如何使用行+文件引用从emacs缓冲区复制/粘贴区域

Question

我不时看到人们根据文件名和行号粘贴部分代码。类似的东西

 ;; ----- line:3391   file: simple.el.gz -----;;; 
 (if (eq last-command 'kill-region)
      (kill-append (filter-buffer-substring beg end) (< end beg))
    (kill-new (filter-buffer-substring beg end)))
 ;; ----- line:3394 --------------------------;;;

这对于通过邮件发送对代码的评论非常有用。我可以很容易地为自己包装一个简单的函数，但我相信有人已经用一种聪明而漂亮的方式做到了这一点。

谢谢。

[编辑]

因为这个功能只是偶尔需要的，而且只用于一次复制/粘贴操作，所以我最终使用了@thisir提出的切换版本的替代解决方案。

(defun kill-with-linenum (beg end)
  (interactive "r")
  (save-excursion
    (goto-char end)
    (skip-chars-backward "n t")
    (setq end (point))
    (let* ((chunk (buffer-substring beg end))
           (chunk (concat
                   (format "╭──────── #%-d ─ %s ──n│ "
                           (line-number-at-pos beg)
                           (or (buffer-file-name) (buffer-name))
                           )
                   (replace-regexp-in-string "n" "n│ " chunk)
                   (format "n╰──────── #%-d ─" 
                           (line-number-at-pos end)))))
      (kill-new chunk)))
  (deactivate-mark))

它是基于unicode的，并产生以下输出：

╭──────── #3557 ─ /usr/share/emacs/24.1.50/lisp/simple.el.gz ──
│   (if (eq this-command t)
│       (setq this-command 'yank))
│   nil)
╰──────── #3559 ─

Answer 1

我已经使用包装器挂钩：

(defun filter-buffer-substring-add-line (func beg end delete)
  (concat
   (format ";; line:%5d file: %sn"
           (line-number-at-pos beg)
           (or (buffer-file-name) (buffer-name)))
   (funcall func beg end delete)
   (format "n;; line:%5d" (line-number-at-pos end))))
(defun kill-add-line-toggle ()
  (interactive)
  (if (memq 'filter-buffer-substring-add-line
            filter-buffer-substring-functions)
      (progn
        (setq filter-buffer-substring-functions
              (delq 'filter-buffer-substring-add-line
                    filter-buffer-substring-functions))
        (message "Add line is off!"))
    (push 'filter-buffer-substring-add-line
          filter-buffer-substring-functions)
    (message "Add line is on!")))