在 Emacs 中恢复垂直缓冲区位置答案

【问题标题】：Restore vertical buffer position in Emacs在 Emacs 中恢复垂直缓冲区位置
【发布时间】：2013-11-27 16:34:28
【问题描述】：

我有以下代码，我使用这些代码更新了我正在使用的一些遗留代码的编码样式。它现在可以正常工作，但是令人讨厌的是，在区域上执行命令后，缓冲区会滚动，因此该区域的顶部位于窗口的顶部。我该如何解决这个问题？

(defun mkm/cleanup ()
  (interactive)
  (let (start end doit)
    (if (region-active-p)
        (setq start (region-beginning) end (region-end) doit t)
      (progn (setq start (point-min) end (point-max))
             (setq doit (y-or-n-p "Really cleanup whole buffer? "))))
    (if doit
        (save-excursion
          (save-restriction
            (narrow-to-region start end)
            (replace-regexp "\([[:alpha:]]\)[ ]+" "\1 " nil (point-min) (point-max))
            (replace-regexp " *&" " &" nil (point-min) (point-max))
            (replace-regexp "[ ]*\\*" " *" nil (point-min) (point-max))
            (replace-regexp "( +" "(" nil (point-min) (point-max))
            (replace-regexp " +)" ")" nil (point-min) (point-max))
            (replace-regexp "{ +" "{" nil (point-min) (point-max))
            (replace-regexp "} +" "}" nil (point-min) (point-max))
            (replace-regexp " +]" "]" nil (point-min) (point-max))
            (replace-regexp "\s*,\s*" ", " nil (point-min) (point-max))
            (replace-regexp "\s*->\s*" "->" nil (point-min) (point-max))
            (replace-regexp "\\[ +" "\\[" nil (point-min) (point-max))
            (replace-regexp " += +" " = " nil (point-min) (point-max))
            (replace-regexp "\([[:alpha:]]\)[ ]+>" "\1>" nil (point-min) (point-max))
            (replace-regexp "<\s+" "<" nil (point-min) (point-max))
            (replace-regexp "<<\([^\s]\)" "<< \1" nil (point-min) (point-max))))
      (message "Cleanup aborted."))))

【问题讨论】：

标签： regex emacs elisp

【解决方案1】：

这是代码，相关函数是save-window-excursion。

(defun mkm/cleanup ()
  (interactive)
  (let (start end doit)
    (if (region-active-p)
        (setq start (region-beginning)
              end (region-end)
              doit t)
      (setq start (point-min)
            end (point-max)
            doit (y-or-n-p "Really cleanup whole buffer? ")))
    (if doit
        (save-window-excursion
          (save-excursion
            (save-restriction
              (narrow-to-region start end)
              (mapc
               (lambda(x)
                 (replace-regexp
                  (car x) (cdr x)
                  nil (point-min) (point-max)))
               '(("\([[:alpha:]]\)[ ]+" . "\1 ")
                 (" *&" . " &")("[ ]*\\*" . " *")
                 ("( +" . "(")(" +)" . ")")("{ +" . "{")
                 ("} +" . "}")(" +]" . "]")("\s*,\s*" . ", ")
                 ("\s*->\s*" . "->")("\\[ +" . "\\[")
                 (" += +" . " = ")
                 ("\([[:alpha:]]\)[ ]+>" . "\1>")
                 ("<\s+" . "<")("<<\([^\s]\)" . "<< \1"))))))
      (message "Cleanup aborted."))))

【讨论】：

太好了，成功了！我认为您的意思是 save-window-excursion 是相关功能。感谢您提出重构的建议，我认为这样会更好:)

【解决方案2】：

不要使用save-excursion？ save-excursion 说，“做这件事，然后回到这里。”听起来您希望它改为“做这些事情，并保持在最终的位置。”

【讨论】：

【解决方案3】：

您可能只需要：

(let ((windowstart (window-start)))
  ;; ...
  (set-window-start (selected-window) windowstart))

【讨论】：