/** Decimal digits 0-9. */ export declare const DIGITS: string;
/** Octal digits 0-7. */ export declare const OCT_DIGITS: string;
/** Hexadecimal digits 0-9, A-F, a-f. */ export declare const HEX_DIGITS: string;
/** English letters A-Z. */ export declare const UPPERCASE: string;
/** English letters a-z. */ export declare const LOWERCASE: string;
/** Combination of uppercase, lowercase english letters. */ export declare const LETTERS: string;
/** Punctuation symbols (ASCII). */ export declare const PUNCTUATION: string;
/** The string "\t\n\x0b\x0c\r ". */ export declare const WHITESPACE: string;
/** Combination of digits, letters, punctuation, and whitespace (ASCII). */ export declare const PRINTABLE: string;
/** Minimum unicode code point. */ export declare const MIN_CODE_POINT: number;
/** Maximum unicode code point. */ export declare const MAX_CODE_POINT: number;
/**
 * Get characters whose UTF-16 code units are given.
 * @param codes UTF-16 code units
 * @returns characters
 */ export declare function fromCharCode(...codes: number[]): string;
/**
 * Get characters whose unicode code points are given.
 * @param codes unicode code points
 * @returns characters
 */ export declare function fromCodePoint(...codes: number[]): string;
/**
 * Combine multiple values into a string.
 * @param values values
 * @returns combined string
 */ export declare function concat(...values: unknown[]): string;
/**
 * Repeat string given number of times.
 * @param x a string
 * @param times number of times
 * @returns repeated string
 */ export declare function repeat(x: string, times: number): string;
/**
 * Get primitive value of string object.
 * @param x a string object
 * @returns primitive value
 */ export declare function valueOf(x: string): string;
/**
 * Get length of string.
 * @param x a string
 * @returns length of string
 */ export declare function length(x: string): number;
export { length as size };
/**
 * Get character at given index in string.
 * @param x a string
 * @param at character index
 * @return character
 */ export declare function charAt(x: string, at: number): string;
/**
 * Get UTF-16 code unit of a character in string.
 * @param x a string
 * @param at character index
 * @returns UTF-16 code unit
 */ export declare function charCodeAt(x: string, at: number): number;
/**
 * Get unicode code point of a character in string.
 * @param x a string
 * @param at character index
 * @returns unicode code point
 */ export declare function codePointAt(x: string, at: number): number | undefined;
/**
 * Compare two strings in the current or given locale.
 * @param x a string
 * @param y another string
 * @param locales language or locale tag(s)
 * @param options comparison options
 * @returns x<y: -ve, x=y: 0, x>y: +ve
 * @example
 * ```javascript
 * xstring.localeCompare('abra', 'bulbasaur');
 * // → -1
 *
 * xstring.localeCompare('bulbasaur', 'bulbasaur');
 * // → 0
 *
 * xstring.localeCompare('charmeleon', 'bulbasaur');
 * // → 1
 * ```
 */ export declare function localeCompare(x: string, y: string, locales?: string | string[], options?: Intl.CollatorOptions): number;
/**
 * Check if string has a given infix.
 * @param x a string
 * @param infix infix to look for
 * @param start start index [0]
 * @returns has infix?
 */ export declare function includes(x: string, infix: string, start?: number): boolean;
/**
 * Check if string has a given prefix.
 * @param x a string
 * @param prefix prefix to look for
 * @param start start index [0]
 * @returns has prefix?
 */ export declare function startsWith(x: string, prefix: string, start?: number): boolean;
/**
 * Check if string has a given suffix.
 * @param x a string
 * @param suffix suffix to look for
 * @param end end index [end]
 * @returns has suffix?
 */ export declare function endsWith(x: string, suffix: string, end?: number): boolean;
/**
 * Get first index of a given infix in string.
 * @param x a string
 * @param infix infix to look for
 * @param start start index [0]
 * @returns first index of infix
 */ export declare function indexOf(x: string, infix: string, start?: number): number;
/**
 * Get last index of a given infix in string.
 * @param x a string
 * @param infix infix to look for
 * @param rstart reverse start index [end-1]
 * @returns last index of infix
 */ export declare function lastIndexOf(x: string, infix: string, rstart?: number): number;
/**
 * Get first index of regular expression match in string.
