Times function running time (OCaml)

simpletimer.ml

(* Compile with unix.cma(x). *)

type timetrial = {
  time : float;
  result : string;
  }

let time_one f x =
  let start = Unix.gettimeofday () in
  let result = f x in
  let stop = Unix.gettimeofday () in
  let delta = stop -. start in
  { time = delta; result = result }

let rec collect acc repeats results f x =
  let result = f x in
  match (acc < repeats) with
  | false -> results
  | true -> collect (acc + 1) repeats (results @ [result]) f x

let repeat n f x =
  collect 0 n [] f x

let main =
  let trials = repeat 5 Unix.sleepf 0.25

let () =
  main;
  print_endline "Done."