ZManaged
Related Docs:
class ZManaged
| package zio
A finalizer used in a ReleaseMap.
A finalizer used in a ReleaseMap. The Exit value passed to it is the result of executing ZManaged#use or an arbitrary value passed into ReleaseMap#release.
A scope in which resources can be safely preallocated.
A scope in which resources can be safely preallocated. Passing a ZManaged
to the apply method will create (inside an effect) a managed resource which
is already acquired and cannot fail.
A ReleaseMap represents the finalizers associated with a scope.
A ReleaseMap represents the finalizers associated with a scope.
The design of ReleaseMap is inspired by ResourceT, written by Michael Snoyman @snoyberg.
(https://github.com/snoyberg/conduit/blob/master/resourcet/Control/Monad/Trans/Resource/Internal.hs)
A scope in which ZManaged values can be safely allocated.
A scope in which ZManaged values can be safely allocated. Passing a managed
resource to the apply method will return an effect that allocates the resource
and returns it with an early-release handle.
Submerges the error case of an Either into the ZManaged.
Submerges the error case of an Either into the ZManaged. The inverse
operation of ZManaged.either.
Create a managed that accesses the environment.
Create a managed that accesses the environment.
Create a managed that accesses the environment.
Creates new ZManaged from a ZIO value that uses a ReleaseMap and returns a resource and a finalizer.
Creates new ZManaged from a ZIO value that uses a ReleaseMap and returns a resource and a finalizer.
The correct usage of this constructor consists of: - Properly registering a finalizer in the ReleaseMap as part of the ZIO value; - Managing interruption safety - take care to use ZIO.uninterruptible or ZIO.uninterruptibleMask to verify that the finalizer is registered in the ReleaseMap after acquiring the value; - Returning the finalizer returned from ReleaseMap#add. This is important to prevent double-finalization.
Evaluate each effect in the structure from left to right, collecting the the successful values and discarding the empty cases.
Evaluate each effect in the structure from left to right, collecting the
the successful values and discarding the empty cases. For a parallel version, see collectPar.
Evaluate each effect in the structure from left to right, and collect the results.
Evaluate each effect in the structure from left to right, and collect the
results. For a parallel version, see collectAllPar.
Evaluate each effect in the structure in parallel, and collect the results.
Evaluate each effect in the structure in parallel, and collect the
results. For a sequential version, see collectAll.
Evaluate each effect in the structure in parallel, and collect the results.
Evaluate each effect in the structure in parallel, and collect the
results. For a sequential version, see collectAll.
Unlike CollectAllPar, this method will use at most n fibers.
Evaluate each effect in the structure in parallel, and discard the results.
Evaluate each effect in the structure in parallel, and discard the
results. For a sequential version, see collectAll_.
Unlike CollectAllPar_, this method will use at most n fibers.
Evaluate each effect in the structure in parallel, and discard the results.
Evaluate each effect in the structure in parallel, and discard the
results. For a sequential version, see collectAll_.
Evaluate each effect in the structure from left to right, and discard the results.
Evaluate each effect in the structure from left to right, and discard the
results. For a parallel version, see collectAllPar_.
Evaluate each effect in the structure in parallel, collecting the the successful values and discarding the empty cases.
Evaluate each effect in the structure in parallel, collecting the the successful values and discarding the empty cases.
Evaluate each effect in the structure in parallel, collecting the the successful values and discarding the empty cases.
Unlike collectPar, this method will use at most up to n fibers.
Similar to Either.cond, evaluate the predicate, return the given A as success if predicate returns true, and the given E as error otherwise
Returns an effect that dies with the specified Throwable.
Returns an effect that dies with the specified Throwable.
This method can be used for terminating a fiber because a defect has been
detected in the code.
Returns an effect that dies with a java.lang.RuntimeException having the specified text message.
Returns an effect that dies with a java.lang.RuntimeException having the specified text message. This method can be used for terminating a fiber because a defect has been detected in the code.
Returns an effect from a lazily evaluated zio.Exit value.
Lifts a synchronous side-effect into a ZManaged[R, Throwable, A],
translating any thrown exceptions into typed failed effects.
Lifts a by-name, pure value into a Managed.
Accesses the whole environment of the effect.
Returns an effect that models failure with the specified error.
Returns an effect that models failure with the specified error.
The moral equivalent of throw for pure code.
Returns an effect that succeeds with the Fiber.Id of the caller.
Creates an effect that only executes the provided finalizer as its release action.
Creates an effect that only executes the provided function as its release action.
Creates an effect that executes a finalizer stored in a Ref.
Creates an effect that executes a finalizer stored in a Ref.
The Ref is yielded as the result of the effect, allowing for
control flows that require mutating finalizers.
Returns an effectful function that extracts out the first element of a tuple.
