import { TransformerFunction, TMap, AnyMap } from '../typings/utils';
/**
 * Transform an array of strings into an object, optionally
 * transforming values of keys and values.
 *
 * @example
 * Input: ['VARIABLE', 'VAR'], k => '_' + k
 * Output: { _VARIABLE: 'VARIABLE', _VAR: 'VAR' }
 *
 * @param array Function that returns string.
 * @param transformKey Function that transforms the object key.
 * @param transformValue Function that transforms the object value.
 */
export declare function stringArrayToMapping<T>(array?: string[], transformKey?: TransformerFunction<string>, transformValue?: TransformerFunction<T>): TMap<T>;
/**
 * Trim ends of string from chars given.
 * Default chars are whitespaces and tabs.
 *
 * @param string String to be trimmed.
 * @param additional Additional character list to trim.
 * @param chars Defult character list to trim.
 */
export declare function trimString(string: string, additional?: string, chars?: string): string;
/**
 * Return the same instance of object without
 * the properties containing null values.
 *
 * @param obj Object to be filtered.
 */
export declare function filterNullValues(obj: AnyMap): AnyMap;
/**
 * Test whether given value is array.
 *
 * @param value Value to be tested.
 */
export declare function isArray(value: any): value is any[];
/**
 * Test whether given value is string.
 *
 * @param value Value to be tested.
 */
export declare function isString(value: any): value is string;
/**
 * Test whether given value is number.
 *
 * @param value Value to be tested.
 */
export declare function isNumber(value: any): value is number;
/**
 * Test whether given value is function.
 *
 * @param value Value to be tested.
 */
export declare function isFunction(value: any): value is Function;
/**
 * Test whether given value is object.
 *
 * @param value Value to be tested.
 */
export declare function isObject(value: any): value is AnyMap;
/**
 * Test whether given value is defined and not null.
 *
 * @param value Value to be tested.
 */
export declare function isDefined<T>(value: T): value is NonNullable<T>;
/**
 * Set an enumarable, configurable and writable property of given target object.
 *
 * @param target Target object to have property set on.
 * @param key Property key.
 * @param value Property value.
 */
export declare function setProperty(target: any, key: string, value: any): void;