Carp/core/Bench.carp

(defmodule Bench
  (system-include "bench.h")

  (register get-time-elapsed (Fn [] Double))

  (defn get-unit [n]
    (cond
      (> n 1000.0) (String.append (Double.str n) "µs")
      (> n 1000000.0) (String.append (Double.str (/ n 1000.0)) "ms")
      (> n 1000000000.0) (String.append (Double.str (/ n 1000000.0)) "s")
      (String.append (Double.str (/ n 1000000000.0)) "s")))

  (defn print [title n]
    (let [unit (get-unit n)]
      (do
        (IO.println title)
        (IO.println &unit))))

(defmacro bench [n form]
  (list 'let ['before (Bench.get-time-elapsed)
              'times []]
    (list 'do
      (list 'for ['i 0 n]
        (list 'let ['before-once (Bench.get-time-elapsed)]
          (list 'do
            form
            (list 'set! &times (Array.push-back (Array.copy &times) (Double.- (get-time-elapsed) before-once))))))
      (list 'let ['total (Double.- (Bench.get-time-elapsed) before)
                  'per (list 'Double./ 'total (list 'Double.from-int n))]
        (do
          (Bench.print "Total time elapsed: " total)
          (Bench.print "Time elapsed per run (average): " per)
          (Bench.print "Best case: " (Statistics.min &times))
          (Bench.print "Worst case: " (Statistics.max &times))
          (Bench.print "Standard deviation: " (Statistics.stdev &times)))))))