如何在没有ExecutionContext.global和IOApp的情况下使用cat效果？

Question

我有一个简单的IO操作序列，暂停5秒。

  implicit val timer = IO.timer(ExecutionContext.global)

  def doSth(str: String): IO[Unit] = IO(println(str))
  def greeting(): IO[Unit] =
    doSth("Before timer.") *>
      Timer[IO].sleep(5 second) *>
      doSth("After timer")

  val a = greeting().unsafeRunAsyncAndForget()

如何在没有ExecutionContext.global，IOApp的情况下制作计时器或修复ExecutionContext.global中的线程数量？

Answer 1

尝试

implicit val timer = IO.timer(ExecutionContext.fromExecutor(Executors.newFixedThreadPool(10)))

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