Returns an effect that performs the outer effect first, followed by the inner effect, yielding the value of the inner effect.
Returns an effect that performs the outer effect first, followed by the inner effect, yielding the value of the inner effect.
This method can be used to "flatten" nested effects.
Returns an effect that performs the outer effect first, followed by the inner effect, yielding the value of the inner effect.
Returns an effect that performs the outer effect first, followed by the inner effect, yielding the value of the inner effect.
This method can be used to "flatten" nested effects.
Folds an Iterable[A] using an effectual function f, working sequentially from left to right.
Applies the function f if the argument is non-empty and
returns the results in a new Option[A2].
Applies the function f to each element of the Collection[A] and
returns the results in a new Collection[B].
Applies the function f to each element of the Collection[A] and
returns the results in a new Collection[B].
For a parallel version of this method, see foreachPar.
If you do not need the results, see foreach_ for a more efficient implementation.
Applies the function f to each element of the Collection[A] and returns
the result in a new Collection[B] using the specified execution strategy.
Applies the function f to each element of the Collection[A] in parallel,
and returns the results in a new Collection[B].
Applies the function f to each element of the Collection[A] in parallel,
and returns the results in a new Collection[B].
For a sequential version of this method, see foreach.
Applies the function f to each element of the Collection[A] in parallel,
and returns the results in a new Collection[B].
Applies the function f to each element of the Collection[A] in parallel,
and returns the results in a new Collection[B].
Unlike foreachPar, this method will use at most up to n fibers.
Applies the function f to each element of the Iterable[A] and runs
produced effects in parallel, discarding the results.
Applies the function f to each element of the Iterable[A] and runs
produced effects in parallel, discarding the results.
Unlike foreachPar_, this method will use at most up to n fibers.
Applies the function f to each element of the Iterable[A] and runs
produced effects in parallel, discarding the results.
Applies the function f to each element of the Iterable[A] and runs
produced effects in parallel, discarding the results.
For a sequential version of this method, see foreach_.
Applies the function f to each element of the Iterable[A] and runs
produced effects sequentially.
Applies the function f to each element of the Iterable[A] and runs
produced effects sequentially.
Equivalent to foreach(as)(f).unit, but without the cost of building
the list of results.
Creates a ZManaged from an AutoCloseable resource.
Creates a ZManaged from an AutoCloseable resource. The resource's close
method will be used as the release action.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with no release action.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with no release action. The effect will be performed interruptibly.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with no release action.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with no release action. The effect will be performed uninterruptibly. You usually want the ZManaged.fromEffect variant.
Lifts an Either into a ZManaged value.
Lifts a function R => A into a ZManaged[R, Nothing, A].
Lifts an effectful function whose effect requires no environment into an effect that requires the input to the function.
Returns an effect that models failure with the specified Cause.
Returns the identity effectful function, which performs no effects
Runs onTrue if the result of b is true and onFalse otherwise.
Returns an effect that is interrupted as if by the fiber calling this method.
Returns an effect that is interrupted as if by the specified fiber.
Iterates with the specified effectual function.
Iterates with the specified effectual function. The moral equivalent of:
var s = initial while (cont(s)) { s = body(s) } s
Loops with the specified effectual function, collecting the results into a list.
Loops with the specified effectual function, collecting the results into a list. The moral equivalent of:
var s = initial var as = List.empty[A] while (cont(s)) { as = body(s) :: as s = inc(s) } as.reverse
Loops with the specified effectual function purely for its effects.
Loops with the specified effectual function purely for its effects. The moral equivalent of:
var s = initial while (cont(s)) { body(s) s = inc(s) }
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with a release action.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with a release action.
The acquire and release actions will be performed uninterruptibly.
Lifts a synchronous effect into ZManaged[R, Throwable, A] with a release action.
Lifts a synchronous effect into ZManaged[R, Throwable, A] with a release action.
The acquire and release actions will be performed uninterruptibly.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with a release action that handles Exit.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with a release action that handles Exit.
The acquire and release actions will be performed uninterruptibly.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with a release action.
Lifts a ZIO[R, E, A] into ZManaged[R, E, A] with a release action. The acquire action will be performed interruptibly, while release will be performed uninterruptibly.
Creates a ZManaged from a Reservation produced by an effect.
Creates a ZManaged from a Reservation produced by an effect. Evaluating the effect that produces the reservation will be performed *uninterruptibly*, while the acquisition step of the reservation will be performed *interruptibly*. The release step will be performed uninterruptibly as usual.
This two-phase acquisition allows for resource acquisition flows that can be safely interrupted and released. For an example, see Semaphore#withPermitsManaged.
Sequentially zips the specified effects using the specified combiner function.
Sequentially zips the specified effects using the specified combiner function.
Sequentially zips the specified effects using the specified combiner function.
