elisp片段（3）--CPP中文件与实现文件之间的切换

(defun switch-extension(extension)
(if (or (string-equal extension "h") (string-equal extension "hpp"))
"cpp"
"h"))
(defun switch-file-name-extension(name)
(concat (file-name-sans-extension name) "." (switch-extension (file-name-extension name))))
(defun switch-directory (directory)
(cond ((string-match ".+/src/$" directory)
(replace-regexp-in-string "/src/$" "/inc/" directory))
((string-match ".+/inc/$" directory)
(replace-regexp-in-string "/inc/$" "/src/" directory))
(t directory)))
(defun switch-file-path(file-path)
(let ((extension (file-name-extension file-path)) (switched-file-path))
(setf switched-file-path (concat (file-name-sans-extension file-path) "." (switch-extension extension)))
(when (not (file-exists-p switched-file-path))
(setf switched-file-path (concat (switch-directory (file-name-directory switched-file-path)) (file-name-nondirectory switched-file-path))))
switched-file-path))
(defun switch-head-body(file-path)
"切换头文件和实现文件"
(find-file (switch-file-path file-path)))
(defun switch-current-file()
"当前文件在头/实现文件之间切换"
(interactive)
(switch-head-body (buffer-file-name)))