 * @param x a string
 * @param regexp regular expression
 * @returns first index of match
 */ export declare function search(x: string, regexp: string | RegExp): number;
/**
 * Get results of matching string with regular expression.
 * @param x a string
 * @param regexp regular expression
 * @returns /g: all matches, else: match with capturing groups or null
 */ export declare function match(x: string, regexp: string | RegExp): RegExpMatchArray | null;
/**
 * Get detailed results of matching string with regular expression.
 * @param x a string
 * @param regexp regular expression (with /g)
 * @returns match with capturing groups ...
 */ export declare function matchAll(x: string, regexp: RegExp): IterableIterator<RegExpMatchArray>;
/**
 * Get string representation of string.
 * @param x a string
 * @returns string representation
 */ export declare function toString(x: string): string;
/**
 * Extract section of string.
 * @param x a string
 * @param start start index (-ve ⇒ from right) [0]
 * @param end end index (-ve ⇒ from right) [end]
 * @returns section of string
 */ export declare function slice(x: string, start?: number, end?: number): string;
/**
 * Extract section of string.
 * @param x a string
 * @param start start index (-ve ⇒ 0) [0]
 * @param end end index (-ve ⇒ 0) [end]
 * @returns section of string
 */ export declare function substring(x: string, start: number, end?: number): string;
/**
 * Split string by a given separator into substrings.
 * @param x a string
 * @param separator separator string or regular expression
 * @param limit maximum number of substrings
 * @returns substrings
 */ export declare function split(x: string, separator?: string | RegExp, limit?: number): string[];
/**
 * Remove whitespace from begining of string.
 * @param x a string
 * @returns trimmed string
 */ export declare function trimStart(x: string): string;
/**
 * Remove whitespace from end of string.
 * @param x a string
 * @returns trimmed string
 */ export declare function trimEnd(x: string): string;
/**
 * Remove whitespace from begining and end of string.
 * @param x a string
 * @returns trimmed string
 */ export declare function trim(x: string): string;
/**
 * Pad start of string to fit a desired length.
 * @param x a string
 * @param length desired length
 * @param padding pad with [ ]
 * @returns padded string
 */ export declare function padStart(x: string, length: number, padding?: string): string;
/**
 * Pad end of string to fit a desired length.
 * @param x a string
 * @param length desired length
 * @param padding pad with [ ]
 * @returns padded string
 */ export declare function padEnd(x: string, length: number, padding?: string): string;
/**
 * Convert string to upper case.
 * @param x a string
 * @returns upper cased string
 */ export declare function toUpperCase(x: string): string;
/**
 * Convert string to upper case, as per locale-specific case mappings.
 * @param x a string
 * @param locales BCP 47 language tag(s)
 * @returns upper cased string
 */ export declare function toLocaleUpperCase(x: string, locales?: string | string[]): string;
/**
 * Convert string to lower case.
 * @param x a string
 * @returns lower cased string
 */ export declare function toLowerCase(x: string): string;
/**
 * Convert string to lower case, as per locale-specific case mappings.
 * @param x a string
 * @param locales BCP 47 language tag(s)
 * @returns lower cased string
 */ export declare function toLocaleLowerCase(x: string, locales?: string | string[]): string;
/** Handle replacement of matched string and parameters with another string. */ export type ReplaceFunction = (substring: string, ...args: unknown[]) => string;
/**
 * Replace first match of given pattern by replacement.
 * @param x a string
 * @param pattern substring to match
 * @param replacement replacement substring
 * @returns replaced string
 */ export declare function replace(x: string, pattern: string, replacement: string): string;
/**
 * Replace first or all matches of given pattern by replacement.
 * @param x a string
 * @param pattern pattern to match
 * @param replacement replacement substring or replacer
 * @returns replaced string
 */ export declare function replace(x: string, pattern: string | RegExp, replacement: string | ReplaceFunction): string;
/**
 * Normalize string by given form, as per Unicode Standard Annex #15.
 * @param x a string
 * @param form normalization form (NFC, NFD, NFKC, NFKD)
 * @returns normalized string
 */ export declare function normalize(x: string, form?: string): string;
/**
 * Create string from arguments, like `Array.of()`.
