emacs - 在保存某些文件类型(并且仅这些文件类型)时让 Emacs 取消制表符

Question

我的 .emacs 文件中有以下内容:

 (defun c++-mode-untabify ()
   (save-excursion
     (goto-char (point-min))
     (while (re-search-forward "[ \t]+$" nil t)
       (delete-region (match-beginning 0) (match-end 0)))
     (goto-char (point-min))
     (if (search-forward "\t" nil t)
         (untabify (1- (point)) (point-max))))
   nil)

 (add-hook 'c++-mode-hook
           '(lambda ()
              (make-local-hook 'write-contents-hooks)
              (add-hook 'write-contents-hooks 'c++-mode-untabify)))

大部分来自 http://www.jwz.org/doc/tabs-vs-spaces.html .这会导致 emacs 运行 untabify在保存 C++ 文件之前在缓冲区上。

问题是在我加载了一个 C++ 文件后， untabify钩子(Hook)被应用到 全部 后续文件写入，即使是其他文件类型的缓冲区。这意味着，如果我打开一个 C++ 文件，然后编辑一个制表符分隔的文本文件，则在保存文件时制表符会被破坏。

我不是 elisp 大师，但我认为 (make-local-hook 'write-contents-hooks)行正在尝试添加到 write-contents-hooks仅适用于本地缓冲区。但是，它不起作用，并且 c++-mode-untabify在 write-contents-hooks对于所有缓冲区。

我在 Windows XP 机器上使用 EmacsW32 22.0。有谁知道如何制作 write-contents-hooks将本地更改为特定缓冲区或如何将其重置为 nil切换到其他非 C++ 缓冲区时？

Answer 1

write-contents-hooks 也已过时。这就是你所追求的:

(add-hook 'c++-mode-hook
      '(lambda ()
         (add-hook 'before-save-hook
                   (lambda ()
                     (untabify (point-min) (point-max))))))

这是从我使用的东西中提炼出来的，它做了一些其他的事情，并被抽象出来以使用特定于编程的模式:

(defun untabify-buffer ()
  "Untabify current buffer"
  (interactive)
  (untabify (point-min) (point-max)))

(defun progmodes-hooks ()
  "Hooks for programming modes"
  (yas/minor-mode-on)
  (add-hook 'before-save-hook 'progmodes-write-hooks))

(defun progmodes-write-hooks ()
  "Hooks which run on file write for programming modes"
  (prog1 nil
    (set-buffer-file-coding-system 'utf-8-unix)
    (untabify-buffer)
    (copyright-update)
    (maybe-delete-trailing-whitespace)))

(defun delete-trailing-whitespacep ()
  "Should we delete trailing whitespace when saving this file?"
  (save-excursion
    (goto-char (point-min))
    (ignore-errors (next-line 25))
    (let ((pos (point)))
      (goto-char (point-min))
      (and (re-search-forward (concat "@author +" user-full-name) pos t) t))))

(defun maybe-delete-trailing-whitespace ()
  "Delete trailing whitespace if I am the author of this file."
  (interactive)
  (and (delete-trailing-whitespacep) (delete-trailing-whitespace)))

(add-hook 'php-mode-hook 'progmodes-hooks)
(add-hook 'python-mode-hook 'progmodes-hooks)
(add-hook 'js2-mode-hook 'progmodes-hooks)