调用带引号的def宏

Question

我有这样的数据结构(基本上)：

(setq ssm-list '(tasklist
  ((id . "10525295")
   (name . "Inbox")
   (sort_order . "0"))))

这适用于获取名称：

(defun ssm-list-get-prop (list prop)
  (cdr (assoc prop (car (cdr list)))))

(ssm-list-get-prop slack-one-list 'name)

我想要的是创建一个宏，它将创建一个名称为ssm-list-name (或ssm-list-id)的defun，因为列表中实际上有更多的属性。

所以我试了一下：

(defmacro ssm-list-prop-defun (field)
  `(defun ,(intern (concat "ssm-list-" field))
      (one-list)
      (cdr (assoc ,field (car (cdr one-list))))))

(ssm-list-prop-defun 'name)
(ssm-list-prop-defun 'id)

但是最后两次调用(wrong-type-argument characterp quote)都失败了，我试着把symbol-name放在宏里，但是没有用。

有没有办法做到这一点？

Answer 1

您非常接近，微小的编辑将为您提供一个有效的解决方案。问题是你混合了符号和字符串。这将会起作用：

(defmacro ssm-list-prop-defun (field)
                   ;; note that concat operates on strings
  `(defun ,(intern (concat "ssm-list-" field))
     (one-list)
          ;; note that you need a symbol here, so quote the 
          ;; result of the call to intern
          ;; and, if you're always using symbols, 
          ;; might as well use assq
     (cdr (assq ',(intern field) (car (cdr one-list))))))

;; pass in a string
(ssm-list-prop-defun "name")

下面是使用符号的变体：

;; variant that works off a symbol
(defmacro ssm-list-prop-defun (field)
  `(defun ,(intern (concat "ssm-list-" (symbol-name field)))
     (one-list)
     (cdr (assq ',field (car (cdr one-list))))))

(ssm-list-prop-defun name)

Answer 2

我认为您应该阅读cl包中的defstruct：(info "(cl) Structures") (或http://www.gnu.org/software/emacs/manual/html_node/cl/Structures.html#Structures)