import cats.effect.{ExitCode, IO, IOApp}
import cats.implicits._
import fs2.Stream

object Main extends IOApp {
  override def run(args: List[String]): IO[ExitCode] = {
    val stream =
      Stream
        .iterate(0)(_ + 1)
        .covary[IO]
        .mapAsync(25) { n =>
          if (n > 100) IO.raiseError(new RuntimeException)
          else IO(println(n))
        }

    stream.compile.drain.as(ExitCode.Success)
  }
}