trait MonadError[F[_], E] extends ApplicativeError[F, E] with Monad[F] {

trait MonadCancel[F[_], E] extends MonadError[F, E] {

  // analogous to productR, except discarding short-circuiting (and optionally some effect contexts) except for cancelation
  def forceR[A, B](fa: F[A])(fb: F[B]): F[B]

  def uncancelable[A](body: Poll[F] => F[A]): F[A]

  // produces an effect which is already canceled (and doesn't introduce an async boundary)
  // this is effectively a way for a fiber to commit suicide and yield back to its parent
  // The fallback (unit) value is produced if the effect is sequenced into a block in which
  // cancelation is suppressed.
  def canceled: F[Unit]

  def onCancel[A](fa: F[A], fin: F[Unit]): F[A]

trait MonadError[F[_], E] extends ApplicativeError[F, E] with Monad[F] {

trait MonadCancel[F[_], E] extends MonadError[F, E] {

  // analogous to productR, except discarding short-circuiting (and optionally some effect contexts) except for cancelation
  def forceR[A, B](fa: F[A])(fb: F[B]): F[B]

  def uncancelable[A](body: Poll[F] => F[A]): F[A]

  // produces an effect which is already canceled (and doesn't introduce an async boundary)
  // this is effectively a way for a fiber to commit suicide and yield back to its parent
  // The fallback (unit) value is produced if the effect is sequenced into a block in which
  // cancelation is suppressed.
  def canceled: F[Unit]

  def onCancel[A](fa: F[A], fin: F[Unit]): F[A]

trait MonadError[F[_], E] extends ApplicativeError[F, E] with Monad[F] {

trait MonadCancel[F[_], E] extends MonadError[F, E] {

  // analogous to productR, except discarding short-circuiting (and optionally some effect contexts) except for cancelation
  def forceR[A, B](fa: F[A])(fb: F[B]): F[B]

  def uncancelable[A](body: Poll[F] => F[A]): F[A]

  // produces an effect which is already canceled (and doesn't introduce an async boundary)
  // this is effectively a way for a fiber to commit suicide and yield back to its parent
  // The fallback (unit) value is produced if the effect is sequenced into a block in which
  // cancelation is suppressed.
  def canceled: F[Unit]

  def onCancel[A](fa: F[A], fin: F[Unit]): F[A]