[Emacs Tips] 插入相邻一行的字符

类似于 VIM 插入状态下的 C-y 和 C-e，也就是插入光标所在上一行或者下一行的字符。
例如： VIM 插入状态下的 C-y 和 C-e，也就是插入光标所在上一行或者下一行的字符。

写程序的时候还是挺有用的

;;;###autoload
(defun my-insert-char-next-line (arg)
  "insert char below the cursor"
  (interactive "p")
  (let ((col (current-column))
        char)
    (setq char
          (save-excursion
            (forward-line arg)
            (move-to-column col)
            (if (= (current-column) col)
                (char-after))))
    (if char
        (insert-char char 1)
      (message (concat "Can't get charactor in "
                       (if  (< arg 0)
                           "previous"
                         "next")
                       (progn (setq arg (abs arg))
                              (if (= arg 1) ""
                                (concat " " (number-to-string arg))))
                       " line.")))))

;;;###autoload
(defun my-insert-char-prev-line (arg)
  "insert char above the cursor"
  (interactive "p")
  (my-insert-char-next-line (- arg)))

用的键绑定是 C-x ( 和 C-x )

(global-set-key (kbd "C-)") 'my-insert-char-next-line)
(global-set-key (kbd "C-(") 'my-insert-char-prev-line)