Clojure macro for delayed executino

after.clj

(defmacro after
  "Sleeps for t miliseconds then executes body. Immediately
   returns a future from which the result of executing body
   can (eventually) be obtained by `deref`"
  {:author "Matthew Gilliard"}
  
  [t & body]
  `(future
     (java.lang.Thread/sleep ~t)
     ~@body))

(macroexpand-1
 '(after 100 (println "banana")))

(do
  (let [result (after 1000
                 (println "fooo")
                 (+ 2 3 4))]

    (println "done")
    (println @result)))

; done
;  -wait a second
; fooo
; 9