 * @param args arguments
 * @returns p + q + ... | [p, q, ...] = args
 * @example
 * ```javascript
 * xstring.of('a', 1);
 * // → 'a1'
 *
 * xstring.of(1, 2);
 * // → '12'
 *
 * xstring.of();
 * // → ''
 * ```
 */ export declare function of(...args: string[]): string;
/**
 * Handle transformation of a substring (or character) to another.
 * @param v a substring (or character)
 * @param i index of substring
 * @param x string containing the substring
 * @returns transformed substring
 */ export type MapFunction = (v: string, i: number, x?: string) => string;
/**
 * Create string from iterable, like `Array.from()`.
 * @param xs list of strings (iterable)
 * @param fm map function (x, i)
 * @param ths this argument
 * @returns p + q + ... | [p, q, ...] = xs
 * @example
 * ```javascript
 * xstring.from(['a', 'b']);
 * // → 'ab'
 *
 * xstring.from('abc', (v) => String.fromCharCode(v.charCodeAt()+1));
 * // → 'bcd'
 *
 * xstring.from(new Set().add('a').add('b'));
 * // → 'ab'
 *
 * xstring.from(new Map().set('a', 1).set('b', 2));
 * // → 'a,1b,2'
 * ```
 */ export declare function from(xs: Iterable<string>, fm?: MapFunction, ths?: unknown): string;
/**
 * Remove/replace characters in a string.
 * @param x a string
 * @param start start index
 * @param remove number of characters to remove
 * @param add substring to add
 * @returns x[0:i] + add + x[i+r] | i = start, r = remove
 */ export declare function splice(x: string, start: number, remove?: number, add?: string): string;
/**
 * Reverse a string.
 * @param x a string
 * @returns reversed string
 */ export declare function reverse(x: string): string;
/**
 * Handle comparison of two strings.
 * @param a a string
 * @param b another string
 * @returns x<y: -ve, x=y: 0, x>y: +ve
 */ export type CompareFunction = (a: string, b: string) => number;
/**
 * Arrange characters in an order.
 * @param x a string
 * @param fc compare function (a, b)
 */ export declare function sort(x: string, fc?: CompareFunction): string;
/**
 * Handle selection of a substring (or character) in string.
 * @param v a substring (or character)
 * @param i index of substring in string
 * @param x string containing the substring
 * @returns whether it is selected
 */ export type TestFunction = (v: string, i: number, x: string) => boolean;
/**
 * Filter characters which pass a test.
 * @param x a string
 * @param ft test function (v, i, x)
 * @param ths this argument
 * @returns characters which pass the test
 * @example
 * ```javascript
 * xstring.filter('g00df00d', (v) => v<='f');
 * // → '00df00d'
 *
 * xstring.filter('badfood', (v) => v<='f');
 * // → 'badfd'
 *
 * xstring.filter('', (v) => v<='f');
 * // → ''
 * ```
 */ export declare function filter(x: string, ft: TestFunction, ths?: unknown): string;
/**
 * Get a string of spaces.
 * @param n number of spaces
 * @returns string of spaces
 * @example
 * ```javascript
 * xstring.spaces(4);
 * // → '    '
 *
 * xstring.spaces(6);
 * // → '      '
 *
 * xstring.spaces(0);
 * // → ''
 *
 * xstring.spaces(-1);
 * // → ''
 * ```
 */ export declare function spaces(n: number): string;
/**
 * Check if value is a string.
 * @param v a value
 * @returns whether value is a string
 * @example
 * ```javascript
 * xstring.is('panini');
 * // → true
 *
 * xstring.is("valmiki");
 * // → true
 *
 * xstring.is(String('vyasa'));
 * // → true
 *
 * xstring.is({shakespeare: 'literature'});
 * // → false
 *
 * xstring.is(71811313518);
 * // → false (what's this?)
 *
 * xstring.is();
 * // → false
 * ```
 */ export declare function is(v: unknown): boolean;
/**
 * Check if string is empty.
 * @param x a string
 * @returns whether string is empty
 */ export declare function isEmpty(x: string): boolean;
/**
 * Check if string is a character.
 * @param x a string
 * @returns whether string is a character
 */ export declare function isCharacter(x: string): boolean;
/**
 * Get non-negative index within string.
