Function timeout

Ends iteration after a specified number of milliseconds (from the beginning of iteration). When ms < 0, the timeout is deactivated.

Optional callback cb is invoked when timeout is reached before iteration is over.

import {pipe, toAsync, delay, timeout} from 'iter-ops';

const i = pipe(
           toAsync([1, 2, 3, 4]),
           delay(10), // an async operation that takes 10ms each
           timeout(18, (count) => {
               // timeout occurred (failed to process all items);
               // only 'count' number of items were processed.
           })
         );

(async function() {
    for await(const a of i) {
        console.log(a); //=> 1, 2
    }
})();

// We never get 3, 4 above, as iteration times out after 18ms.
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It works synchronously in a similar way:

import {pipe, tap, timeout} from 'iter-ops';

const i = pipe(
           [1, 2, 3, 4],
           tap(() => {
               sleep(5); // artificially delaying each iteration step
           }),
           timeout(8)
         );

console.log(...i); //=> 1, 2 (we never get 3, 4 due to the timeout)

// sync sleep helper (without CPU load):
function sleep(t: number) {
    const arr = new Int32Array(new SharedArrayBuffer(4));
    Atomics.wait(arr, 0, 0, Math.max(1, t | 0));
}
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Note that the examples above may not always produce a consistent result, as they rely on a race condition, which depends on the OS, your current CPU load and JavaScript engine.

See

• delay