Ref

A mutable atomic reference for the IO monad. This is the IO equivalent of a volatile var, augmented with atomic operations, which make it useful as a reasonably efficient (if low-level) concurrency primitive.

for {
  ref <- Ref(2)
  v   <- ref.update(_ + 3)
  _   <- putStrLn("Value = " + v) // Value = 5
} yield ()

Linear Supertypes

AnyVal, Any

Value Members

final def !=(arg0: Any): Boolean

Definition Classes
Any
final def ##(): Int

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

Definition Classes
Any
final def asInstanceOf[T0]: T0

Definition Classes
Any
final def compareAndSet(prev: A, next: A): IO[Nothing, Boolean]

Compares and sets the value of the Ref if and only if it is eq to the specified value.
Compares and sets the value of the Ref if and only if it is eq to the specified value. Returns whether or not the ref was modified.
final def get: IO[Nothing, A]

Reads the value from the Ref.
def getClass(): Class[_ <: AnyVal]

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

Definition Classes
Any
final def modify[B](f: (A) ⇒ (B, A)): IO[Nothing, B]

Atomically modifies the Ref with the specified function, which computes a return value for the modification.
Atomically modifies the Ref with the specified function, which computes a return value for the modification. This is a more powerful version of update.
final def set(a: A): IO[Nothing, Unit]

Writes a new value to the Ref, with a guarantee of immediate consistency (at some cost to performance).
final def setLater(a: A): IO[Nothing, Unit]

Writes a new value to the Ref without providing a guarantee of immediate consistency.
def toString(): String

Definition Classes
Any
final def trySet(a: A): IO[Nothing, Boolean]

Attempts to write a new value to the Ref, but aborts immediately under concurrent modification of the value by other fibers.
final def update(f: (A) ⇒ A): IO[Nothing, A]

Atomically modifies the Ref with the specified function.
Atomically modifies the Ref with the specified function. This is not implemented in terms of modify purely for performance reasons.

Related Docs: object Ref | package zio

final class Ref[A] extends AnyVal

Value Members

final def !=(arg0: Any): Boolean

final def ##(): Int

final def ==(arg0: Any): Boolean

final def asInstanceOf[T0]: T0

final def compareAndSet(prev: A, next: A): IO[Nothing, Boolean]

final def get: IO[Nothing, A]

def getClass(): Class[_ <: AnyVal]

final def isInstanceOf[T0]: Boolean

final def modify[B](f: (A) ⇒ (B, A)): IO[Nothing, B]

final def set(a: A): IO[Nothing, Unit]

final def setLater(a: A): IO[Nothing, Unit]

def toString(): String

final def trySet(a: A): IO[Nothing, Boolean]

final def update(f: (A) ⇒ A): IO[Nothing, A]

Inherited from AnyVal

Inherited from Any

Ungrouped