import { Resolvable, Promise } from '../promise';
export declare type LockHandler<TResult> = () => Resolvable<TResult>;
/**
 * `Lock` class is a useful helper that can act as a simple task queue.
 */
export declare class Lock {
    private _promise;
    /**
     * Handler will be called once the return value of previous queued handler
     * gets settled.
     * @param handler Queue handler.
     * @return Created promise, will be settled once the handler throws an
     *     error or the return value of the handler gets settled.
     */
    queue<TResult>(handler: LockHandler<TResult>): Promise<TResult>;
    /**
     * Handler will be called if there's no queued ones.
     * @param handler Try handler.
     * @return Created promise, will be settled once the handler throws an
     *     error or the return value of the handler gets settled.
     */
    try<TResult>(handler: LockHandler<TResult>): Promise<TResult>;
    /**
     * (get) A function that binds `queue` method with current instance.
     */
    readonly queuer: <TResult>(handler: LockHandler<TResult>) => Promise<TResult>;
    /**
     * (get) A function that binds `try` method with current instance.
     */
    readonly trier: <TResult>(handler: LockHandler<TResult>) => Promise<TResult>;
}