保存某些文件类型(并且只保存那些文件类型)时让Emacs解除保护

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)))

大部分都是从http://www.jwz.org/doc/tabs-vs-spaces.html中删除的.这会导致emacs untabify在保存C++文件之前在缓冲区上运行.

问题是,在我加载了C++文件之后,untabify钩子正被应用于所有后续文件写入,即使对于其他文件类型的缓冲区也是如此.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,那么在保存文件时这些选项卡会被破坏.

我不是一个elisp大师,但我认为该(make-local-hook 'write-contents-hooks)行试图使添加write-contents-hooks仅适用于本地缓冲区.但是,它不起作用,并且c++-mode-untabify适用于write-contents-hooks所有缓冲区.

我在Windows XP机器上使用EmacsW32 22.0.有没有人知道如何在write-contents-hooks特定缓冲区本地进行更改或如何nil在切换到其他非C++缓冲区时将其重置为？

Answer 1

write-contents-hooks也已经过时了.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,它还做了一些其他事情,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)

Answer 2

我的Emacs中的文档说自从21.1开始,make-local-hook现在已经过时了,因为add-hook现在需要一个可选的参数来创建一个hook buffer-local.所以你可以尝试:

(add-hook 'c++-mode-hook
           '(lambda ()
              (add-hook 'write-contents-hooks 'c++-mode-untabify nil t)))

另一种选择是让c ++ - mode-untabify函数检查当前模式.我可能只是写这样的东西:

(defun c++-mode-untabify ()
  (if (string= (substring mode-name 0 3) "C++")
      (save-excursion
       (delete-trailing-whitespace)
       (untabify (point-min) (point-max)))))