fac.pony

use "collections"
use "time"

primitive Factorial
  """ Factorial
  """
  fun fac(n:U64): U64 =>
    var f : U64 = 1
    var i : U64 = 1
    if n == 0 then
      0
    else
      repeat 
        f = f * i
        i = i + 1
      until i <= n end
      f
    end

actor Blackhole
  """ This is simply an actor that receives the factorial result
  """
  be receive(n: U64) =>
    None

actor FactorialServer
  """ This approximates the Erlang factorial_server
  """
  let bh : Blackhole = Blackhole

  be apply(f : U64) =>
    bh.receive(Factorial.fac(f))

actor Main
  let n : U64 = 10000000
  let fac : FactorialServer = FactorialServer
  new create(env : Env) =>
    let s : U64 = Time.nanos()
    for i in Range[U64](0,n) do
      fac(10)
    end
    let d = Time.nanos() - s
    env.out.print("Elapsed: " + d.string())