/**
 * Defines a comparator function which can be used for sorting items.
 */
export type Comparator<T> = (a: T, b: T) => -1 | 0 | 1;
/**
 * Creates a new combined {@link Comparator<T>} which sorts items by the given comparators.
 * The comparators are applied in the order they are given (left -> right).
 *
 * @param comparators the comparators to use for sorting.
 * @returns a combined {@link Comparator<T>}.
 */
export declare const combineComparators: <T>(...comparators: Comparator<T>[]) => Comparator<T>;
/**
 * Creates a new comparator which sorts items in descending order.
 *
 * @example
 * const byValue = (a, b) => a < b ? - 1 : a > b ? 1 : 0;
 * const byValueDesc = descending(byValue);
 *
 * @param comparator the comparator to wrap.
 */
export declare const descending: <T>(comparator: Comparator<T>) => Comparator<T>;
/**
 * Creates a new comparator which conditionally applies the given comparator.
 *
 * @example
 * const shouldSortByValue = (a, b) => a % 2 === 0; // return false to turn it off
 * const byValue = (a, b) => a < b ? - 1 : a > b ? 1 : 0;
 * const comparator = conditional(shouldSortByValue)(byValue);
 *
 * @param predicate the predicate to use for determining whether to apply the comparator.
 */
export declare const conditional: <T>(predicate: (a: T, b: T) => boolean) => (comparator: Comparator<T>) => Comparator<T>;
/**
 * A no-op comparator which always returns 0.
 */
export declare const noopComparator: <T>() => Comparator<T>;