 * @param x a string
 * @param at character index
 * @returns +ve index
 */ export declare function index(x: string, at: number): number;
/**
 * Get non-negative index range within string.
 * @param x a string
 * @param start start index
 * @param end end index
 * @returns +ve index range [start, end]
 */ export declare function indexRange(x: string, start: number, end: number): [number, number];
/**
 * Get unicode code point range of string.
 * @param x a string
 * @returns code point range [min, max]
 */ export declare function codePointRange(x: string): [number, number];
/**
 * Compare two strings.
 * @param x a string
 * @param y another string
 * @returns x<y: -ve, x=y: 0, x>y: +ve
 */ export declare function compare(x: string, y: string): number;
/**
 * Check if two strings are equal.
 * @param x a string
 * @param y another string
 * @returns x=y?
 */ export declare function isEqual(x: string, y: string): boolean;
export { startsWith as isPrefix };
export { endsWith as isSuffix };
export { includes as isInfix };
/**
 * Get character at a given index in string.
 * @param x a string
 * @param at character index (-ve ⇒ from right)
 * @returns x[i] | i = at
 */ export declare function get(x: string, at: number): string;
export { get as at };
/**
 * Get characters at indices.
 * @param x a string
 * @param ats character indices (-ve ⇒ from right)
 * @returns x[i] + x[j] + ... | [i, j, ...] = ats
 */ export declare function getAll(x: string, ats: Iterable<number>): string;
/**
 * Write a substring at specified index in string.
 * @param x a string
 * @param at write index (-ve ⇒ from right)
 * @param write substring to write
 * @returns x[0:i] + w + x[i+|w|:] | i = at, w = write
 */ export declare function set(x: string, at: number, write: string): string;
/**
 * Get leftmost part of string.
 * @param x a string
 * @param count number of characters [1]
 * @returns x[0:n] | n = count
 * @example
 * ```javascript
 * xstring.begin('Thai Sweet Chilli Sauce', 4);
 * // → 'Thai'
 *
 * xstring.begin('Thai Sweet Chilli Sauce', 10);
 * // → 'Thai Sweet'
 *
 * xstring.begin('Thai Sweet Chilli Sauce', 80);
 * // → 'Thai Sweet Chilli Sauce'
 *
 * xstring.begin('Thai Sweet Chilli Sauce', -1);
 * // → ''
 * ```
 */ export declare function begin(x: string, count?: number): string;
export { begin as prefix };
export { begin as left };
/**
 * Get a portion of string from middle.
 * @param x a string
 * @param start start index
 * @param count number of characters [1]
 * @returns x[i:i+n] | i = start, n = count
 * @example
 * ```javascript
 * xstring.mid('Thai Sweet Chilli Sauce', 5, 5);
 * // → 'Sweet'
 *
 * xstring.mid('Thai Sweet Chilli Sauce', 5, 12);
 * // → 'Sweet Chilli'
 *
 * xstring.mid('Thai Sweet Chilli Sauce', 5);
 * // → 'Sweet Chilli Sauce'
 *
 * xstring.mid('Thai Sweet Chilli Sauce', 5, -1);
 * // → ''
 *
 * xstring.mid('Thai Sweet Chilli Sauce', -5);
 * // → 'Sauce'
 * ```
 */ export declare function middle(x: string, start: number, count?: number): string;
export { middle as infix };
/**
 * Get rightmost part of string.
 * @param x a string
 * @param count number of characters [1]
 * @returns x[|x|-n:] | n = count
 * @example
 * ```javascript
 * xstring.end('Thai Sweet Chilli Sauce', 5);
 * // → 'Sauce'
 *
 * xstring.end('Thai Sweet Chilli Sauce', 12);
 * // → 'Chilli Sauce'
 *
 * xstring.end('Thai Sweet Chilli Sauce', 80);
 * // → 'Thai Sweet Chilli Sauce'
 *
 * xstring.end('Thai Sweet Chilli Sauce', -1);
 * // → ''
 * ```
 */ export declare function end(x: string, count?: number): string;
export { end as suffix };
export { end as right };
/**
 * Get the longest common infix between strings.
