effect-io-ai

Package: effect
Module: Layer

Layer.effect

Constructs a layer from an effect that produces a single service.

When to use

Use when you need to construct a Layer-provided service with an Effect, dependencies, or scoped resource acquisition.

Details

This allows you to create a Layer from an Effect that produces a service. The Effect is executed in the scope of the layer, allowing for proper resource management.

Example (Creating a layer from an effect)

import { Context, Effect, Layer } from "effect"

class Database extends Context.Service<Database, {
  readonly query: (sql: string) => Effect.Effect<string>
}>()("Database") {}

const layer = Layer.effect(Database,
  Effect.sync(() => ({
    query: (sql: string) => Effect.succeed(`Query: ${sql}`)
  }))
)

See

• effectContext for effectfully providing multiple services
• effectDiscard for running construction work without providing services

Signature

declare const effect: { <I, S>(service: Context.Key<I, S>): <E, R>(effect: Effect<S, E, R>) => Layer<I, E, Exclude<R, Scope.Scope>>; <I, S, E, R>(service: Context.Key<I, S>, effect: Effect<Types.NoInfer<S>, E, R>): Layer<I, E, Exclude<R, Scope.Scope>>; }

Source

Since v2.0.0