丧心病狂的使用宏的方法

reverse-it.clj

(require '(clojure [string :as string]
                   [walk :as walk]))

;; page 236 on <Clojure Programming>
(defmacro reverse-it [form]
  (walk/postwalk #(if (symbol? %)
                    (symbol (string/reverse (name %)))
                    %)
                 form))

(reverse-it
  (qesod [gra (egnar 5)]
    (nltnirp (cni gra))))
; 1
; 2
; 3
; 4
; 5
;= nil

(macroexpand-1 '(reverse-it
                 (qesod [gra (egnar 5)]
                        (nltnirp (cni gra)))))

(comment

  ;; 宏展开之后的实际形式
  (doseq [arg (range 5)]
    (println (inc arg)))

)