export declare const REGEX_SPECIAL_CHARS: RegExp;
/**
 * escape a string to be included in a regular expression.
 *
 * Characters that match REGEX_SPECIAL_CHARS will be prefixed with a backslash
 * preventing their special meaning.
 * NOTE: When using this function, the context of the regex being formed is
 * important. For example, a regex formed as:
 * ```
 * new RegExp("\\" + escape("w"))
 * ```
 * ends up creating the expression, `/\w/`.
 *
 * To avoid unforseen, subtle bugs, keep regular expressions generated from user
 * input simple.
 */
export declare const escape: (str: string) => string;