effect-io-ai

Package: effect
Module: Effect

Effect.catchEager

Applies catch eagerly when an effect is already resolved.

When to use

Use when an already-resolved failed effect should recover immediately while pending effects still use regular error recovery.

Details

Success effects pass through unchanged because there is no error to catch. Failure effects apply the catch function immediately, and pending effects fall back to regular catch behavior.

Example (Catching failures eagerly when possible)

import { Effect } from "effect"

// For resolved failure effects, the catch function is applied immediately
const failed = Effect.fail("original error")
const recovered = Effect.catchEager(
  failed,
  (err: string) => Effect.succeed(`recovered from: ${err}`)
) // Applied eagerly

// For success effects, returns success as-is
const success = Effect.succeed(42)
const unchanged = Effect.catchEager(
  success,
  (err: string) => Effect.succeed(`recovered from: ${err}`)
) // Returns success as-is

// For pending effects, behaves like regular catch
const pending = Effect.delay(Effect.fail("error"), "100 millis")
const recoveredPending = Effect.catchEager(
  pending,
  (err: string) => Effect.succeed(`recovered from: ${err}`)
) // Uses regular catch

Signature

declare const catchEager: { <E, B, E2, R2>(f: (e: NoInfer<E>) => Effect<B, E2, R2>): <A, R>(self: Effect<A, E, R>) => Effect<A | B, E2, R | R2>; <A, E, R, B, E2, R2>(self: Effect<A, E, R>, f: (e: NoInfer<E>) => Effect<B, E2, R2>): Effect<A | B, E2, R | R2>; }

Source

Since v4.0.0