import { DisplayObject } from '@antv/g';
export declare function identity<T>(x: T): T;
type Func<R> = (x: R, ...args: any[]) => R;
/**
 * Composes functions from left to right.
 */
export declare function compose<R>(fns: Func<R>[]): Func<R>;
/**
 * Composes single-argument async functions from left to right.
 */
export declare function composeAsync<R>(fns: ((x: R) => Promise<R> | R)[]): (x: R) => Promise<R> | R;
export declare function capitalizeFirst(str: string): string;
export declare function error(message?: string): never;
export declare function copyAttributes(target: DisplayObject, source: DisplayObject): void;
export declare function defined(x: any): boolean;
export declare function random(a: number, b: number): number;
export declare function useMemo<T = unknown, U = unknown>(compute: (key: T) => U): (key: T) => U;
export declare function appendTransform(node: DisplayObject, transform: any): void;
export declare function subObject(obj: Record<string, any>, prefix: string): Record<string, any>;
export declare function maybeSubObject(obj: Record<string, any>, prefix: string): Record<string, any>;
export declare function prefixObject(obj: Record<string, any>, prefix: string): Record<string, any>;
export declare function filterPrefixObject(obj: Record<string, any>, prefix: string[]): Record<string, any>;
export declare function omitPrefixObject(obj: Record<string, any>, ...prefixes: string[]): {
    [k: string]: any;
};
export declare function maybePercentage(x: number | string, size: number): number;
export declare function isStrictObject(d: any): boolean;
export declare function isUnset(value: any): boolean;
export {};