effect-io-ai

Package: effect
Module: LayerRef

LayerRef.Service

Creates a service class for a LayerRef.

When to use

Use when you want to name a shared layer reference as an application service and expose static helpers for providing, retrieving, and invalidating it.

Details

The returned class is a Context.Service whose value is a LayerRef. It also includes .layer, .layerNoDeps, .get, .contextEffect, and .invalidate helpers so callers do not need to access the LayerRef value directly.

Example (Defining a refreshable service)

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

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

const databaseLayer = Layer.succeed(Database, {
  query: Effect.succeed("result")
})

class DatabaseRef extends LayerRef.Service<DatabaseRef>()("DatabaseRef", {
  layer: databaseLayer,
  preload: true
}) {}

const program = Effect.gen(function*() {
  const database = yield* Database
  return yield* database.query
}).pipe(
  Effect.provide(DatabaseRef.get),
  Effect.provide(DatabaseRef.layer)
)

See

• make for creating a LayerRef value without defining a service class

Signature

declare const Service: <Self>() => <const Id extends string, I, E, R, X, const Deps extends ReadonlyArray<Layer.Layer<any, any, any>> = [], const Preload extends boolean = never, SE = never, SR = never>(id: Id, options: { readonly layer: Layer.Layer<I, E, R>; readonly dependencies?: Deps | undefined; readonly idleTimeToLive?: Duration.Input | undefined; readonly preload?: Preload | undefined; readonly invalidationSchedule?: Schedule.Schedule<X, unknown, SE, SR> | undefined; }) => TagClass<Self, Id, I, E, R | SR, [Preload] extends [true] ? E : never, Deps[number]>

Source

Since v4.0.0