Re: elisp question

[Kevin Rodgers]

harven wrote:
> I am trying to device a short command to
> interactively resize the current window:
>
> (defun resize-window (key)
>  "resize interactively the window"
>  (interactive "c- widen, _ shrink")
>    (cond
>      ((eq key (string-to-char "-"))
>         (enlarge-window 1)
>         (call-interactively 'resize-window))
>      ((eq key (string-to-char "_"))
>         (enlarge-window -1)
>         (call-interactively 'resize-window))
>      (t (insert key))))
>
> I type -/_ a number of times, the window enlarges/shrinks, and if I
> type another character, the window resizing stops and the character is
> inserted.
>
> However, I would like the following effect.
> Any entry other than -/_ should end the resizing and be executed. How
> can I achieve such effect ?

See the unread-command-events variable.  Here's an iterative version to
compare to your recursive implementation:

(defvar enlarge-window-char ?_)         ; or ?+
(defvar shrink-window-char ?-)

(defun resize-window (&optional arg)
  "Interactively resize the selected window.
Repeatedly prompt whether to enlarge or shrink the window until the
response is neither `enlarge-window-char' or `shrink-window-char'.
When called with a prefix arg, resize the window by ARG lines."
  (interactive "p")
  (let ((prompt (format "Enlarge/Shrink window (%c/%c)? "
                        enlarge-window-char shrink-window-char))
        response)
    (while (progn
             (setq response (read-event prompt))
             (cond ((equal response enlarge-window-char)
                    (enlarge-window arg)
                    t)
                   ((equal response shrink-window-char)
                    (enlarge-window (- arg))
                    t)
                   (t nil)))
      ;; no loop body needed
      )
    (push response unread-command-events)))



--
Kevin Rodgers
Denver, Colorado, USA