在emacs中从camelcase转换为_

Question

是否有emacs函数将驼峰式单词转换为下划线？就像是：

longVariableName

M-x to-underscore

long_variable_name

Answer 1

(progn (replace-regexp "\\([A-Z]\\)" "_\\1" nil (region-beginning) (region-end))
       (downcase-region (region-beginning) (region-end)))

Answer 2

使用MELPA或https://github.com/akicho8/string-inflection上提供的string-inflection包。

从https://www.emacswiki.org/emacs/CamelCase复制的有用键盘快捷键：

;; Cycle between snake case, camel case, etc.
(require 'string-inflection)
(global-set-key (kbd "C-c i") 'string-inflection-cycle)
(global-set-key (kbd "C-c C") 'string-inflection-camelcase)        ;; Force to CamelCase
(global-set-key (kbd "C-c L") 'string-inflection-lower-camelcase)  ;; Force to lowerCamelCase
(global-set-key (kbd "C-c J") 'string-inflection-java-style-cycle) ;; Cycle through Java styles

Answer 3

我使用以下内容在camelcase和underscores之间切换：

(defun toggle-camelcase-underscores ()
  "Toggle between camelcase and underscore notation for the symbol at point."
  (interactive)
  (save-excursion
    (let* ((bounds (bounds-of-thing-at-point 'symbol))
           (start (car bounds))
           (end (cdr bounds))
           (currently-using-underscores-p (progn (goto-char start)
                                                 (re-search-forward "_" end t))))
      (if currently-using-underscores-p
          (progn
            (upcase-initials-region start end)
            (replace-string "_" "" nil start end)
            (downcase-region start (1+ start)))
        (replace-regexp "\\([A-Z]\\)" "_\\1" nil (1+ start) end)
        (downcase-region start (cdr (bounds-of-thing-at-point 'symbol)))))))

Answer 4

我在将C＃代码转换为PHP时使用它。

(defun un-camelcase-word-at-point ()
  "un-camelcase the word at point, replacing uppercase chars with
the lowercase version preceded by an underscore.

The first char, if capitalized (eg, PascalCase) is just
downcased, no preceding underscore.
"
  (interactive)
  (save-excursion
    (let ((bounds (bounds-of-thing-at-point 'word)))
      (replace-regexp "\\([A-Z]\\)" "_\\1" nil
                      (1+ (car bounds)) (cdr bounds))
      (downcase-region (car bounds) (cdr bounds)))))

然后在我的php模式fn中：

(local-set-key "\M-\C-C"  'un-camelcase-word-at-point)

Answer 5

现在有另一种通用的方式在2018年：magnars/s.el: The long lost Emacs string manipulation library. - github.com，关于OP问题的一些例子：

1. 无论是什么情况下蛇案（下划线分开）： qazxsw poi
2. 无论如何降低骆驼案例：

   (s-snake-case "some words") ;; => "some_words"
   (s-snake-case "dashed-words") ;; => "dashed_words"
   (s-snake-case "camelCasedWords") ;; => "camel_cased_words"

在其回购中查看更多示例。