Packages

final case class Eval[F[_], A](fa: F[A]) extends Resource[F, A] with Product with Serializable

Source
Resource.scala
Linear Supertypes
Product, Equals, Resource[F, A], Serializable, AnyRef, Any
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  1. Eval
  2. Product
  3. Equals
  4. Resource
  5. Serializable
  6. AnyRef
  7. Any
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Visibility
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Instance Constructors

  1. new Eval(fa: F[A])

Value Members

  1. final def !=(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  2. def !>[B](that: Resource[F, B])(implicit F: MonadCancel[F, Throwable]): Resource[F, B]
    Definition Classes
    Resource
  3. final def ##: Int
    Definition Classes
    AnyRef → Any
  4. final def ==(arg0: Any): Boolean
    Definition Classes
    AnyRef → Any
  5. def allocated[B >: A](implicit F: MonadCancel[F, Throwable]): F[(B, F[Unit])]

    Given a Resource, possibly built by composing multiple Resources monadically, returns the acquired resource, as well as an action that runs all the finalizers for releasing it.

    Given a Resource, possibly built by composing multiple Resources monadically, returns the acquired resource, as well as an action that runs all the finalizers for releasing it.

    If the outer F fails or is interrupted, allocated guarantees that the finalizers will be called. However, if the outer F succeeds, it's up to the user to ensure the returned F[Unit] is called once A needs to be released. If the returned F[Unit] is not called, the finalizers will not be run.

    For this reason, this is an advanced and potentially unsafe api which can cause a resource leak if not used correctly, please prefer use as the standard way of running a Resource program.

    Use cases include interacting with side-effectful apis that expect separate acquire and release actions (like the before and after methods of many test frameworks), or complex library code that needs to modify or move the finalizer for an existing resource.

    Definition Classes
    Resource
  6. def allocatedCase[B >: A](implicit F: MonadCancel[F, Throwable]): F[(B, (ExitCase) => F[Unit])]

    Given a Resource, possibly built by composing multiple Resources monadically, returns the acquired resource, as well as a cleanup function that takes an exit case and runs all the finalizers for releasing it.

    Given a Resource, possibly built by composing multiple Resources monadically, returns the acquired resource, as well as a cleanup function that takes an exit case and runs all the finalizers for releasing it.

    If the outer F fails or is interrupted, allocated guarantees that the finalizers will be called. However, if the outer F succeeds, it's up to the user to ensure the returned ExitCode => F[Unit] is called once A needs to be released. If the returned ExitCode => F[Unit] is not called, the finalizers will not be run.

    For this reason, this is an advanced and potentially unsafe api which can cause a resource leak if not used correctly, please prefer use as the standard way of running a Resource program.

    Use cases include interacting with side-effectful apis that expect separate acquire and release actions (like the before and after methods of many test frameworks), or complex library code that needs to modify or move the finalizer for an existing resource.

    Definition Classes
    Resource
  7. final def asInstanceOf[T0]: T0
    Definition Classes
    Any
  8. def attempt[E](implicit F: ApplicativeError[F, E]): Resource[F, Either[E, A]]
    Definition Classes
    Resource
  9. def both[B](that: Resource[F, B])(implicit F: Concurrent[F]): Resource[F, (A, B)]

    Allocates two resources concurrently, and combines their results in a tuple.

    Allocates two resources concurrently, and combines their results in a tuple.

    The finalizers for the two resources are also run concurrently with each other, but within _each_ of the two resources, nested finalizers are run in the usual reverse order of acquisition.

    The same Resource.ExitCase is propagated to every finalizer. If both resources acquired successfully, the Resource.ExitCase is determined by the outcome of use. Otherwise, it is determined by which resource failed or canceled first during acquisition.

