effect-io-ai

Package: effect
Module: Deferred

Deferred.failCauseSync

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

When to use

Use to lazily compute a full failure cause when the Deferred completion effect runs.

Details

Fibers waiting on the Deferred observe the computed cause 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 (Failing a Deferred with a lazy Cause)

import { Cause, Deferred, Effect } from "effect"

const program = Effect.gen(function*() {
  const deferred = yield* Deferred.make<number, string>()
  const success = yield* Deferred.failCauseSync(
    deferred,
    () => Cause.fail("Lazy error")
  )
  console.log(success) // true
})

Signature

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

Source

Since v2.0.0