/**
 * @file Regular expression utilities
 */
export declare const REGEX_START = "^";
export declare const REGEX_END = "$";
export declare const REGEX_ANY_CHARACTERS: string;
export declare const ADBLOCK_URL_START: string;
export declare const ADBLOCK_URL_START_REGEX = "^(http|https|ws|wss)://([a-z0-9-_.]+\\.)?";
export declare const ADBLOCK_URL_SEPARATOR = "^";
export declare const ADBLOCK_URL_SEPARATOR_REGEX = "([^ a-zA-Z0-9.%_-]|$)";
export declare const ADBLOCK_WILDCARD = "*";
export declare const ADBLOCK_WILDCARD_REGEX: string;
export declare const REGEX_NEGATION_PREFIX = "^((?!";
export declare const REGEX_NEGATION_SUFFIX = ").)*$";
/**
 * Special RegExp symbols
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Regular_Expressions#special-escape
 */
export declare const SPECIAL_REGEX_SYMBOLS: Set<string>;
/**
 * Utility functions for working with RegExp patterns
 */
export declare class RegExpUtils {
    /**
     * Checks whether a string possibly is a RegExp pattern.
     * Flags are not supported.
     *
     * Note: it does not perform a full validation of the pattern,
     * it just checks if the string starts and ends with a slash.
     *
     * @param pattern - Pattern to check
     * @returns `true` if the string is a RegExp pattern, `false` otherwise
     */
    static isRegexPattern(pattern: string): boolean;
    /**
     * Checks whether a string is a negated RegExp pattern.
     *
     * @param pattern - Pattern to check
     * @returns `true` if the string is a negated RegExp pattern, `false` otherwise
     */
    static isNegatedRegexPattern(pattern: string): boolean;
    /**
     * Removes negation from a RegExp pattern.
     *
     * @param pattern - RegExp pattern to remove negation from
     * @returns RegExp pattern without negation
     */
    static removeNegationFromRegexPattern(pattern: string): string;
    /**
     * Negates a RegExp pattern. Technically, this method wraps the pattern in `^((?!` and `).)*$`.
     *
     * RegExp modifiers are not supported.
     *
     * @param pattern Pattern to negate (can be wrapped in slashes or not)
     * @returns Negated RegExp pattern
     */
    static negateRegexPattern(pattern: string): string;
    /**
     * Ensures that a pattern is wrapped in slashes.
     *
     * @param pattern Pattern to ensure slashes for
     * @returns Pattern with slashes
     */
    static ensureSlashes(pattern: string): string;
    /**
     * Converts a basic adblock rule pattern to a RegExp pattern. Based on
     * https://github.com/AdguardTeam/tsurlfilter/blob/9b26e0b4a0e30b87690bc60f7cf377d112c3085c/packages/tsurlfilter/src/rules/simple-regex.ts#L219
     *
     * @param pattern Pattern to convert
     * @returns RegExp equivalent of the pattern
     * @see {@link https://kb.adguard.com/en/general/how-to-create-your-own-ad-filters#basic-rules}
     */
    static patternToRegexp(pattern: string): string;
}