如何在通用Lisp中编写宏定义宏 [英] How do I write a macro-defining macro in common lisp

问题描述

我的代码库中大约有两个宏(和攀爬宏)，如下所示:

I have about two macros (and climbing) in my codebase that look like this:

(defmacro def-stat-method (method-name stat)
  `(progn
     (defmethod ,method-name ((monster monster))
       (getf (stats monster) ,stat))
     (defmethod (setf ,method-name) (value (monster monster))
       (setf (getf (stats monster) ,stat) value))))

和这个:

(defmacro def-energy-method (method-name stat)
  `(progn
     (defmethod ,method-name ((monster monster))
       (getf (energies monster) ,stat))
     (defmethod (setf ,method-name) (value (monster monster))
       (setf (getf (energies monster) ,stat) value))))

每个宏具有以下调用语法:(def-stat-method ranged-weapon :ranged-weapon)

Each of the macros has the following calling syntax: (def-stat-method ranged-weapon :ranged-weapon)

我想将宏(def-foo-method macro-name method)扩展为适当的宏，以便(def-foo-method def-stat-method stats)扩展为上述第一个示例.我是个新手，不知道怎么做.感谢所有帮助.

I would like a macro (def-foo-method macro-name method) that expands into the appropriate macros so that (def-foo-method def-stat-method stats) expands into the first example above. I am a lisp newbie and don't really know how to do this. All help appreciated.

推荐答案

只需编写一个扩展为另一个defmacro的宏，如下所示:

Just write a macro that expands into another defmacro, like this:

(defmacro def-foo-method (macro-name method)
  `(defmacro ,macro-name (method-name stat)
     (let ((method ',method))
       `(progn
          (defmethod ,method-name ((monster monster))
            (getf (,method monster) ,stat))
          (defmethod (setf ,method-name) (value (monster monster))
            (setf (getf (,method monster) ,stat) value))))))

我认为没有let可能会有一种方法，但是嵌套的反引号令人困惑:)

I think there might be a way to do this without the let, but nested backticks are confusing :)

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