effect-io-ai

Package: effect
Module: RcMap

RcMap.make

An RcMap can contain multiple reference counted resources that can be indexed by a key. The resources are lazily acquired on the first call to get and released when the last reference is released.

Complex keys can extend Equal and Hash to allow lookups by value.

Options

• capacity: The maximum number of resources that can be held in the map.
• idleTimeToLive: When the reference count reaches zero, the resource will be released after this duration.

Example

import { Effect, RcMap } from "effect"

Effect.gen(function*() {
  const map = yield* RcMap.make({
    lookup: (key: string) =>
      Effect.acquireRelease(
        Effect.succeed(`acquired ${key}`),
        () => Effect.log(`releasing ${key}`)
      )
  })

  // Get "foo" from the map twice, which will only acquire it once.
  // It will then be released once the scope closes.
  yield* RcMap.get(map, "foo").pipe(
    Effect.andThen(RcMap.get(map, "foo")),
    Effect.scoped
  )
})

Signature

declare const make: { <K, A, E, R>(options: { readonly lookup: (key: K) => Effect.Effect<A, E, R>; readonly idleTimeToLive?: Duration.DurationInput | undefined; readonly capacity?: undefined; }): Effect.Effect<RcMap<K, A, E>, never, Scope.Scope | R>; <K, A, E, R>(options: { readonly lookup: (key: K) => Effect.Effect<A, E, R>; readonly idleTimeToLive?: Duration.DurationInput | undefined; readonly capacity: number; }): Effect.Effect<RcMap<K, A, E | Cause.ExceededCapacityException>, never, Scope.Scope | R>; }

Source

Since v3.5.0