change-inner.el

(defun change-inner (prefix character)
  "Kill region inside delimiters, using either beginning or
ending delimiter.  With prefix arg, kill including delimiters."

  (interactive "p\nc")
  (let ((initial-point (point))
        (start)
        (end)
        (move-point-by (if (> prefix 1) 0 1)))

    (condition-case nil
        (progn
          ;; Search forward for given char
          (search-forward (char-to-string character))
          (setq end (- (point) move-point-by))

          (condition-case nil
              (backward-sexp)
            (error (backward-list)))

          (setq start (+ (point) move-point-by))
          (kill-region start end)
          (or prefix (forward-char)))

      (error (progn
               ;; Reset and search backward for given char
               (goto-char initial-point)
               (search-backward (char-to-string character))
               (setq start (+ (point) move-point-by))

               (condition-case nil
                   (forward-list)
                 (error (forward-sexp))))

             (setq end (- (point) move-point-by))
             (kill-region start end)
             (or prefix (backward-char))))))

(defun change-outer ()
  (interactive)
  (let ((current-prefix-arg '(4)))
    (call-interactively 'change-inner)))