zio/zio/Fiber

Fiber

sealed abstract class Fiber[+E, +A]

A fiber is a lightweight thread of execution that never consumes more than a whole thread (but may consume much less, depending on contention and asynchronicity). Fibers are spawned by forking ZIO effects, which run concurrently with the parent effect.

Fibers can be joined, yielding their result to other fibers, or interrupted, which terminates the fiber, safely releasing all resources.

def parallel[A, B](io1: Task[A], io2: Task[B]): Task[(A, B)] =
 for {
   fiber1 <- io1.fork
   fiber2 <- io2.fork
   a      <- fiber1.join
   b      <- fiber2.join
 } yield (a, b)
Companion:
object
class Object
trait Matchable
class Any
class Runtime[E, A]
class Synthetic[E, A]
Fiber[E, A]

Value members

Abstract methods

def await: UIO[Exit[E, A]]

Awaits the fiber, which suspends the awaiting fiber until the result of the fiber has been determined.

Awaits the fiber, which suspends the awaiting fiber until the result of the fiber has been determined.

Returns:

UIO[Exit[E, A]]

def getRef[A](ref: FiberRef[A]): UIO[A]

Gets the value of the fiber ref for this fiber, or the initial value of the fiber ref, if the fiber is not storing the ref.

Gets the value of the fiber ref for this fiber, or the initial value of the fiber ref, if the fiber is not storing the ref.

def inheritRefs: UIO[Unit]

Inherits values from all FiberRef instances into current fiber. This will resume immediately.

Inherits values from all FiberRef instances into current fiber. This will resume immediately.

Returns:

UIO[Unit]

def interruptAs(fiberId: Id): UIO[Exit[E, A]]

Interrupts the fiber as if interrupted from the specified fiber. If the fiber has already exited, the returned effect will resume immediately. Otherwise, the effect will resume when the fiber exits.

Interrupts the fiber as if interrupted from the specified fiber. If the fiber has already exited, the returned effect will resume immediately. Otherwise, the effect will resume when the fiber exits.

Returns:

UIO[Exit, E, A]]

def poll: UIO[Option[Exit[E, A]]]

Tentatively observes the fiber, but returns immediately if it is not already done.

Tentatively observes the fiber, but returns immediately if it is not already done.

Returns:

UIO[Option[Exit, E, A]]]

Concrete methods

final def *>[E1 >: E, B](that: Fiber[E1, B]): Synthetic[E1, B]

Same as zip but discards the output of the left hand side.

Same as zip but discards the output of the left hand side.

Type parameters:
B

type of the fiber

E1

error type

Value parameters:
that

fiber to be zipped

Returns:

Fiber[E1, B] combined fiber

final def <*[E1 >: E, B](that: Fiber[E1, B]): Synthetic[E1, A]

Same as zip but discards the output of the right hand side.

Same as zip but discards the output of the right hand side.

Type parameters:
B

type of the fiber

E1

error type

Value parameters:
that

fiber to be zipped

Returns:

Fiber[E1, A] combined fiber

final def <*>[E1 >: E, B](that: => Fiber[E1, B]): Synthetic[E1, (A, B)]

Zips this fiber and the specified fiber together, producing a tuple of their output.

Zips this fiber and the specified fiber together, producing a tuple of their output.

Type parameters:
B

type of that fiber

E1

error type

Value parameters:
that

fiber to be zipped

Returns:

Fiber[E1, (A, B)] combined fiber

final def <+>[E1 >: E, B](that: => Fiber[E1, B])(implicit ev: CanFail[E]): Synthetic[E1, Either[A, B]]

A symbolic alias for orElseEither.

A symbolic alias for orElseEither.

def <>[E1, A1 >: A](that: => Fiber[E1, A1])(implicit ev: CanFail[E]): Synthetic[E1, A1]

A symbolic alias for orElse.

A symbolic alias for orElse.

final def as[B](b: => B): Synthetic[E, B]

Maps the output of this fiber to the specified constant.

Maps the output of this fiber to the specified constant.

Type parameters:
B

type of the fiber

Value parameters:
b

constant

Returns:

Fiber[E, B] fiber mapped to constant

final def fold[Z](runtime: Runtime[E, A] => Z, synthetic: Synthetic[E, A] => Z): Z

Folds over the runtime or synthetic fiber.

Folds over the runtime or synthetic fiber.

final def interrupt: UIO[Exit[E, A]]

Interrupts the fiber from whichever fiber is calling this method. If the fiber has already exited, the returned effect will resume immediately. Otherwise, the effect will resume when the fiber exits.

Interrupts the fiber from whichever fiber is calling this method. If the fiber has already exited, the returned effect will resume immediately. Otherwise, the effect will resume when the fiber exits.

Returns:

UIO[Exit, E, A]]

final def interruptFork: UIO[Unit]

Interrupts the fiber from whichever fiber is calling this method. The interruption will happen in a separate daemon fiber, and the returned effect will always resume immediately without waiting.

Interrupts the fiber from whichever fiber is calling this method. The interruption will happen in a separate daemon fiber, and the returned effect will always resume immediately without waiting.

Returns:

UIO[Unit]

final def join: IO[E, A]

Joins the fiber, which suspends the joining fiber until the result of the fiber has been determined. Attempting to join a fiber that has erred will result in a catchable error. Joining an interrupted fiber will result in an "inner interruption" of this fiber, unlike interruption triggered by another fiber, "inner interruption" can be caught and recovered.

