export declare const range: (size: number) => number[];
export declare const step: (x: number) => 1 | 0;
export declare const ramp: (x: number) => number;
export declare const xrange: (start: number, size: number) => number[];
export declare function optional<T>(fn: () => T, def?: T): T;
export declare function guid(): string;
export declare const randomString: (n: number) => string;