CompleteIfSome

CompleteIfSome is a polymorphic singleton Decoration that stops the pipeline as soon as the decorated stage produces a value. It works by appending Complete via ~>: when the stage yields Yield.Some, Complete immediately emits Status.Complete; when the stage yields Yield.None, Complete is skipped and the pipeline continues normally.

CompleteIfSome[I, O, E] returns a typed Decoration[I, O, E] that can be applied to any matching stage.

import h8io.stages.operators.*
import h8io.stages.projections.*

val stage = Unlift[Int]
// stage: h8io.stages.base.Projection[Option[Int], Int] = <function1>
val completing = CompleteIfSome[Option[Int], Int, Nothing](stage)
// completing: h8io.stages.Stage[Option[Int], Int, Nothing] = AndThen(
//   upstream = <function1>,
//   downstream = <function1>
// )

completing(Some(42))  // Unlift produces Some(42), Complete fires: Some(42, Complete, ...)
// res0: h8io.stages.Yield[Option[Int], Int, Nothing] = Some(
//   out = 42,
//   status = Complete(),
//   evolution = AndThen(upstream = <function1>, downstream = <function1>)
// )
completing(None)      // Unlift produces None, Complete skipped: None(Success, ...)
// res1: h8io.stages.Yield[Option[Int], Int, Nothing] = None(
//   status = Success,
//   evolution = AndThen(upstream = <function1>, downstream = <function1>)
// )