/**
 * Creates a `RegExp` using a string template. Supports flags.
 *
 * @example
 *
 * ```ts
 * const regex = re`/abc/g`
 * ```
 */
export declare function re(strings: TemplateStringsArray, ...keys: any[]): RegExp;
/**
 * Helper for checking if a `Set`, `Array`, or `string` contains another
 * `string`. Handles undefined or null inputs by returning false.
 *
 * @param value - The value to check for.
 * @param container - The container of strings (or another string).
 */
export declare function includes(value: string | undefined | null, container: Set<string> | string[] | string | undefined | null): boolean;
/** Takes a string and escapes any `RegExp` sensitive characters. */
export declare function escapeRegExp(str: string): string;
/**
 * Replaces a range inside of a string with a substitute.
 *
 * @param str - The string which should have a range inside of it replaced.
 * @param from - The start of the replacement range.
 * @param to - The end of the replacement range.
 * @param sub - The replacement/substitute string.
 */
export declare function replaceRange(str: string, from: number, to: number, sub: string): string;
/**
 * Uppercases a string.
 *
 * @param str - The string to uppercase.
 * @param locale - Uses a locale, or a list of locales, case mapping if
 *   provided. This usually won't be needed, as JS tries to account for
 *   non-ASCII/Latin text when handling casing.
 */
export declare function uppercase(str: string, locale?: string | string[]): string;
/**
 * Lowercases a string.
 *
 * @param str - The string to lowercase.
 * @param locale - Uses a locale, or a list of locales, case mapping if
 *   provided. This usually won't be needed, as JS tries to account for
 *   non-ASCII/Latin text when handling casing.
 */
export declare function lowercase(str: string, locale?: string | string[]): string;
/**
 * Titlecases a string.
 *
 * @param str - The string to titlecase.
 * @param locale - Uses a locale, or a list of locales, case mapping if
 *   provided. This usually won't be needed, as JS tries to account for
 *   non-ASCII/Latin text when handling casing.
 */
export declare function titlecase(str: string, locale?: string | string[]): string;
/**
 * Determines if a string is titlecased.
 *
 * @param str - The string to check.
 * @param locale - Uses a locale, or a list of locales, case mapping if
 *   provided. This usually won't be needed, as JS tries to account for
 *   non-ASCII/Latin text when handling casing.
 */
export declare function isTitlecased(str: string, locale?: string | string[]): boolean;
/**
 * Determines if a string is completely uppercased.
 *
 * @param str - The string to check.
 * @param locale - Uses a locale, or a list of locales, case mapping if
 *   provided. This usually won't be needed, as JS tries to account for
 *   non-ASCII/Latin text when handling casing.
 */
export declare function isUppercased(str: string, locale?: string | string[]): boolean;
/**
 * Determines if a string is completely lowercased.
 *
 * @param str - The string to check.
 * @param locale - Uses a locale, or a list of locales, case mapping if
 *   provided. This usually won't be needed, as JS tries to account for
 *   non-ASCII/Latin text when handling casing.
 */
export declare function isLowercased(str: string, locale?: string | string[]): boolean;
/**
 * Reverses a string.
 *
 * @param str - The string to reverse.
 */
export declare function reverse(str: string): string;
/** Splits a line by its whitespace. */
export declare function split(line: string): string[];
/**
 * Returns true if the given string 3 characters and all characters are the same.
 *
 * @param s - The string to check.
 */
export declare function isTriplet(s: string): boolean;
/**
 * Returns a new set containing all intersecting elements between two sets.
 *
 * @param a - The first set.
 * @param b - The second set.
 */
export declare function intersect<T>(a: Set<T>, b: Set<T>): Set<T>;
export declare function concat(a: string, b: Iterable<string>): string;
export declare function concat<T>(a: Set<T>, b: Iterable<T>): Set<T>;
export declare function concat<T>(a: T[], b: Iterable<T>): T[];
export declare function product<T>(...iterables: Iterable<T>[]): Generator<T[]>;
/** Returns true if the given iterator yields literally anything. */
export declare function any(gen: Iterable<unknown>): boolean;
/**
 * Limits an iterator to the specified count.
 *
 * @param gen - The iterator to limit. param n - The number of elements to limit to.
 */
export declare function limit<T>(gen: Iterable<T>, n: number): Iterable<T>;
/**
 * Returns the number of characters common between two strings, in both
 * type and position.
 */
export declare function commonCharacters(s1: string, s2: string): number;
/** Returns the amount of characters in common between the left-sides of two strings. */
export declare function leftCommonSubstring(s1: string, s2: string): number;
/**
 * Returns the number of ngrams of `s1` are in `s2`. Higher is better.
 *
 * @param max - The `n` in `ngram`.
 * @param s1 - String to compare against `s2`.
 * @param s2 - String to compare against `s1`.
 * @param weighted - Reduce score depending on number ngrams *not contained* in `s2`.
 * @param longerIsWorse - Reduce score when `s2` is longer than `s1`.
 * @param anyMismatch - Reduce score if the strings differ in length at all.
 */
export declare function ngram(max: number, s1: string, s2: string, weighted?: boolean, anyMismatch?: boolean, longerIsWorse?: boolean): number;
/** Length of the "longest common subsequence" in two strings. */
export declare function lcslen(a: string, b: string): number;