/**
 * Iterate over an iterable and run a closure on each item - as with `for ... of` - but do so
 * asynchronously and with minimal waits inserted after a configurable time interval.
 *
 * Intended for long-running or compute-intensive loops that would otherwise lock up the browser
 * if run synchronously. Waiting at regular intervals minimizes blocking of user interactions,
 * allowing ongoing rendering of UI updates (e.g. load masks) and generally keeping the browser
 * event loop running.
 *
 * Note that if the content tab is hidden (i.e. `!XH.pageIsVisible`) this loop will be executed
 * without pauses.  In this case the pauses would be unduly large due to throttling of the event
 * loop by the browser, and there is no user benefit to avoiding blocking the main thread.
 *
 * NOTE this is NOT for use cases where the `fn` arg is itself async - i.e. it does not await the
 * call to `fn` and is instead for the opposite use case, where fn is *synchronous*. If looking to
 * run an async operation over a collection, consider a simple and blocking for...of loop.
 */
export declare function forEachAsync<T>(collection: Iterable<T>, fn: (val: T, idx: number, collection: Iterable<T>) => void, opts?: {
    waitAfter?: number;
    waitFor?: number;
}): Promise<void>;
/**
 * As with `forEachAsync()` above, but in the form of a `while` loop.
 * @param conditionFn - called before each iteration; return true to continue loop.
 * @param fn - called without arguments for each iteration.
 * @param opts - additional options.
 */
export declare function whileAsync(conditionFn: () => boolean, fn: () => void, opts?: AsyncLoopOptions): Promise<void>;
export interface AsyncLoopOptions {
    /**
     * Interval in ms after which the loop should pause and wait. If the loop completes before
     * this interval has passed, no waits will be inserted. Default 50ms.
     */
    waitAfter?: number;
    /**
     * Wait time in ms for each pause. The default of 0ms should be sufficient to allow an event
     * loop cycle to run.
     */
    waitFor?: number;
}