 * @param x a string
 * @param y another string
 * @returns longest common infix
 * @example
 * ```javascript
 * xstring.longestCommonInfix('mangala', 'mangalyaan');
 * // → 'mangal'
 *
 * xstring.longestCommonInfix('easter', 'tertiary');
 * // → 'ter'
 *
 * xstring.longestCommonInfix('dismiss', 'mississipi');
 * // → 'miss'
 * ```
 */ export declare function longestCommonInfix(x: string, y: string): string;
/**
 * Get the longest common prefix of strings.
 * @param x a string
 * @param y another string
 * @returns longest common prefix
 * @example
 * ```javascript
 * xstring.longestCommonPrefix('peacock', 'peahen');
 * // → 'pea'
 *
 * xstring.longestCommonPrefix('inception', 'interstellar');
 * // → 'in'
 *
 * xstring.longestCommonPrefix('mars', 'tars');
 * // → ''
 * ```
 */ export declare function longestCommonPrefix(x: string, y: string): string;
/**
 * Get the longest common suffix of strings.
 * @param x a string
 * @param y another string
 * @returns longest common suffix
 * @example
 * ```javascript
 * xstring.longestCommonSuffix('peacock', 'hancock');
 * // → 'cock'
 *
 * xstring.longestCommonSuffix('mars', 'tars');
 * // → 'ars'
 *
 * xstring.longestCommonSuffix('chief', 'master');
 * // → ''
 * ```
 */ export declare function longestCommonSuffix(x: string, y: string): string;
/**
 * Get the longest uncommon infixes of strings.
 * @param x a string
 * @param y another string
 * @returns [infix1, infix2]
 * @example
 * ```javascript
 * xstring.longestUncommonInfixes('rollcage', 'ridecage');
 * // → ['oll', 'ide']
 *
 * xstring.longestUncommonInfixes('riverbed', 'roverbed');
 * // → ['i', 'o']
 *
 * xstring.longestUncommonInfixes('chocolatier', 'engineer');
 * // → ['chocolati', 'engine']
 * ```
 */ export declare function longestUncommonInfixes(x: string, y: string): [string, string];
/**
 * Convert a string to baseline characters (limited support).
 * @param x a string
 * @param fsup map function for superscript characters (v, i, x)
 * @param fsub map function for subscript characters (v, i, x)
 * @returns baselined string
 * @example
 * ```javascript
 * xstring.toBaseline('ax²+bx+c');
 * // → 'ax2+bx+c'
 *
 * xstring.toBaseline('H₂SO₄ beaker');
 * // → 'H2SO4 beaker'
 *
 * xstring.toBaseline('6.626 x 10⁻³⁴', ['^']);
 * // → '6.626 x 10^-34'
 *
 * xstring.toBaseline('1010₂', null, [' (base-', ')']);
 * // → '1010 (base-2)'
 * ```
 */ export declare function toBaseline(x: string, fsup?: MapFunction | null, fsub?: MapFunction | null): string;
/**
 * Convert a string to superscript characters (limited support).
 * @param x a string
 * @returns superscripted characters
 * @example
 * ```javascript
 * xstring.toSuperscript('hello world');
 * // → 'ʰᵉˡˡᵒ ʷᵒʳˡᵈ'
 *
 * xstring.toSuperscript('DECCAN PLATEAU');
 * // → 'ᴰᴱCCᴬᴺ ᴾᴸᴬᵀᴱᴬᵁ'
 *
 * '6.626 x 10' + xstring.toSuperscript('-34');
 * // → '6.626 x 10⁻³⁴' (Planck's constant)
 * ```
 */ export declare function toSuperscript(x: string): string;
/**
 * Convert a string to superscript characters (limited support).
 * @param x a string
 * @returns superscripted characters
 * @example
 * ```javascript
 * xstring.toSubscript('hello world');
 * // → 'ₕₑₗₗₒ wₒᵣₗd'
 *
 * xstring.toSubscript('DECCAN PLATEAU');
 * // → 'DECCAN PLATEAU'
 *
 * 'KNO' + xstring.toSubscript('3');
 * // → 'KNO₃' (Potassium Nitrate)
 * ```
 */ export declare function toSubscript(x: string): string;
/**
 * Split a string into words, after de-casing it.
