import { Obj } from '@mathigon/core';
declare global {
    interface Window {
        csrfToken: string;
    }
}
type PostData = Obj<string | number | boolean | string[] | number[] | boolean[]>;
/** Converts a JSON object to an HTML query string. */
export declare function toQueryString(data: PostData): string;
/** Converts an HTML query string to JSON object. */
export declare function fromQueryString(str: string): Obj<string>;
/**
 * Asynchronously loads a resource using a POST request. This utility function
 * automatically form-encodes JSON data and adds a CSRF header.
 */
export declare function post(url: string, data?: FormData | PostData): Promise<string>;
/** Asynchronously loads and executes a JS script. */
export declare function loadScript(src: string): Promise<unknown>;
/** Asynchronously loads an Image. */
export declare function loadImage(url: string, credentials?: boolean): Promise<HTMLImageElement>;
export declare const loadImageDataURI: (url: string) => Promise<string>;
/**
 * Utility function to throttle repeated POST requests. A request to the same
 * URL will be made at most every 5s, and the corresponding data objects will
 * be deep-merged.
 */
export declare function deferredPost(url: string, data: PostData): void;
export {};