    Note that Resource also comes with a cats.Parallel instance that offers more convenient access to the same functionality as both, for example via parMapN:

    import scala.concurrent.duration._
import cats.effect.{IO, Resource}
import cats.effect.std.Random
import cats.syntax.all._

def mkResource(name: String) = {
  val acquire = for {
    n <- Random.scalaUtilRandom[IO].flatMap(_.nextIntBounded(1000))
    _ <- IO.sleep(n.millis)
    _ <- IO.println(s"Acquiring $$name")
  } yield name

  def release(name: String) =
    IO.println(s"Releasing $$name")

  Resource.make(acquire)(release)
}

val r = (mkResource("one"), mkResource("two"))
  .parMapN((s1, s2) => s"I have $s1 and $s2")
  .use(IO.println(_))
    Definition Classes
    Resource
  10. def clone(): AnyRef
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.CloneNotSupportedException]) @native()
  11. def combine[B >: A](that: Resource[F, B])(implicit A: Semigroup[B]): Resource[F, B]
    Definition Classes
    Resource
  12. def combineK[B >: A](that: Resource[F, B])(implicit F: MonadCancel[F, Throwable], K: SemigroupK[F], G: Make[F]): Resource[F, B]
    Definition Classes
    Resource
  13. final def eq(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  14. def evalMap[B](f: (A) => F[B]): Resource[F, B]

    Applies an effectful transformation to the allocated resource.

    Applies an effectful transformation to the allocated resource. Like a flatMap on F[A] while maintaining the resource context

    Definition Classes
    Resource
  15. def evalOn(ec: ExecutionContext)(implicit F: Async[F]): Resource[F, A]
    Definition Classes
    Resource
  16. def evalTap[B](f: (A) => F[B]): Resource[F, A]

    Applies an effectful transformation to the allocated resource.

    Applies an effectful transformation to the allocated resource. Like a flatTap on F[A] while maintaining the resource context

    Definition Classes
    Resource
  17. val fa: F[A]
  18. def finalize(): Unit
    Attributes
    protected[lang]
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.Throwable])
  19. def flatMap[B](f: (A) => Resource[F, B]): Resource[F, B]

    Implementation for the flatMap operation, as described via the cats.Monad type class.

    Implementation for the flatMap operation, as described via the cats.Monad type class.

    Definition Classes
    Resource
  20. def forceR[B](that: Resource[F, B])(implicit F: MonadCancel[F, Throwable]): Resource[F, B]
    Definition Classes
    Resource
  21. final def getClass(): Class[_ <: AnyRef]
    Definition Classes
    AnyRef → Any
    Annotations
    @native()
  22. def guaranteeCase(fin: (Outcome[[β$2$]Resource[F, β$2$], Throwable, A]) => Resource[F, Unit])(implicit F: MonadCancel[F, Throwable]): Resource[F, A]
    Definition Classes
    Resource
  23. def handleErrorWith[B >: A, E](f: (E) => Resource[F, B])(implicit F: ApplicativeError[F, E]): Resource[F, B]
    Definition Classes
    Resource
  24. final def isInstanceOf[T0]: Boolean
    Definition Classes
    Any
  25. def map[B](f: (A) => B): Resource[F, B]

    Given a mapping function, transforms the resource provided by this Resource.

    Given a mapping function, transforms the resource provided by this Resource.

    This is the standard Functor.map.

    Definition Classes
    Resource
  26. def mapK[G[_]](f: ~>[F, G])(implicit F: MonadCancel[F, _], G: MonadCancel[G, _]): Resource[G, A]

    Given a natural transformation from F to G, transforms this Resource from effect F to effect G.

    Given a natural transformation from F to G, transforms this Resource from effect F to effect G. The F and G constraint can also be satisfied by requiring a MonadCancelThrow[F] and MonadCancelThrow[G].

    Definition Classes
    Resource
  27. final def ne(arg0: AnyRef): Boolean
    Definition Classes
    AnyRef
  28. final def notify(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  29. final def notifyAll(): Unit
    Definition Classes
    AnyRef
    Annotations
    @native()
  30. def onCancel(fin: Resource[F, Unit])(implicit F: MonadCancel[F, Throwable]): Resource[F, A]
    Definition Classes
    Resource
  31. def onFinalize(finalizer: F[Unit])(implicit F: Applicative[F]): Resource[F, A]

    Runs finalizer when this resource is closed.

    Runs finalizer when this resource is closed. Unlike the release action passed to Resource.make, this will run even if resource acquisition fails or is canceled.

