zopu-code/repos/effect/.changeset/bold-planets-shout.md

effect

effect
patch

add support for merging external events into Prompt.custom render loops via an optional events dequeue and receive handler.

The prompt races user input against events from the dequeue, allowing background events to trigger re-renders without waiting for a keypress:

const eventQueue = yield * Queue.make<number>()

const prompt = Prompt.custom(
  { count: 0 },
  Queue.asDequeue(eventQueue), // <-- provide the event queue as a dequeue to the prompt
  {
    render: (state) => Effect.succeed(`Count: ${state.count}`),
    process: (input, state) =>
      Effect.succeed(
        Match.value(input).pipe(
          // handle user input
          Match.tag("Input", () => Action.Submit({ value: state.count })),
          // handle external events from the queue
          Match.tag("Event", (input) => Action.NextFrame({ state: { count: state.count + input.value } })),
          Match.exhaustive
        )
      ),
    clear: () => Effect.succeed("")
  }
)