/**
 * Functions to be used in {@link Array.prototype.sort} as a callback.
 * @see https://pavel-surinin.github.io/declarativejs/#/?id=sorters
 */
export declare namespace Sort {
    interface IfAHigherB {
        true: number;
        false: number;
    }
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.
     * Sorts array in ascending order by values provided from callbacks.
     * First callback has highest priority in sorting and so on.
     * It accepts as many callbacks as You need.
     * @param {...Function} getters     functions to get values to be compared
     * @returns a closure that can be used in array.sort() function
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=ascendingby
     */
    function ascendingBy<T>(...getters: ((val: T) => string | number)[]): (a: T, b: T) => number;
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.
     * Sorts array in ascending order by values resolved from object keys passed
     * as parameter.
     * First key has highest priority in sorting and so on.
     * It accepts as many keys as You need.
     * @param {...string} keys     functions to get values to be compared
     * @returns a closure that can be used in array.sort() function
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=ascendingby
     */
    function ascendingBy<T, K extends keyof T>(...keys: K[]): (a: T, b: T) => number;
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.     *
     * Sorts array in descending order by values provided from callbacks.
     * First callback has highest priority in sorting and so on.
     * It accepts as many callbacks as You need.
     * @param {...Function} getters     functions to get values to be compared
     * @returns a closure that can be used in array.sort() function
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=descendingby
     */
    function descendingBy<T>(...getters: ((val: T) => string | number)[]): (a: T, b: T) => number;
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.
     * Sorts array in descending order by values resolved from object keys passed
     * as parameter.
     * First key has highest priority in sorting and so on.
     * It accepts as many keys as You need.
     * @param {...string} keys     functions to get values to be compared
     * @returns a closure that can be used in array.sort() function
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=descendingby
     */
    function descendingBy<T, K extends keyof T>(...keys: K[]): (a: T, b: T) => number;
    interface SortingCondition<T, R> {
        toValue: (val: T) => R;
        order: R[];
    }
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.
     * Function that will sort items in array with custom values, by provided order.
     * It accepts as a parameter object with valueToOrderElement mapper and array of custom order rule
     * @type T type of array item
     * @type R type of item that will be mapped from callback and will be compared
     * @param {toValue: function(T): R, R[]} ...conditions
     * @returns comparator for Array.prototype.sort function.
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=by
     */
    function by<T>(...conditions: SortingCondition<T, any>[]): (a: T, b: T) => number;
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.
     * Function that will sort items in array with custom values, by provided order.
     * @param {string} key              object key to extract value. This value will
     *                                  be compared to another
     * @param {string | number} values  values that will be define order of
     *                                  extracted value by key
     * @returns comparator for Array.prototype.sort function.
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=by
     */
    function by<T, K extends keyof T>(key: K, values: T[K][]): (a: T, b: T) => number;
    /**
     * Functions to be used in {@link Array.prototype.sort} as a callback.
     * Function that will sort items in array, by provided order.
     * It accepts as a parameter array of custom order rule.
     * Element, that are not present in order array will be at he the end of the sorted list.
     * @param order     array of custom order of items that are being sorted.
     * @returns comparator for Array.prototype.sort function.
     * @see https://pavel-surinin.github.io/declarativejs/#/?id=orderedby
     */
    function orderedBy<T>(order: T[]): (a: T, b: T) => 0 | 1 | -1;
}