import * as Effect from "effect/Effect";import * as PubSub from "effect/PubSub";import * as Semaphore from "effect/Semaphore";import * as Stream from "effect/Stream"; export interface SnapshotSubscription<A> {  readonly latest: A;  readonly changes: Stream.Stream<A>;} export const subscribeBeforeSnapshot = Effect.fn("subscribeBeforeSnapshot")(function* <A, E, R>(  changes: PubSub.PubSub<A>,  snapshot: Effect.Effect<A, E, R>,  mutex: Semaphore.Semaphore,) {  return yield* mutex.withPermits(1)(    Effect.gen(function* () {      const latest = yield* snapshot;      const subscription = yield* PubSub.subscribe(changes);      return {        latest,        changes: Stream.fromSubscription(subscription),      } satisfies SnapshotSubscription<A>;    }),  );}); export const subscribeBeforeSnapshotWithoutMutex = Effect.fn("subscribeBeforeSnapshotWithoutMutex")(  function* <A, E, R>(changes: PubSub.PubSub<A>, snapshot: Effect.Effect<A, E, R>) {    const subscription = yield* PubSub.subscribe(changes);    const latest = yield* snapshot;    return {      latest,      changes: Stream.fromSubscription(subscription),    } satisfies SnapshotSubscription<A>;  },);