集结协议的Clojure宏

Question

作为后续行动，我previous question，我想写的是建立一个宏defprotocol：

(build-protocol AProtocol 
    [(a-method [this]) (b-method [this that])] 
    (map (fn [name] `(~(symbol (str name "-method")) [~'this ~'that ~'the-other])) 
    ["foo" "bar" "baz"]) 
    (map (fn [name] `(~(symbol (str name "-method")) [~'_])) 
    ["hello" "goodbye"])) 

应扩大到

(defprotocol AProtocol 
    (a-method [this]) 
    (b-method [this that]) 
    (foo-method [this that the-other]) 
    (bar-method [this that the-other]) 
    (baz-method [this that the-other]) 
    (hello-fn [_]) 
    (goodbye-fn [_])) 

我尝试：

(defmacro build-protocol [name simple & complex] 
    `(defprotocol ~name ~@simple 
    ~@(loop [complex complex ret []] 
     (if (seq complex) 
      (recur (rest complex) (into ret (eval (first complex)))) 
      ret)))) 

and expansion (macroexpand-1 '(...))：

(clojure.core/defprotocol AProtocol 
    (a-method [this]) 
    (b-method [this that]) 
    (foo-method [this that the-other]) 
    (bar-method [this that the-other]) 
    (baz-method [this that the-other]) 
    (hello-method [_]) 
    (goodbye-method [_])) 

我对eval并不满意。此外，map表达式很丑陋。有没有更好的办法？欢迎任何和所有评论。

一旦我得到这个工作，我会去做一个类似的宏，为(build-reify ...)。我正在编写一个相当大的Swing应用程序，它有几个组件（JButton s，JCheckBox es等），它们具有几乎相同的方法签名和操作。

Answer 1

我认为你是在颠倒。首先指定“-method”的东西，包装在某种容器中，这样build-protocol就知道是什么东西，并让它在宏内执行映射。例如：

(build-protocol AProtocol 
    {[this that whatever] [foo bar baz], 
    [_] [hello goodbye]} 
    ; a-method and b-method... 
)