/*!
 * Copyright 2016 The ANTLR Project. All rights reserved.
 * Licensed under the BSD-3-Clause license. See LICENSE file in the project root for license information.
 */
/**
 * A generic set of integers.
 *
 * @see IntervalSet
 */
export interface IntSet {
    /**
     * Adds the specified value to the current set.
     *
     * @param el the value to add
     *
     * @exception IllegalStateException if the current set is read-only
     */
    add(el: number): void;
    /**
     * Modify the current {@link IntSet} object to contain all elements that are
     * present in itself, the specified `set`, or both.
     *
     * @param set The set to add to the current set. An `undefined` argument is
     * treated as though it were an empty set.
     * @returns `this` (to support chained calls)
     *
     * @exception IllegalStateException if the current set is read-only
     */
    addAll(/*@Nullable*/ set: IntSet): IntSet;
    /**
     * Return a new {@link IntSet} object containing all elements that are
     * present in both the current set and the specified set `a`.
     *
     * @param a The set to intersect with the current set.
     * @returns A new {@link IntSet} instance containing the intersection of the
     * current set and `a`.
     */
    and(a: IntSet): IntSet;
    /**
     * Return a new {@link IntSet} object containing all elements that are
     * present in `elements` but not present in the current set. The
     * following expressions are equivalent for input non-`undefined` {@link IntSet}
     * instances `x` and `y`.
     *
     * * `x.complement(y)`
     * * `y.subtract(x)`
     *
     * @param elements The set to compare with the current set.
     * @returns A new {@link IntSet} instance containing the elements present in
     * `elements` but not present in the current set.
     */
    complement(elements: IntSet): IntSet;
    /**
     * Return a new {@link IntSet} object containing all elements that are
     * present in the current set, the specified set `a`, or both.
     *
     * This method is similar to {@link #addAll(IntSet)}, but returns a new
     * {@link IntSet} instance instead of modifying the current set.
     *
     * @param a The set to union with the current set. An `undefined` argument
     * is treated as though it were an empty set.
     * @returns A new {@link IntSet} instance containing the union of the current
     * set and `a`. The value `undefined` may be returned in place of an
     * empty result set.
     */
    or(/*@Nullable*/ a: IntSet): IntSet;
    /**
     * Return a new {@link IntSet} object containing all elements that are
     * present in the current set but not present in the input set `a`.
     * The following expressions are equivalent for input non-`undefined`
     * {@link IntSet} instances `x` and `y`.
     *
     * * `y.subtract(x)`
     * * `x.complement(y)`
     *
     * @param a The set to compare with the current set. A `undefined`
     * argument is treated as though it were an empty set.
     * @returns A new {@link IntSet} instance containing the elements present in
     * `elements` but not present in the current set. The value
     * `undefined` may be returned in place of an empty result set.
     */
    subtract(/*@Nullable*/ a: IntSet): IntSet;
    /**
     * Return the total number of elements represented by the current set.
     *
     * @returns the total number of elements represented by the current set,
     * regardless of the manner in which the elements are stored.
     */
    readonly size: number;
    /**
     * Returns `true` if this set contains no elements.
     *
     * @returns `true` if the current set contains no elements; otherwise,
     * `false`.
     */
    readonly isNil: boolean;
    /**
     * {@inheritDoc}
     */
    equals(obj: any): boolean;
    /**
     * Returns `true` if the set contains the specified element.
     *
     * @param el The element to check for.
     * @returns `true` if the set contains `el`; otherwise `false`.
     */
    contains(el: number): boolean;
    /**
     * Removes the specified value from the current set. If the current set does
     * not contain the element, no changes are made.
     *
     * @param el the value to remove
     *
     * @exception IllegalStateException if the current set is read-only
     */
    remove(el: number): void;
    /**
     * Return an array containing the elements represented by the current set. The
     * array is returned in ascending numerical order.
     *
     * @returns An array containing all element present in the current set, sorted
     * in ascending numerical order.
     */
    toArray(): number[];
    /**
     * {@inheritDoc}
     */
    toString(): string;
}