 * @param x a string
 * @param re word seperator pattern [/[^0-9A-Za-z]+/g]
 * @returns words in the string
 * @example
 * ```javascript
 * xstring.toWords('Malwa Plateau');
 * // → ['Malwa', 'Plateau']
 *
 * xstring.toWords('::chota::nagpur::');
 * // → ['chota', 'nagpur']
 *
 * xstring.toWords('deccan___plateau');
 * // → ['deccan', 'plateau']
 *
 * xstring.toWords('westernGhats');
 * // → ['western', 'Ghats']
 *
 * xstring.toWords('parseURLToJSON');
 * // → ['parse', 'URL', 'To', 'JSON']
 */ export declare function toWords(x: string, re?: RegExp | null): string[];
/**
 * Convert a string to title-case.
 * @param x a string
 * @param re word seperator pattern [/[^0-9A-Za-z]+/g]
 * @returns Title Case
 * @example
 * ```javascript
 * xstring.toTitleCase('Geminid meteor shower');
 * // → 'Geminid Meteor Shower'
 *
 * xstring.toTitleCase('deccan___plateau');
 * // → 'Deccan Plateau'
 *
 * xstring.toTitleCase('parseURLToJSON', null, '_');
 * // → 'Parse_URL_To_JSON'
 * ```
 */ export declare function toTitleCase(x: string, re?: RegExp | null, sep?: string): string;
/**
 * Convert a string to kebab-case.
 * @param x a string
 * @param re word seperator pattern [/[^0-9A-Za-z]+/g]
 * @param sep separator to join with [-]
 * @returns kebab-case | kebab<join>case
 */ export declare function toKebabCase(x: string, re?: RegExp | null, sep?: string): string;
/**
 * Convert a string to snake-case.
 * @param x a string
 * @param re word seperator pattern [/[^0-9A-Za-z]+/g]
 * @returns snake_case
 * @example
 * ```javascript
 * xstring.toSnakeCase('Malwa Plateau');
 * // → 'malwa_plateau'
 *
 * xstring.toSnakeCase('::chota::nagpur::', '-');
 * // → 'chota-nagpur'
 *
 * xstring.toSnakeCase('deccan___plateau', '.', '_');
 * // → 'deccan.plateau'
 * ```
 */ export declare function toSnakeCase(x: string, re?: RegExp | null): string;
/**
 * Convert a string to camel-case.
 * @param x a string
 * @param re word seperator pattern [/[^0-9A-Za-z]+/g]
 * @param upper upper camel case?
 * @returns camelCase | CamelCase
 * @example
 * ```javascript
 * xstring.toCamelCase('Western Ghats');
 * // → 'westernGhats'
 *
 * xstring.toCamelCase('cardamom--hills', 1);
 * // → 'CardamomHills'
 *
 * xstring.toCamelCase('EAstErn__ghAts', 1, '_');
 * // → 'EasternGhats'
 * ```
 */ export declare function toCamelCase(x: string, re?: RegExp | null, upper?: boolean): string;
/**
 * Convert a string to pascal-case.
 * @param x a string
 * @param re word seperator pattern [/[^0-9A-Za-z]+/g]
 * @returns PascalCase
 */ export declare function toPascalCase(x: string, re?: RegExp | null): string;
/**
 * Convert a string to slug-case (URL-friendly kebab-case).
 * @param x a string
 * @param re word separator pattern [/[^0-9A-Za-z]+/g]
 * @param sep separator to join with [-]
 * @returns slug-case | slug<join>case
 */ export declare function toSlugCase(x: string, re?: RegExp | null, sep?: string): string;
export { toSlugCase as slugify };
/**
 * Get characters that cycle through string.
 * @param x a string
 * @param start start index
 * @param count number of characters [length]
 */ export declare function cycle(x: string, start: number, count?: number): string;
/**
 * Rotate characters in string.
 * @param x a string
 * @param n rotate amount (+ve: left, -ve: right)
 */ export declare function rotate(x: string, n: number): string;
/**
 * Breaks string at given indices.
 * @param x a string
 * @param is split indices (sorted)
 */ /**
 * Breaks string after given indices.
 * @param x a string
 * @param is split indices (sorted)
 */ /**
 * Gives characters present in any string.
 * @param x a string
 * @param y another string
 * @param fc compare function (a, b)
 * @param fm map function (v, i, x)
 */ /**
 * Get n-grams of a string.
 * @param x a string
 * @param n n-gram length
 * @returns [x[0:n], x[1:n+1], ...]