Returns an effect that executes the specified effects in parallel,
combining their results with the specified f function.
Returns an effect that executes the specified effects in parallel,
combining their results with the specified f function. If any effect
fails, then the other effects will be interrupted.
Returns an effect that executes the specified effects in parallel,
combining their results with the specified f function.
Returns an effect that executes the specified effects in parallel,
combining their results with the specified f function. If any effect
fails, then the other effects will be interrupted.
Returns an effect that executes the specified effects in parallel,
combining their results with the specified f function.
Returns an effect that executes the specified effects in parallel,
combining their results with the specified f function. If any effect
fails, then the other effects will be interrupted.
Merges an Iterable[ZManaged] to a single ZManaged, working sequentially.
Merges an Iterable[ZManaged] to a single ZManaged, working in parallel.
Merges an Iterable[ZManaged] to a single ZManaged, working in parallel.
Due to the parallel nature of this combinator, f must be both:
- commutative: f(a, b) == f(b, a)
- associative: f(a, f(b, c)) == f(f(a, b), c)
Merges an Iterable[ZManaged] to a single ZManaged, working in parallel.
Merges an Iterable[ZManaged] to a single ZManaged, working in parallel.
Due to the parallel nature of this combinator, f must be both:
- commutative: f(a, b) == f(b, a)
- associative: f(a, f(b, c)) == f(f(a, b), c)
Unlike mergeAllPar, this method will use at most up to n fibers.
Returns a ZManaged that never acquires a resource.
Creates a scope in which resources can be safely preallocated.
Reduces an Iterable[IO] to a single IO, working sequentially.
Reduces an Iterable[IO] to a single IO, working in parallel.
Reduces an Iterable[IO] to a single IO, working in parallel.
Reduces an Iterable[IO] to a single IO, working in parallel.
Unlike mergeAllPar, this method will use at most up to n fibers.
This is not implemented in terms of ZIO.foreach / ZManaged.zipWithPar as otherwise all reservation phases would always run, causing unnecessary work
Provides access to the entire map of resources allocated by this ZManaged.
Requires that the given ZManaged[E, Option[A]] contain a value.
Requires that the given ZManaged[E, Option[A]] contain a value. If there is no
value, then the specified error will be raised.
Lifts a pure Reservation[R, E, A] into ZManaged[R, E, A].
Lifts a pure Reservation[R, E, A] into ZManaged[R, E, A]. The acquisition step
is performed interruptibly.
Returns an ZManaged that accesses the runtime, which can be used to (unsafely) execute tasks.
Returns an ZManaged that accesses the runtime, which can be used to (unsafely) execute tasks. This is useful for integration with legacy code that must call back into ZIO code.
Creates a scope in which resources can be safely allocated into together with a release action.
Returns an effectful function that extracts out the second element of a tuple.
Accesses the specified service in the environment of the effect.
Accesses the specified services in the environment of the effect.
Accesses the specified services in the environment of the effect.
Accesses the specified services in the environment of the effect.
Returns an effect with the optional value.
Lifts a lazy, pure value into a Managed.
Returns a lazily constructed Managed.
Returns an effectful function that merely swaps the elements in a Tuple2.
Returns a ZManaged value that represents a managed resource that can be safely swapped within the scope of the ZManaged.
Returns a ZManaged value that represents a managed resource that can be safely swapped within the scope of the ZManaged. The function provided inside the ZManaged can be used to switch the resource currently in use.
When the resource is switched, the finalizer for the previous finalizer will be executed uninterruptibly. If the effect executing inside the ZManaged#use is interrupted, the finalizer for the resource currently in use is guaranteed to execute.
This constructor can be used to create an expressive control flow that uses several instances of a managed resource. For example:
def makeWriter: Task[FileWriter] trait FileWriter { def write(data: Int): Task[Unit] def close: UIO[Unit] } val elements = List(1, 2, 3, 4) val writingProgram = ZManaged.switchable[Any, Throwable, FileWriter].use { switchWriter => ZIO.foreach_(elements) { element => for { writer <- switchWriter(makeWriter.toManaged(_.close)) _ <- writer.write(element) } yield () } }
Returns the effect resulting from mapping the success of this effect to unit.
The moral equivalent of if (!p) exp
The moral equivalent of if (!p) exp when p has side-effects
The inverse operation to sandbox.
The inverse operation to sandbox. Submerges the full cause of failure.
Unwraps a ZManaged that is inside a ZIO.
The moral equivalent of if (p) exp
Runs an effect when the supplied PartialFunction matches for the given value, otherwise does nothing.
Runs an effect when the supplied PartialFunction matches for the given effectful value, otherwise does nothing.
The moral equivalent of if (p) exp when p has side-effects
Locally installs a supervisor and an effect that succeeds with all the children that have been forked in the returned effect.