/** Returns whether bundler-injected variable `NODE_ENV` equals `env`. */
export declare function isNodeEnv(env: string): boolean;
/**
 * Returns the difference in length between two arrays. A `null` argument is
 * considered an empty list. The return value will be positive if `a` is longer
 * than `b`, negative if the opposite is true, and zero if their lengths are
 * equal.
 */
export declare function arrayLengthCompare(a?: any[], b?: any[]): number;
/**
 * Returns true if the two numbers are within the given tolerance of each other.
 * This is useful to correct for floating point precision issues, less useful
 * for integers.
 */
export declare function approxEqual(a: number, b: number, tolerance?: number): boolean;
/**
 * Clamps the given number between min and max values. Returns value if within
 * range, or closest bound.
 */
export declare function clamp(val: number, min: number, max: number): number;
/** Returns the number of decimal places in the given number. */
export declare function countDecimalPlaces(num: number): number;
/** Generate a unique ID within a given namespace, using a simple counter-based implementation to avoid collisions. */
export declare function uniqueId(namespace: string): string;
/**
 * @returns `true` if the value is an empty string after trimming whitespace
 */
export declare function isEmptyString(val: any): boolean;