 * @example
 * ```javascript
 * xstring.ngrams('card', 2);
 * // → ['ca', 'ar', 'rd']
 *
 * xstring.ngrams('triple-h', 3);
 * // → ['tri', 'rip', 'ipl', 'ple', 'le-', 'e-h']
 *
 * xstring.ngrams('brocklesner', 10);
 * // → ['brocklesne', 'rocklesner']
 * ```
 */ export declare function ngrams(x: string, n: number): string[];
/**
 * Find unique n-grams of a string.
 * @param x a string
 * @param n n-gram length
 * @returns Set \{gᵢ\} | gᵢ = iᵗʰ n-gram
 */ export declare function uniqueNgrams(x: string, n: number): Set<string>;
/**
 * Count the total number of n-grams of a string.
 * @param x a string
 * @param n n-gram length
 * @returns |gᵢ| | gᵢ = iᵗʰ n-gram
 */ export declare function countNgrams(x: string, n: number): number;
/**
 * Count the total number of unique n-grams of a string.
 * @param x a string
 * @param n n-gram length
 * @returns |Set \{gᵢ\}| | gᵢ = iᵗʰ n-gram
 */ export declare function countUniqueNgrams(x: string, n: number): number;
/**
 * Count each n-gram of a string.
 * @param x a string
 * @param n n-gram length
 * @returns Map \{gᵢ: count(gᵢ)\} | gᵢ = iᵗʰ n-gram
 */ export declare function countEachNgram(x: string, n: number): Map<string, number>;
/**
 * Get matching n-grams between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns [gᵢ] | gᵢ = iᵗʰ matching n-gram
 * @example
 * ```javascript
 * xstring.matchingNgrams('worm', 'storm', 2);
 * // → ['or', 'rm']
 *
 * xstring.matchingNgrams('astronaut', 'astronomer', 3);
 * // → ['ast', 'str', 'tro', 'ron']
 *
 * xstring.matchingNgrams('coconut', 'cotton', 2);
 * // → ['co', 'on']
 * ```
 */ export declare function matchingNgrams(x: string, y: string, n: number): string[];
/**
 * Get unique matching n-grams between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns Set \{gᵢ\} | gᵢ = iᵗʰ unique matching n-gram
 */ export declare function uniqueMatchingNgrams(x: string, y: string, n: number): Set<string>;
/**
 * Count the total number of matching n-grams between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns |[gᵢ]| | gᵢ = iᵗʰ matching n-gram
 * @example
 * ```javascript
 * xstring.countMatchingNgrams('worm', 'storm', 2);
 * // → 2 ('or', 'rm')
 *
 * xstring.countMatchingNgrams('astronaut', 'astronomer', 3);
 * // → 4 ('ast', 'str', 'tro', 'ron')
 *
 * xstring.countMatchingNgrams('coconut', 'cotton', 2);
 * // → 2 ('co', 'on')
 * ```
 */ export declare function countMatchingNgrams(x: string, y: string, n: number): number;
/**
 * Count each matching n-gram between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns Map \{gᵢ: count(gᵢ)\} | gᵢ = iᵗʰ matching n-gram
 */ export declare function countEachMatchingNgram(x: string, y: string, n: number): Map<string, number>;
/**
 * Count the total number of unique matching n-grams between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns |Set \{gᵢ\}| | gᵢ = iᵗʰ unique matching n-gram
 */ export declare function countUniqueMatchingNgrams(x: string, y: string, n: number): number;
/**
 * Get euclidean distance between strings.
 * @param x a string
 * @param y another string
 * @returns euclidean distance
 * @example
 * ```javascript
 * xstring.euclideanDistance('a', 'b');
 * // → 1
 *
 * xstring.euclideanDistance('logo', 'pogo');
 * // → 4
 *
 * xstring.euclideanDistance('doctor', 'broker');
 * // → 18.384776310850235
 * ```
 */ export declare function euclideanDistance(x: string, y: string): number;
/**
 * Get hamming distance between strings.
