Emacs 缩进难度

Question

我真的很想改用 emacs，但是学习设置环境真的很痛苦。 每个人都说值得，所以我继续。

我希望我的 c 代码以这种方式实现：

if(asdf)
{
    asdr = 1;
}

根据当前标准（我知道，不要让我开始），可能是：

if(asdf) {
    asdr = 1;
}

我似乎无法从 2 更改缩进大小，它总是看起来像 GNU 标准：

if(asdf)
  {
    asdr = 1;
  }

，我不喜欢。 这是我在 .emacs 中添加的内容：

; Warn in C for while();, if(x=0), ...
(global-cwarn-mode 1)

; no electric mode in c
(c-toggle-electric-state -1)
; indent the current line only if the cursor is at the beginning of the line
(setq-default c-tab-always-indent nil)
(setq-default c-indent-level 4)
(setq-default tab-width 4)
(setq-default indent-tabs-mode nil)
(setq-default c-basic-offset 4)
(setq-default c-basic-indent 4)
; These commands I read about on the web, but they don't work?
;(highlight-tabs)
;(highlight-trailing_whitespace)

这没有帮助，我仍然有 GNU 缩进。 有人吗？

--- 编辑以添加我的整个 .emacs（实际上是 ~/.emacs.d/init.el）

; directory to put various el files into
(add-to-list 'load-path "C:/Program/emacs-22.3/includes")

; loads ruby mode when a .rb file is opened.
(autoload 'ruby-mode "ruby-mode" "Major mode for editing ruby scripts." t)
(setq auto-mode-alist  (cons '(".rb$" . ruby-mode) auto-mode-alist))
(setq auto-mode-alist  (cons '(".rhtml$" . html-mode) auto-mode-alist))

(add-hook 'ruby-mode-hook
          (lambda()
            (add-hook 'local-write-file-hooks
                      '(lambda()
                         (save-excursion
                           (untabify (point-min) (point-max))
                           (delete-trailing-whitespace)
                           )))
            (set (make-local-variable 'indent-tabs-mode) 'nil)
            (set (make-local-variable 'tab-width) 2)
            (imenu-add-to-menubar "IMENU")
            (define-key ruby-mode-map "\C-m" 'newline-and-indent) ;Not sure if this line is 100% right but it works!
            (require 'ruby-electric)
            (ruby-electric-mode t)
            ))

; Install mode-compile to give friendlier compiling support!
(autoload 'mode-compile "mode-compile"
   "Command to compile current buffer file based on the major mode" t)
(global-set-key "\C-cc" 'mode-compile)
(autoload 'mode-compile-kill "mode-compile"
 "Command to kill a compilation launched by `mode-compile'" t)
(global-set-key "\C-ck" 'mode-compile-kill)


(show-paren-mode 1)

; Color theme
(require 'color-theme)
(color-theme-pok-wog)
;;Emacs.pane.menubar.* does not seem to work? 
;Emacs.pane.menubar.background: darkGrey
;Emacs.pane.menubar.foreground: black


; Default font 9 pt
(set-face-attribute 'default nil :height 80)

(custom-set-variables
  ;; custom-set-variables was added by Custom.
  ;; If you edit it by hand, you could mess it up, so be careful.
  ;; Your init file should contain only one such instance.
  ;; If there is more than one, they won't work right.
 )
(custom-set-faces
  ;; custom-set-faces was added by Custom.
  ;; If you edit it by hand, you could mess it up, so be careful.
  ;; Your init file should contain only one such instance.
  ;; If there is more than one, they won't work right.
 '(font-lock-comment-face ((t (:foreground "limegreen" :slant oblique))))
 '(font-lock-preprocessor-face ((t (:inherit font-lock-builtin-face :foreground "orange" :weight bold)))))


(global-set-key [C-tab] 'other-window)
(global-set-key [C-S-tab] (lambda () (interactive) (other-window -1)))

(defun linux-c-mode ()
  "C mode with adjusted defaults for use with the Linux 
kernel."
  (interactive)
  (c-mode)
  (setq c-indent-level 8)
  (setq c-brace-imaginary-offset 0)
  (setq c-brace-offset -8)
  (setq c-argdecl-indent 8)
  (setq c-label-offset -8)
  (setq c-continued-statement-offset 8)
  (setq indent-tabs-mode nil)
  (setq tab-width 8))


; Warn in C for while();, if(x=0), ...
(global-cwarn-mode 1)

; no electric mode in c
(c-toggle-electric-state -1)
; indent the current line only if the cursor is at the beginning of the line
(setq-default c-tab-always-indent nil)
(setq-default c-indent-level 4)
(setq-default tab-width 4)
(setq indent-tabs-mode nil)
(setq-default c-basic-offset 4)
(setq-default c-basic-indent 4)
; These commands I read about on the web, but they don't work?
;(highlight-tabs)
;(highlight-trailing_whitespace)
(setq indent-tabs-mode nil)
(setq c-default-style "user")


