4Clojure problem #58 Black box testing: Find type of set, map, vector, list without using built-in typing functions etc.

tipe58.clj

(defn tipe [s]
  (let [sym1  (gensym) sym2 (gensym) 
		sym3  (gensym) s12  (conj s {sym1 sym2}) 
        s1221 (conj (conj s {sym2 sym1}) s12)]
  (if (get s12 sym1) :map
      (if (get s12 {sym1 sym2}) :set      
          (if (= (first s1221) s12) :list :vector)))))

(= :map (tipe {:a 1, :b 2}))
(= :list (tipe (range (rand-int 20))))
(= :vector (tipe [1 2 3 4 5 6]))
(= :set (tipe #{10 (rand-int 5)}))
(= [:map :set :vector :list] (map tipe [{} #{} [] ()]))