narrow-to-list.el

(defun matching-char (find other delta &optional start level)
  (save-excursion
    (let ((level (if level level 0))
	  (start (if start start (point))))
      (if (and
	   start
	   (>= start (point-min))
	   (<= start (point-max)))
	  (goto-char start)
	(error "Not within block"))
      
      (cond
       ((looking-at find)
	(if (= level 0)
	    (point)
	  (matching-char find other delta (+ start delta) (- level 1)))
	)
       ((looking-at other)
	(matching-char find other delta (+ start delta) (+ level 1)))
       (t
	  (matching-char find other delta (+ start delta) level)
	)
       ))))

(defun kill-block ()
  "Kills the brace-delimited block which the point is currently within."
  (interactive)
  (kill-region (matching-char "{" "}" -1)
	       (+ 1 (matching-char "}" "{" 1))))