Class MicroScopeImpl

packages/effect/src/Micro.ts:3317–3378

export const MicroScope: Context.Tag<MicroScope, MicroScope> = Context.GenericTag<MicroScope>("effect/Micro/MicroScope")

class MicroScopeImpl implements MicroScope.Closeable {
  readonly [MicroScopeTypeId]: MicroScopeTypeId
  state: {
    readonly _tag: "Open"
    readonly finalizers: Set<(exit: MicroExit<any, any>) => Micro<void>>
  } | {
    readonly _tag: "Closed"
    readonly exit: MicroExit<any, any>
  } = { _tag: "Open", finalizers: new Set() }

  constructor() {
    this[MicroScopeTypeId] = MicroScopeTypeId
  }

  unsafeAddFinalizer(finalizer: (exit: MicroExit<any, any>) => Micro<void>): void {
    if (this.state._tag === "Open") {
      this.state.finalizers.add(finalizer)
    }
  }
  addFinalizer(finalizer: (exit: MicroExit<any, any>) => Micro<void>): Micro<void> {
    return suspend(() => {
      if (this.state._tag === "Open") {
        this.state.finalizers.add(finalizer)
        return void_
      }
      return finalizer(this.state.exit)
    })
  }
  unsafeRemoveFinalizer(finalizer: (exit: MicroExit<any, any>) => Micro<void>): void {
    if (this.state._tag === "Open") {
      this.state.finalizers.delete(finalizer)
    }
  }
  close(microExit: MicroExit<any, any>): Micro<void> {
    return suspend(() => {
      if (this.state._tag === "Open") {
        const finalizers = Array.from(this.state.finalizers).reverse()
        this.state = { _tag: "Closed", exit: microExit }
        return flatMap(
          forEach(finalizers, (finalizer) => exit(finalizer(microExit))),
          exitVoidAll
        )
      }
      return void_
    })
  }
  get fork() {
    return sync(() => {
      const newScope = new MicroScopeImpl()
      if (this.state._tag === "Closed") {
        newScope.state = this.state
        return newScope
      }
      function fin(exit: MicroExit<any, any>) {
        return newScope.close(exit)
      }
      this.state.finalizers.add(fin)
      newScope.unsafeAddFinalizer((_) => sync(() => this.unsafeRemoveFinalizer(fin)))