iterators.nim

import os
import times

const
  speed = 1000

iterator deltat(): int {.closure.} =
  var
    t0: float = epochTime()
    t1: float
  while true:
    t1 = epochTime()
    yield ((t1 - t0) * 1_000).toInt()
    t0 = t1

iterator nextframe(): bool {.closure.} =
  let
    genDeltaT = deltat
  var
    accTime: int = 0
  while true:
    accTime += genDeltaT()

    if accTime >= speed:
      yield true
      accTime = 0
    else:
      yield false

var
  genNextFrame = nextframe

while true:
  if genNextFrame():
    echo "FINISH"
    quit()
  sleep(1)