Pledge

Pledge is a value that can be completed later, much like a Scala Promise, but pure, to be used in describing laws that require the observation of side effects.

The internal implementation effectively wraps a Scala Promise, so it has the same contract:

it can only be "completed" once, being a write-once value
once written, the value is memoized for subsequent reads

Example:

for {
  pledge <- Pledge[IO, Int]
  fiber <- pledge.await[IO].start
  _ <- pledge.complete[IO](100)
  result <- fiber.join
} yield {
  result
}

Source: Pledge.scala

Linear Supertypes

AnyRef, Any

Instance Constructors

new Pledge()

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def ##(): Int

Definition Classes
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final def ==(arg0: Any): Boolean

Definition Classes
AnyRef → Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
def await[F[_]](implicit F: Async[F]): F[A]

Awaits for the pledge to be completed, then returns the final value.
def clone(): AnyRef

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( ... )
def complete[F[_]](a: A)(implicit F: Sync[F]): F[Unit]

Completes this pledge with the given value.
Completes this pledge with the given value.
It's a protocol violation to try and complete the pledge twice. The second time will end in error.
final def eq(arg0: AnyRef): Boolean

Definition Classes
AnyRef
def equals(arg0: Any): Boolean

Definition Classes
AnyRef → Any
def finalize(): Unit

Attributes
protected[java.lang]
Definition Classes
AnyRef
Annotations
@throws( classOf[java.lang.Throwable] )
final def getClass(): Class[_]

Definition Classes
AnyRef → Any
def hashCode(): Int

Definition Classes
AnyRef → Any
final def isInstanceOf[T0]: Boolean

Definition Classes
Any
final def ne(arg0: AnyRef): Boolean

Definition Classes
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final def notify(): Unit

Definition Classes
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final def notifyAll(): Unit

Definition Classes
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final def synchronized[T0](arg0: ⇒ T0): T0

Definition Classes
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def toString(): String

Definition Classes
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final def wait(): Unit

Definition Classes
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Annotations
@throws( ... )
final def wait(arg0: Long, arg1: Int): Unit

Definition Classes
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Annotations
@throws( ... )
final def wait(arg0: Long): Unit

Definition Classes
AnyRef
Annotations
@throws( ... )

Related Docs: object Pledge | package util

final class Pledge[A] extends AnyRef

Instance Constructors

new Pledge()

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

def await[F[_]](implicit F: Async[F]): F[A]

def clone(): AnyRef

def complete[F[_]](a: A)(implicit F: Sync[F]): F[Unit]

final def eq(arg0: AnyRef): Boolean

def equals(arg0: Any): Boolean

def finalize(): Unit

final def getClass(): Class[_]

def hashCode(): Int

final def isInstanceOf[T0]: Boolean

final def ne(arg0: AnyRef): Boolean

final def notify(): Unit

final def notifyAll(): Unit

final def synchronized[T0](arg0: ⇒ T0): T0

def toString(): String

final def wait(): Unit

final def wait(arg0: Long, arg1: Int): Unit

final def wait(arg0: Long): Unit

Inherited from AnyRef

Inherited from Any

Ungrouped