Cancel work

module

search.lucent.ts

import { delay } from "lucent:core";

export async function search(
  words: string[],
  query: string,
  signal: AbortSignal,
): Promise<string[]> {
  const found: string[] = [];
  for (let i = 0; i < words.length; i++) {
    if (i % 1000 === 0) {
      signal.throwIfAborted();
      await delay(0); // let other calls in between chunks
    }
    const word = words[i]!;
    if (word.includes(query)) found.push(word);
  }
  return found;
}

JS usage

App.tsx

const controller = new AbortController();
const results = search(words, "lu", controller.signal);

controller.abort(); // results rejects with an AbortError

Pass an AbortSignal from JavaScript. When JavaScript calls abort(), the signal is set in native code at once. Your code stops where it checks: signal.throwIfAborted(), or a delay(ms, signal).

• The rejection is an Error named AbortError, or the reason JavaScript passed to abort().
• signal.aborted reads the state, and signal.addEventListener("abort", …) runs a function when it's set.
• A signal can come into Lucent, but not go back out, and an AbortController can't cross at all.