export declare const PullAfterAllEnqueued: <A>(emitSeparator: Option.Option<A>) => UpstreamPullStrategy<A>

export declare const PullAfterNext: <A>(emitSeparator: Option.Option<A>) => UpstreamPullStrategy<A>

export declare const match: {
  <A, Z>(options: {
    readonly onNext: (emitSeparator: Option.Option<A>) => Z
    readonly onAllEnqueued: (emitSeparator: Option.Option<A>) => Z
  }): (self: UpstreamPullStrategy<A>) => Z
  <A, Z>(
    self: UpstreamPullStrategy<A>,
    options: {
      readonly onNext: (emitSeparator: Option.Option<A>) => Z
      readonly onAllEnqueued: (emitSeparator: Option.Option<A>) => Z
    }
  ): Z
}

export interface PullAfterAllEnqueued<out A> extends UpstreamPullStrategy.Variance<A> {
  readonly _tag: "PullAfterAllEnqueued"
  readonly emitSeparator: Option.Option<A>
}

export interface PullAfterNext<out A> extends UpstreamPullStrategy.Variance<A> {
  readonly _tag: "PullAfterNext"
  readonly emitSeparator: Option.Option<A>
}

export type UpstreamPullStrategy<A> = PullAfterNext<A> | PullAfterAllEnqueued<A>

export declare const isPullAfterAllEnqueued: <A>(self: UpstreamPullStrategy<A>) => self is PullAfterAllEnqueued<A>

export declare const isPullAfterNext: <A>(self: UpstreamPullStrategy<A>) => self is PullAfterNext<A>

export declare const isUpstreamPullStrategy: (u: unknown) => u is UpstreamPullStrategy<unknown>

export declare const UpstreamPullStrategyTypeId: typeof UpstreamPullStrategyTypeId

export type UpstreamPullStrategyTypeId = typeof UpstreamPullStrategyTypeId

export interface Variance<out A> {
  readonly [UpstreamPullStrategyTypeId]: {
    readonly _A: Types.Covariant<A>
  }
}