在elisp中编译变量

Question

如何在elisp中编译函数调用的结果变量？是需要在所有变量的主体中添加一个eval-when-compile，还是有什么方法可以确保相同的结果，而不需要在所有变量定义中重写呢？

用例是编译我在机器之间变化的局部变量。例如,

(defun setup-defaults (loc)
  (when (eq system-type 'windows-nt)
    (cond
     ((file-exists-p (expand-file-name loc "~"))
      (file-name-as-directory (expand-file-name loc "~")))
     ((file-exists-p (expand-file-name loc "d:/"))
      (file-name-as-directory (expand-file-name loc "d:/"))))))

(defconst my/org (setup-defaults "org"))

(defconst my/home
  (eval-when-compile
    (file-name-directory
     (file-chase-links (or load-file-name "~/.emacs.d/init.el")))))

变量my/home将被编译为"~/.emacs.d/“，但除非我将其重写为

(defconst my/org (eval-when-compile (setup-defaults "org")))

那么，对于我所有的变量，我需要这样做吗？

Answer 1

啊，算了吧，这就是宏的作用，只用defmacro就可以解决这个问题，

(defmacro setup-defaults (loc)
  (when (eq system-type 'windows-nt)
    (cond
     ((file-exists-p (expand-file-name loc "~"))
      (file-name-as-directory (expand-file-name loc "~")))
     ((file-exists-p (expand-file-name loc "d:/"))
      (file-name-as-directory (expand-file-name loc "d:/"))))))