Function fixed

packages/effect/src/internal/schedule.ts:755–787

(intervalInput: Duration.DurationInput)

/** @internal */
export const fixed = (intervalInput: Duration.DurationInput): Schedule.Schedule<number> => {
  const interval = Duration.decode(intervalInput)
  const intervalMillis = Duration.toMillis(interval)
  return makeWithState<[Option.Option<[number, number]>, number], unknown, number>(
    [Option.none(), 0],
    (now, _, [option, n]) =>
      core.sync(() => {
        switch (option._tag) {
          case "None": {
            return [
              [Option.some([now, now + intervalMillis]), n + 1],
              n,
              ScheduleDecision.continueWith(Interval.after(now + intervalMillis))
            ]
          }
          case "Some": {
            const [startMillis, lastRun] = option.value
            const runningBehind = now > (lastRun + intervalMillis)
            const boundary = Equal.equals(interval, Duration.zero)
              ? interval
              : Duration.millis(intervalMillis - ((now - startMillis) % intervalMillis))
            const sleepTime = Equal.equals(boundary, Duration.zero) ? interval : boundary
            const nextRun = runningBehind ? now : now + Duration.toMillis(sleepTime)
            return [
              [Option.some([startMillis, nextRun]), n + 1],
              n,
              ScheduleDecision.continueWith(Interval.after(nextRun))
            ]
          }
        }
      })
  )
}

/** @internal */
export const fromDelay = (delay: Duration.DurationInput): Schedule.Schedule<Duration.Duration> => duration(delay)