effect-io-ai

Package: effect
Module: SubscriptionRef

SubscriptionRef.getAndUpdate

Retrieves the current value and updates it atomically with the result of applying a function, notifying subscribers of the change.

Example (Getting and updating a value)

import { Effect, SubscriptionRef } from "effect"

const program = Effect.gen(function*() {
  const ref = yield* SubscriptionRef.make(10)

  const oldValue = yield* SubscriptionRef.getAndUpdate(ref, (n) => n * 2)
  console.log("Old value:", oldValue)

  const newValue = yield* SubscriptionRef.get(ref)
  console.log("New value:", newValue)
})

Signature

declare const getAndUpdate: { <A>(update: (a: A) => A): (self: SubscriptionRef<A>) => Effect.Effect<A>; <A>(self: SubscriptionRef<A>, update: (a: A) => A): Effect.Effect<A>; }

Source

Since v2.0.0