集結協議的Clojure宏

Question

作爲後續行動，我previous question，我想寫的是建立一個宏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"])) 

應擴大到

(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 [_])) 

我嘗試：

(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 [_])) 

我對eval並不滿意。此外，map表達式很醜陋。有沒有更好的辦法？歡迎任何和所有評論。

一旦我得到這個工作，我會去做一個類似的宏，爲(build-reify ...)。我正在編寫一個相當大的Swing應用程序，它有幾個組件（JButton s，JCheckBox es等），它們具有幾乎相同的方法簽名和操作。

Answer 1

我認爲你是在顛倒。首先指定「-method」的東西，包裝在某種容器中，這樣build-protocol就知道是什麼東西，並讓它在宏內執行映射。例如：

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