Merge pull request #3304 from kamilkloch/syntax-all

core/shared/src/main/scala/cats/effect/IO.scala

@@ -38,7 +38,7 @@ import cats.data.Ior
 import cats.effect.instances.spawn
 import cats.effect.kernel.CancelScope
 import cats.effect.kernel.GenTemporal.handleDuration
-import cats.effect.std.{Console, Env, UUIDGen}
+import cats.effect.std.{Backpressure, Console, Env, Supervisor, UUIDGen}
 import cats.effect.tracing.{Tracing, TracingEvent}
 import cats.syntax.all._
 
@@ -497,6 +497,15 @@ sealed abstract class IO[+A] private () extends IOPlatform[A] {
    */
   def map[B](f: A => B): IO[B] = IO.Map(this, f, Tracing.calculateTracingEvent(f))
 
+  /**
+   * Applies rate limiting to this `IO` based on provided backpressure semantics.
+   *
+   * @return
+   *   an Option which denotes if this `IO` was run or not according to backpressure semantics
+   */
+  def metered(backpressure: Backpressure[IO]): IO[Option[A]] =
+    backpressure.metered(this)
+
   def onCancel(fin: IO[Unit]): IO[A] =
     IO.OnCancel(this, fin)
 
@@ -610,6 +619,15 @@ sealed abstract class IO[+A] private () extends IOPlatform[A] {
     else
       flatMap(_ => replicateA_(n - 1))
 
+  /**
+   * Starts this `IO` on the supervisor.
+   *
+   * @return
+   *   a [[cats.effect.kernel.Fiber]] that represents a handle to the started fiber.
+   */
+  def supervise(supervisor: Supervisor[IO]): IO[Fiber[IO, Throwable, A @uncheckedVariance]] =
+    supervisor.supervise(this)
+
   /**
    * Logs the value of this `IO` _(even if it is an error or if it was cancelled)_ to the
    * standard output, using the implicit `cats.Show` instance.
@@ -735,6 +753,11 @@ sealed abstract class IO[+A] private () extends IOPlatform[A] {
   def timed: IO[(FiniteDuration, A)] =
     Clock[IO].timed(this)
 
+  /**
+   * Lifts this `IO` into a resource. The resource has a no-op release.
+   */
+  def toResource: Resource[IO, A] = Resource.eval(this)
+
   def product[B](that: IO[B]): IO[(A, B)] =
     flatMap(a => that.map(b => (a, b)))