lexicaltest.clj

(def foo (fn foo [x]
           (if (zero? x)
             x
             (foo (dec x)))))
(dotimes [i 3]
  (println "lexical binding run" i)
  (time
   (dotimes [i 1000]
     (foo i))))

(def bar (fn [x]
           (if (zero? x)
             x
             (bar (dec x)))))

(dotimes [i 3]
  (println "var binding run" i)
  (time
   (dotimes [i 1000]
     (bar i))))