foldl vs foldr in erlang.

-module(fold).
-author('[email protected]').

-export([test/1]).

test(Max) ->
  lists:map(
    fun (F) ->
      benchmark(fun () ->
        F(fun (N, Acc) -> N + Acc end, 0, lists:seq(1, Max))
      end)
    end,
    [fun lists:foldl/3, fun lists:foldr/3]
  ).

benchmark(F) ->
  lists:foreach(fun statistics/1, [runtime, wall_clock]),
  Result = F(),
  Times = lists:map(
    fun (Type) -> {_, T} = statistics(Type), T end,
    [runtime, wall_clock]
  ),
  {Result, Times}.