The "feed" macro inserts what follows in the blank. Very handy. Author: chouser

gistfile1.clj

(use 'clojure.walk)

(defmacro _>_ [& exprs]
  (reduce
    (fn [inner step]
      (clojure.walk/postwalk-replace {'___ inner} step))
    (reverse exprs)))

(defn cat [lst, val, cont] #(cont (conj lst val)))

(trampoline (_>_ (cat [] 3 ___) (fn [l] (cat l 9 ___)) (fn [l] (println l))))

;[3 9]

(_>_ (assoc {:a "aa" :b "bda" :f "foo"} :d ___) (assoc [1 2 nil 7] 2 ___) (- (* 56 9) 403)) 

;{:d [1 2 101 7], :a "aa", :b "bda", :f "foo"}