import { EventStream } from 'event-stream-pubsub';
import type { QueueOrder } from '../../domain.objects/constants';
export interface Queue<T> {
    /**
     * add one or more items into the queue
     */
    push: (item: T | T[]) => void;
    /**
     * view the top items from the queue, without removing them
     *
     * note
     * - `.peek() === .peek(1) === .peek(0, 1)` -> view the top item
     * - `.peek(2) === .peek(0, 2)` -> view the top 2 items
     * - `.peek(2, 3)` -> view the top 2nd and 3rd items
     */
    peek: (start?: number, end?: number) => T[];
    /**
     * remove the top items from the queue
     *
     * note
     * - `.pop() === .pop(1) === .pop(0, 1)` -> remove the top item
     * - `.pop(2) === .pop(0, 2)` -> remove the top 2 items
     * - `.pop(2, 3)` -> remove the top 2nd and 3rd items
     */
    pop: (start?: number, end?: number) => T[];
    /**
     * the current number of items in the queue
     */
    length: number;
    /**
     * event streams that can be subscribed to
     */
    on: {
        push: Omit<EventStream<{
            items: T[];
        }>, 'publish'>;
        peek: EventStream<{
            items: T[];
        }>;
        pop: EventStream<{
            items: T[];
        }>;
    };
}
export declare const createQueue: <T>({ order }: {
    order: QueueOrder;
}) => Queue<T>;