package std
- Alphabetic
- Public
- Protected
Type Members
- final case class Const[+O](out: O) extends Fn[Any, O] with Product with Serializable
A stage that always produces the same constant output, ignoring its input.
A stage that always produces the same constant output, ignoring its input.
Constwraps a fixed valueoutand returns it on every invocation, always succeeding (h8io.stages.Status.Success). Because it is a h8io.stages.base.Fn, it is stateless and can be reused freely.Example:
val always42: Stage[Any, Int, Nothing] = Const(42)
- O
the output type (covariant)
- out
the constant value to produce on every invocation
- final case class Countdown[T](i: Long, n: Long) extends Endo[T, Nothing] with Endo[T, Nothing] with Product with Serializable
An endomorphic stage that passes its input through for exactly
ninvocations and then signals pipeline completion.An endomorphic stage that passes its input through for exactly
ninvocations and then signals pipeline completion.On each of the first
n − 1calls the stage yieldsh8io.stages.Status.Successand decrements its counter. On then-th call it yieldsh8io.stages.Status.Completeand resets ton. After anyh8io.stages.Status.Completethe stage also resets ton, ready for reuse.Countdownis fully immutable: each state transition creates a new instance rather than mutating the current one.Preconditions (checked at construction via
assume):n > 01 ≤ i ≤ n
- T
the value type passed through unchanged
- i
the remaining number of successful yields before completion (
1 ≤ i ≤ n)- n
the total period length (must be positive)
- sealed case class DeadEnd(_dispose: () => Unit) extends StaticStage[Any, Nothing, Nothing] with Product with Serializable
A terminal stage that never produces an output value.
A terminal stage that never produces an output value.
Every invocation of
applyreturns a pre-builth8io.stages.Yield.Nonewithh8io.stages.Status.Complete, immediately signaling that the pipeline is finished. Theh8io.stages.Yieldinstance is cached as avalto avoid allocation on each call.DeadEndis the natural "end-of-stream" marker and is also returned by Countdown.apply whenn ≤ 0and by h8io.stages.operators.LocalSoftDeadline when the duration is non-positive.An optional
_disposehook can be supplied at construction to release resources when the stage is disposed; the companion object DeadEnd uses a no-op hook.- _dispose
a thunk invoked by
h8io.stages.Evolution.dispose; defaults to a no-op in the companion object
- final class GlobalSoftDeadline[T] extends Endo[T, Nothing] with Endo[T, Nothing]
An endomorphic stage that passes values through as long as a wall-clock deadline has not elapsed.
An endomorphic stage that passes values through as long as a wall-clock deadline has not elapsed.
The deadline is measured from the moment this instance is created: the timestamp
tsis captured once at construction usingnow(). On each invocation, if the elapsed time (now() - ts) is less thanduration(in nanoseconds), the stage yieldsh8io.stages.Status.Success; otherwise it yieldsh8io.stages.Status.Complete.The deadline is global in the sense that it is fixed at construction and never resets, unlike h8io.stages.operators.LocalSoftDeadline which resets after each successful evolution transition.
- T
the value type passed through unchanged
Value Members
- object Coalesce extends Fn[Either[Any, Any], Any]
A stage that collapses an
Eitherby returning whichever side contains the value.A stage that collapses an
Eitherby returning whichever side contains the value.Coalescetakes anEither[T, T]and returns the contained value, regardless of whether it isLeftorRight. It always succeeds (h8io.stages.Status.Success) and never changes state, because it is a h8io.stages.base.Fn.Example:
val stage: Fn[Either[String, String], String] = Coalesce[String]
- object Complete extends Endo[Any, Nothing] with Endo[Any, Nothing]
A stage that immediately signals pipeline completion without dropping the input value.
A stage that immediately signals pipeline completion without dropping the input value.
Completealways yieldsh8io.stages.Status.Completewhile still passing the input through as the output. It is useful as the terminal element in a pipeline to stop further processing after a condition is met (see h8io.stages.operators.CompleteIfSome).The singleton operates on
Anyand can be safely cast to anyFruitful.Endo[T]viaapply[T]. - object Countdown extends Serializable
Factory for Countdown stages.
- object DeadEnd extends DeadEnd
Default no-op DeadEnd instance.
Default no-op DeadEnd instance.
Use
DeadEnddirectly as a stage or callDeadEnd(_dispose)to create a variant with a custom disposal hook. - object GlobalSoftDeadline
Factory for GlobalSoftDeadline stages.
- object Identity extends Endo[Any]
A stage that passes its input through unchanged.
A stage that passes its input through unchanged.
Identityis a singleton h8io.stages.base.Fn that acts as the identity function: given any value, it returns the same value. It always succeeds (h8io.stages.Status.Success) and never changes state.The singleton operates on
Anyand can be safely cast to any specificFn.Endo[T]via theapply[T]method, avoiding allocation on every use.Example:
val stage: Fn.Endo[String] = Identity[String]