))
              (t nil)))
    (number nil)
    (numstr nil))

    (while (not number)
      (setq numstr (read-string
            (concat (if prompt
                prompt
                  "Enter a number: ")
                (if numdefault
                (format "(%d) " numdefault)))))
      (cond ((and (string= numstr "")
          numdefault)
         (setq number numdefault))
        ((string-match "\\`[0-9]+\\'" numstr)
         (setq number (string-to-int numstr)))
        (t (beep))))
    number))