    Definition Classes
    Resource
  32. def onFinalizeCase(f: (ExitCase) => F[Unit])(implicit F: Applicative[F]): Resource[F, A]

    Like onFinalize, but the action performed depends on the exit case.

    Like onFinalize, but the action performed depends on the exit case.

    Definition Classes
    Resource
  33. def preAllocate(precede: F[Unit]): Resource[F, A]

    Runs precede before this resource is allocated.

    Runs precede before this resource is allocated.

    Definition Classes
    Resource
  34. def productElementNames: Iterator[String]
    Definition Classes
    Product
  35. def race[B](that: Resource[F, B])(implicit F: Concurrent[F]): Resource[F, Either[A, B]]

    Races the evaluation of two resource allocations and returns the result of the winner, except in the case of cancelation.

    Races the evaluation of two resource allocations and returns the result of the winner, except in the case of cancelation.

    Definition Classes
    Resource
  36. def start(implicit F: Concurrent[F]): Resource[F, Fiber[[β$3$]Resource[F, β$3$], Throwable, A]]
    Definition Classes
    Resource
  37. def surround[B](gb: F[B])(implicit F: MonadCancel[F, Throwable]): F[B]

    Acquires the resource, runs gb and closes the resource once gb terminates, fails or gets interrupted

    Acquires the resource, runs gb and closes the resource once gb terminates, fails or gets interrupted

    Definition Classes
    Resource
  38. def surroundK(implicit F: MonadCancel[F, Throwable]): ~>[F, F]

    Creates a FunctionK that can run gb within a resource, which is then closed once gb terminates, fails or gets interrupted

    Creates a FunctionK that can run gb within a resource, which is then closed once gb terminates, fails or gets interrupted

    Definition Classes
    Resource
  39. final def synchronized[T0](arg0: => T0): T0
    Definition Classes
    AnyRef
  40. def use[B](f: (A) => F[B])(implicit F: MonadCancel[F, Throwable]): F[B]

    Allocates a resource and supplies it to the given function.

    Allocates a resource and supplies it to the given function. The resource is released as soon as the resulting F[B] is completed, whether normally or as a raised error.

    f

    the function to apply to the allocated resource

    returns

    the result of applying [F] to

    Definition Classes
    Resource
  41. def useEval[B](implicit ev: <:<[A, F[B]], F: MonadCancel[F, Throwable]): F[B]

    For a resource that allocates an action (type F[B]), allocate that action, run it and release it.

    For a resource that allocates an action (type F[B]), allocate that action, run it and release it.

    Definition Classes
    Resource
  42. def useForever(implicit F: Spawn[F]): F[Nothing]

    Allocates a resource with a non-terminating use action.

    Allocates a resource with a non-terminating use action. Useful to run programs that are expressed entirely in Resource.

    The finalisers run when the resulting program fails or gets interrupted.

    Definition Classes
    Resource
  43. def useKleisli[B >: A, C](usage: Kleisli[F, B, C])(implicit F: MonadCancel[F, Throwable]): F[C]

    Allocates the resource and uses it to run the given Kleisli.

    Allocates the resource and uses it to run the given Kleisli.

    Definition Classes
    Resource
  44. def useKleisliK[B >: A](implicit F: MonadCancel[F, Throwable]): ~>[[γ$0$]Kleisli[F, B, γ$0$], F]

    Creates a FunctionK that, when applied, will allocate the resource and use it to run the given Kleisli.

    Creates a FunctionK that, when applied, will allocate the resource and use it to run the given Kleisli.

    Definition Classes
    Resource
  45. def use_(implicit F: MonadCancel[F, Throwable]): F[Unit]

    Allocates a resource and closes it immediately.

    Allocates a resource and closes it immediately.

    Definition Classes
    Resource
  46. final def wait(): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  47. final def wait(arg0: Long, arg1: Int): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException])
  48. final def wait(arg0: Long): Unit
    Definition Classes
    AnyRef
    Annotations
    @throws(classOf[java.lang.InterruptedException]) @native()

Inherited from Product

Inherited from Equals

Inherited from Resource[F, A]

Inherited from Serializable

Inherited from AnyRef

Inherited from Any

Ungrouped