;; Remove lull: scroll bar, tool bar, menu bar.
(if (fboundp 'scroll-bar-mode) (scroll-bar-mode -1))
(if (fboundp 'tool-bar-mode) (tool-bar-mode -1))
(if (fboundp 'menu-bar-mode) (menu-bar-mode -1))


;; restore window size as it was at previous use
(defun restore-saved-window-size()
  (unless (load "~/.emacs.d/whsettings" t nil t)
    (setq saved-window-size '(80 30)))
  (nconc default-frame-alist `((width . ,(car saved-window-size))
                   (height . ,(cadr saved-window-size)))))

(restore-saved-window-size)

(defun save-window-size-if-changed (&optional unused)
  (let ((original-window-size  `(,(frame-width) ,(frame-height))))
    (unless (equal original-window-size saved-window-size)
      (with-temp-buffer
        (setq saved-window-size original-window-size) 
        (insert (concat "(setq saved-window-size '"
                        (prin1-to-string saved-window-size) ")"))
        (write-file "~/.emacs.d/whsettings")))))

(add-hook 'window-size-change-functions 'save-window-size-if-changed)

;; Ack as a replacment for grep
(global-set-key "\M-s" 'ack)
(require 'ack)

Answer 1

EmacsWiki 在IndentingC 上有一篇不错的文章。

事实上，EmacsWiki 对所有内容都有很好的文章。我不想在 Emacs 出现之前就学习它。

Answer 2

emacs cc-mode 中的缩进由一组偏移量控制，每个偏移量都可以根据附加到偏移量的名称进行设置。

if 语句后的左花括号有一个偏移量，带有一个名称。如果更改偏移值，则开卷曲的缩进会有所不同。同样，函数声明后的开卷曲也有一个命名的偏移量。宏中的续行有一个命名的偏移量。 switch 语句中的 case 标签，执行 while 循环。它们都有偏移量。有无数个，全部存储在一个名为 c-offsets-alist 的变量中。

其他地方提到的样式提供了一个“基本偏移量”，通常是 2、4 或 8 个空格，然后是 c-offsets-alist 的值。每种样式也有一个名称，您可以从其他样式派生自定义样式。像这样：

(c-add-style "myCStyle"
  '("bsd"  ; this must be defined elsewhere - it is in cc-modes.el
  (c-basic-offset . 4)
  (c-echo-syntactic-information-p . t)
  (c-comment-only-line-offset . (0 . 0))
  (c-offsets-alist . (
    (c                     . c-lineup-C-comments)
    (statement-case-open   . 0)
    (case-label            . +)
    (substatement-open     . 0)
    ))
  ))

c-offsets-alist 中每个命名偏移的值是以下之一：

• 0 暗示，保持与上一行相同的缩进
• + 暗示，增加缩进，增加一级
• - 暗示，减少缩进，增加一级

您还可以使用 ++、-- 等。在您的 .emacs 文件中放置类似的内容以定义样式。然后，要在编辑 C 文件时自动使用该样式，请在 c 模式挂钩中使用 c-set=style，如下所示：

(defun doug-c-mode-hook-fn ()
  (cond (window-system
     ;; use my defined style for all C modules
     (c-set-style "myCStyle")
     ;; never convert leading spaces to tabs
     (setq indent-tabs-mode nil)
       ....
  )))

(add-hook 'c-mode-hook 'doug-c-mode-hook-fn)

下一个问题是，如何确定您需要为任何特定情况设置哪些命名的 c 偏移量？有一个应用程序。好的，不是应用程序，而是 elisp 函数。

M-x c-set-offset
显示 emacs 在语法上认为它在 cc-mode 源文件中的位置。要使用它， 将光标放在您想了解偏移名称的位置，或更改偏移。然后调用这个函数。它会告诉您当前句法元素的偏移量的名称。
如果您在 c-offsets-alist 中为您选择的样式更改该命名元素的值，这通常在 .emacs 或等效文件中完成，那么缩进 所有源模块的设置都为真。

Answer 3

cc-mode 的样式功能可能会覆盖您的默认设置。

尝试像这样初始化默认样式：

(setq c-default-style '((java-mode . "java") (awk-mode . "awk") (other . "user")))

您应该能够将前一行粘贴到您的 .emacs 文件中，或者自定义 c-default-style 变量。默认将(other "gnu") 作为列表的最后一个元素，这意味着所有非Java 和非awk 文件都获得gnu 样式，而不是您使用setq 设置的样式。特殊的 user 样式从您手动设置的样式变量中初始化。

另一种选择是选择一种内置样式而不是自己定义，或者使用c-add-style 函数创建自己的样式。为此，请将上述命令中的 "user" 更改为样式的名称（作为字符串）。尝试使用 stroustrup 或 python 内置样式来格式化你想要的 if 语句。