macroexpand.clj

(defmacro time2 [expr times]
  `(time (dotimes [_# ~times] ~@expr)))

; -------------------------------------

(time2 (+ 1 2) 100)

; expands to ->

(let*
    [start__3913__auto__
  (. java.lang.System (nanoTime))
  ret__3914__auto__
  (let*
      [n__3820__auto__ (int 100)]
      (loop*
       [___20964__auto__ (int 0)]
       (if (< ___20964__auto__ n__3820__auto__)
           (do + 1 2 (recur (unchecked-inc ___20964__auto__))))))]
  (prn
   (str
    "Elapsed time: "
    (/
     (double (- (. java.lang.System (nanoTime)) start__3913__auto__))
     1000000.0)
    " msecs"))
  ret__3914__auto__)

; which is what actually gets compiled

; COMPARE

(defmacro time2 [expr times]
  (time `(dotimes [_# ~times] ~@expr)))

; -------------------------------------

(time2 (+ 1 2) 100)

; expands to ->

(let*
    [n__3820__auto__ (int 100)]
    (loop*
     [___21242__auto__ (int 0)]
     (if (< ___21242__auto__ n__3820__auto__)
         (do + 1 2 (recur (unchecked-inc ___21242__auto__))))))

; note that the lack of any measurement of time in the expanded code