effect-io-ai

Package: effect
Module: Deferred

Deferred.sync

Computes a value when the returned effect is run, then attempts to complete the Deferred with that value.

When to use

Use to lazily compute a successful value when the Deferred completion effect runs.

Details

Fibers waiting on the Deferred receive the computed value only if this call completes it. The returned effect succeeds with true when this call completed the Deferred, or false if it was already completed.

Example (Completing a Deferred with a lazy value)

import { Deferred, Effect } from "effect"

const program = Effect.gen(function*() {
  const deferred = yield* Deferred.make<number>()
  yield* Deferred.sync(deferred, () => 42)

  const value = yield* Deferred.await(deferred)
  console.log(value) // 42
})

Signature

declare const sync: { <A>(evaluate: LazyArg<A>): <E>(self: Deferred<A, E>) => Effect<boolean>; <A, E>(self: Deferred<A, E>, evaluate: LazyArg<A>): Effect<boolean>; }

Source

Since v2.0.0