Value Members

1.  final def !=(arg0: Any): Boolean

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2.  final def ##(): Int

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3.  final def ==(arg0: Any): Boolean

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4.  def apply[F[_]](implicit F: Sync[F]): ApplyBuilders[F]

   Builds a Ref value for data types that are Sync

   Builds a Ref value for data types that are Sync

   This builder uses the Partially-Applied Type technique.

   Ref[IO].of(10) <-> Ref.of[IO, Int](10)

   See also

   of

5.  final def asInstanceOf[T0]: T0

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6.  def clone(): AnyRef

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   protected[java.lang]

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7.  final def eq(arg0: AnyRef): Boolean

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8.  def equals(arg0: Any): Boolean

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9.  def finalize(): Unit

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   protected[java.lang]

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   @throws( classOf[java.lang.Throwable] )

10.  final def getClass(): Class[_]

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    @native()

11.  def hashCode(): Int

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    @native()

12.  def in[F[_], G[_], A](a: A)(implicit F: Sync[F], G: Sync[G]): F[Ref[G, A]]

    Builds a Ref value for data types that are Sync Like of but initializes state using another effect constructor

13.  final def isInstanceOf[T0]: Boolean

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14.  final def ne(arg0: AnyRef): Boolean

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15.  final def notify(): Unit

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    @native()

16.  final def notifyAll(): Unit

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    @native()

17.  def of[F[_], A](a: A)(implicit F: Sync[F]): F[Ref[F, A]]

    Creates an asynchronous, concurrent mutable reference initialized to the supplied value.

    Creates an asynchronous, concurrent mutable reference initialized to the supplied value.

    import cats.effect.IO
    import cats.effect.concurrent.Ref
    
    for {
      intRef <- Ref.of[IO, Int](10)
      ten <- intRef.get
    } yield ten

18.  final def synchronized[T0](arg0: ⇒ T0): T0

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19.  def toString(): String

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20.  def unsafe[F[_], A](a: A)(implicit F: Sync[F]): Ref[F, A]

    Like apply but returns the newly allocated ref directly instead of wrapping it in F.delay.

    Like apply but returns the newly allocated ref directly instead of wrapping it in F.delay. This method is considered unsafe because it is not referentially transparent -- it allocates mutable state.

    This method uses the Partially Applied Type Params technique, so only effect type needs to be specified explicitly.

    Some care must be taken to preserve referential transparency:

    import cats.effect.IO
    import cats.effect.concurrent.Ref
    
    class Counter private () {
      private val count = Ref.unsafe[IO](0)
    
      def increment: IO[Unit] = count.modify(_ + 1)
      def total: IO[Int] = count.get
    }
    
    object Counter {
      def apply(): IO[Counter] = IO(new Counter)
    }

    Such usage is safe, as long as the class constructor is not accessible and the public one suspends creation in IO

    The recommended alternative is accepting a Ref[F, A] as a parameter:

    class Counter (count: Ref[IO, Int]) {
      // same body
    }
    
    object Counter {
      def apply(): IO[Counter] = Ref[IO](0).map(new Counter(_))
    }

21.  final def wait(): Unit

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

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    @throws( ... )

23.  final def wait(arg0: Long): Unit

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    @native() @throws( ... )