/**
 * 空函数
 * @category 函数
 */
export declare const noop: (...args: any) => any;
/**
 * 是否为函数
 * @category 函数
 */
export declare function isFn(fn: unknown): fn is (...args: any) => any;
/**
 * 防抖函数
 *
 * ```ts
 * import { debounce } from 'sunny-js'
 * // 常规用法
 * document.addEventListener(
 *   'mousemove',
 *   debounce(function (e) {
 *     console.log(this, e)
 *   }, 350)
 * )
 * // 带有返回值
 * const _wrappedFn = debounce(
 *   (e: MouseEvent) => `clientX ${e.clientX}, clientY ${e.clientY}`,
 *   350
 * )
 * document.addEventListener('mousemove', e => {
 *   void _wrappedFn(e).then(console.log)
 * })
 * ```
 *
 * @category 函数
 */
export declare function debounce<TParams extends unknown[], TReturn = unknown, TContext = unknown>(fn: (this: TContext, ...args: TParams) => TReturn | Promise<TReturn>, wait: number): (this: TContext, ...args: TParams) => TReturn extends void ? void : Promise<TReturn>;
/**
 * 节流函数
 *
 * ```ts
 * import { throttle } from 'sunny-js'
 * // 常规用法
 * document.addEventListener(
 *   'mousemove',
 *   throttle(function (e) {
 *     console.log(this, e)
 *   }, 350)
 * )
 * ```
 *
 * @category 函数
 */
export declare function throttle<TParams extends unknown[], TContext = unknown>(fn: (this: TContext, ...args: TParams) => void, wait: number): (this: TContext, ...args: TParams) => void;
/**
 * 记忆函数
 *
 * ```ts
 * import { throttle } from 'sunny-js'
 * const _fn = memoize(function (...args) {
 *   console.log(['compute', this, ...args])
 *   return ['value', ...args]
 * })
 * console.log(_fn())
 * console.log(_fn())
 * console.log(_fn(console))
 * console.log(_fn(console))
 * console.log(_fn(1, 2))
 * console.log(_fn(1, 2))
 * console.log(_fn.cache)
 * ```
 *
 * @param fn 被包装的函数
 * @param resolver 返回值将作为cache key。默认resolver逻辑是：如果无参数，使用fn.toString()作为key；如果有一个参数，args[0]为key；如果参数个数大于1，JSON.stringify(args)作为key。
 * @see {@link https://www.sitepoint.com/implementing-memoization-in-javascript/ Implementing Memoization in JavaScript}
 * @see {@link https://lodash.com/docs/4.17.15#memoize lodash memoize}
 * @category 函数
 */
export declare function memoize<TParams extends unknown[], TReturn = unknown, TContext = unknown>(fn: (this: TContext, ...args: TParams) => TReturn, resolver?: (this: TContext, ...args: TParams) => any): {
    (this: TContext, ...args: TParams): TReturn;
    cache: Map<any, any>;
};
/**
 * 函数合并调用
 *
 * ```ts
 * import { combineFunctions } from 'sunny-js'
 * // 合并多个事件监听函数
 * document.addEventListener(
 *   'click',
 *   combineFunctions(
 *     function (e) {
 *       console.log(this, e)
 *     },
 *     function (e) {
 *       console.info(this, e)
 *     }
 *   )
 * )
 * // 使用函数的返回值
 * const combinedFn = combineFunctions<[], number | string>(
 *   () => 1,
 *   () => 'hello',
 *   () => 'world'
 * )
 * console.log(combinedFn())
 * ```
 *
 * @since 2.1.33
 * @category 函数
 */
export declare function combineFunctions<TArgs extends unknown[], TReturn = unknown, TContext = unknown>(...functions: Array<(this: TContext, ...args: TArgs) => TReturn>): (this: TContext, ...args: TArgs) => TReturn extends void ? void : TReturn[];