clojure dynamic binding

gistfile1.clj

user=> (defn slow-double [n] (Thread/sleep 100) (* n 2))
#'user/slow-double
user=> (defn calls-slow-double [] (map slow-double [1 2 1 2 1 2]))
#'user/calls-slow-double
user=> (calls-slow-double )
(2 4 2 4 2 4)
user=> (time (dorun (calls-slow-double)))
"Elapsed time: 601.008572 msecs"
nil
user=> (defn demo-memoize []
(time
  (dorun
    (binding [slow-double (memoize slow-double)]
      (calls-slow-double)))))
#'user/demo-memoize
user=> (demo-memoize )
"Elapsed time: 200.975626 msecs"
nil