Joins the fiber, which suspends the joining fiber until the result of the fiber has been determined. Attempting to join a fiber that has erred will result in a catchable error. Joining an interrupted fiber will result in an "inner interruption" of this fiber, unlike interruption triggered by another fiber, "inner interruption" can be caught and recovered.

Returns:

IO[E, A]

final def map[B](f: A => B): Synthetic[E, B]

Maps over the value the Fiber computes.

Maps over the value the Fiber computes.

Type parameters:
B

result type of f

Value parameters:
f

mapping function

Returns:

Fiber[E, B] mapped fiber

final def mapFiber[E1 >: E, B](f: A => Fiber[E1, B]): UIO[Fiber[E1, B]]

Passes the success of this fiber to the specified callback, and continues with the fiber that it returns.

Passes the success of this fiber to the specified callback, and continues with the fiber that it returns.

Type parameters:
B

The success value.

Value parameters:
f

The callback.

Returns:

Fiber[E, B] The continued fiber.

final def mapM[E1 >: E, B](f: A => IO[E1, B]): Synthetic[E1, B]

Effectually maps over the value the fiber computes.

Effectually maps over the value the fiber computes.

def orElse[E1, A1 >: A](that: => Fiber[E1, A1])(implicit ev: CanFail[E]): Synthetic[E1, A1]

Returns a fiber that prefers this fiber, but falls back to the that one when this one fails. Interrupting the returned fiber will interrupt both fibers, sequentially, from left to right.

Returns a fiber that prefers this fiber, but falls back to the that one when this one fails. Interrupting the returned fiber will interrupt both fibers, sequentially, from left to right.

Type parameters:
A1

type of the other fiber

E1

error type

Value parameters:
that

fiber to fall back to

Returns:

Fiber[E1, A1]

final def orElseEither[E1, B](that: => Fiber[E1, B]): Synthetic[E1, Either[A, B]]

Returns a fiber that prefers this fiber, but falls back to the that one when this one fails. Interrupting the returned fiber will interrupt both fibers, sequentially, from left to right.

Returns a fiber that prefers this fiber, but falls back to the that one when this one fails. Interrupting the returned fiber will interrupt both fibers, sequentially, from left to right.

Type parameters:
B

type of the other fiber

E1

error type

Value parameters:
that

fiber to fall back to

Returns:

Fiber[E1, B]

final def toFuture(implicit ev: E <:< Throwable): UIO[CancelableFuture[A]]

Converts this fiber into a scala.concurrent.Future.

Converts this fiber into a scala.concurrent.Future.

Value parameters:
ev

implicit witness that E is a subtype of Throwable

Returns:

UIO[Future[A]]

final def toFutureWith(f: E => Throwable): UIO[CancelableFuture[A]]

Converts this fiber into a scala.concurrent.Future, translating any errors to java.lang.Throwable with the specified conversion function, using Cause.squashTraceWith

Converts this fiber into a scala.concurrent.Future, translating any errors to java.lang.Throwable with the specified conversion function, using Cause.squashTraceWith

Value parameters:
f

function to the error into a Throwable

Returns:

UIO[Future[A]]

final def toManaged: ZManaged[Any, Nothing, Fiber[E, A]]

Converts this fiber into a zio.ZManaged. Fiber is interrupted on release.

Converts this fiber into a zio.ZManaged. Fiber is interrupted on release.

Returns:

ZManaged[Any, Nothing, Fiber[E, A]]

final def unit: Synthetic[E, Unit]

Maps the output of this fiber to ().

Maps the output of this fiber to ().

Returns:

Fiber[E, Unit] fiber mapped to ()

final def zip[E1 >: E, B](that: => Fiber[E1, B]): Synthetic[E1, (A, B)]

Named alias for <*>.

Named alias for <*>.

Type parameters:
B

type of that fiber

E1

error type

Value parameters:
that

fiber to be zipped

Returns:

Fiber[E1, (A, B)] combined fiber

final def zipLeft[E1 >: E, B](that: Fiber[E1, B]): Synthetic[E1, A]

Named alias for <*.

Named alias for <*.

Type parameters:
B

type of the fiber

E1

error type

Value parameters:
that

fiber to be zipped

Returns:

Fiber[E1, A] combined fiber

final def zipRight[E1 >: E, B](that: Fiber[E1, B]): Synthetic[E1, B]

Named alias for *>.

Named alias for *>.

Type parameters:
B

type of the fiber

E1

error type

Value parameters:
that

fiber to be zipped

Returns:

Fiber[E1, B] combined fiber

final def zipWith[E1 >: E, B, C](that: => Fiber[E1, B])(f: (A, B) => C): Synthetic[E1, C]

Zips this fiber with the specified fiber, combining their results using the specified combiner function. Both joins and interruptions are performed in sequential order from left to right.

Zips this fiber with the specified fiber, combining their results using the specified combiner function. Both joins and interruptions are performed in sequential order from left to right.

Type parameters:
B

type of that fiber

C

type of the resulting fiber

E1

error type

Value parameters:
f

function to combine the results of both fibers

that

fiber to be zipped

Returns:

Fiber[E1, C] combined fiber