Monkeying with Clojure’s defmethod Macro

defmethod-explicit.clj

(defmacro defmethod-explicit
  [multifn dispatch-val & fn-tail]
  (let [[kw n & body] fn-tail]
    (if (= :as kw)
      `(let [~n ~dispatch-val]
	 (defmethod ~multifn ~dispatch-val ~body))
      `(defmethod  ~multifn ~dispatch-val ~fn-tail))))

(defmulti expl-mm (juxt first second))

(defmethod-explicit expl-mm [1 2] :as dv [_] (str dv))
(defmethod-explicit expl-mm [3 4] [s] (reverse s))

(expl-mm [1 2])
(expl-mm [3 4])