Creates a scoped run function that forks effects into a new FiberMap and returns a Promise for each effect result.

When to use

Use when keyed fibers must be managed in a scoped map while exposing their results through Promise-based APIs.

Details

Each call stores the fiber under the supplied key, interrupting any previous fiber for that key unless onlyIfMissing is set. The returned Promise resolves with the effect's success value or rejects with the squashed failure cause.

Example (Creating a promise runtime)

import { Effect, FiberMap } from "effect"

const program = Effect.gen(function*() {
  const run = yield* FiberMap.makeRuntimePromise<never, string>()

  // Run effects and get back promises
  const promise1 = run("task1", Effect.succeed("Hello"))
  const promise2 = run("task2", Effect.succeed("World"))

  // Convert to Effect and await
  const result1 = yield* Effect.promise(() => promise1)
  const result2 = yield* Effect.promise(() => promise2)

  console.log(result1, result2) // "Hello", "World"
})