 * @param x a string
 * @param y another string
 * @returns hamming distance
 * @example
 * ```javascript
 * xstring.hammingDistance('rowan', 'raven');
 * // → 3
 *
 * xstring.hammingDistance('atkinson', 'atkinson');
 * // → 0
 *
 * xstring.hammingDistance('bean', 'green');
 * // → NaN (strings are of different length)
 * ```
 */ export declare function hammingDistance(x: string, y: string): number;
/**
 * Get jaccard index between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns |X ∩ Y|/|X ∪ Y| | X,Y = n-grams of x,y
 * @example
 * ```javascript
 * xstring.jaccardIndex('pocket', 'pocket');
 * // → 1
 *
 * xstring.jaccardIndex('monster', 'rocket');
 * // → 0
 *
 * xstring.jaccardIndex('pikachu', 'raichu', 3);
 * // → 0.125
 * ```
 */ export declare function jaccardIndex(x: string, y: string, n: number): number;
/**
 * Get jaccard distance between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns 1 - jaccardIndex(x, y)
 * @example
 * ```javascript
 * xstring.jaccardDistance('pocket', 'pocket');
 * // → 0
 *
 * xstring.jaccardDistance('monster', 'rocket');
 * // → 1
 *
 * xstring.jaccardDistance('pikachu', 'raichu', 3);
 * // → 0.875
 * ```
 */ export declare function jaccardDistance(x: string, y: string, n: number): number;
/**
 * Get Sørensen-Dice index between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns 2|X ∩ Y|/(|X| + |Y|) | X,Y = n-grams of x,y
 * @example
 * ```javascript
 * xstring.sorensenDiceIndex('pocket', 'pocket');
 * // → 1
 *
 * xstring.sorensenDiceIndex('monster', 'rocket');
 * // → 0
 *
 * xstring.sorensenDiceIndex('pikachu', 'raichu', 3);
 * // → 0.2222222222222222
 * ```
 */ export declare function sorensenDiceIndex(x: string, y: string, n: number): number;
/**
 * Get Sørensen-Dice distance between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @returns 1 - sorensenDiceIndex(x, y)
 * @example
 * ```javascript
 * xstring.sorensenDiceDistance('pocket', 'pocket');
 * // → 0
 *
 * xstring.sorensenDiceDistance('monster', 'rocket');
 * // → 1
 *
 * xstring.sorensenDiceDistance('pikachu', 'raichu', 3);
 * // → 0.7777777777777778
 * ```
 */ export declare function sorensenDiceDistance(x: string, y: string, n: number): number;
/**
 * Get Tversky index between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @param a alpha [1]
 * @param b beta [1]
 * @returns |X ∩ Y|/(|X ∩ Y| + α|X \ Y| + β|Y \ X|) | X,Y = n-grams of x,y
 * @example
 * ```javascript
 * xstring.tverskyIndex('pocket', 'pocket');
 * // → 1
 *
 * xstring.tverskyIndex('monster', 'rocket');
 * // → 0
 *
 * xstring.tverskyIndex('pikachu', 'raichu', 0.2, 0.4, 3);
 * // → 0.3333333333333333
 * ```
 */ export declare function tverskyIndex(x: string, y: string, n: number, a?: number, b?: number): number;
/**
 * Get Tversky distance between strings.
 * @param x a string
 * @param y another string
 * @param n n-gram length
 * @param a alpha [1]
 * @param b beta [1]
 * @returns 1 - tverskyIndex(x, y)
 * @example
 * ```javascript
 * xstring.tverskyDistance('pocket', 'pocket');
 * // → 0
 *
 * xstring.tverskyDistance('monster', 'rocket');
 * // → 1
 *
 * xstring.tverskyDistance('pikachu', 'raichu', 0.2, 0.4, 3);
 * // → 0.6666666666666667
 * ```
 */ export declare function tverskyDistance(x: string, y: string, n: number, a?: number, b?: number): number;
/**
 * Get Jaro similarity between strings.
 * @param x a string
 * @param y another string
 * @returns (m/|x| + m/|y| + (m-t)/m)/3 | m = # matches, t = # transpositions
 * @example
 * ```javascript
 * xstring.jaroSimilarity('no', 'match');
 * // → 0
 *
 * xstring.jaroSimilarity('teapot', 'teapot');
 * // → 1
 *
 * xstring.jaroSimilarity('jellyfish', 'smellyfish');
 * // → 0.8962962962962964
 * ```
 */ export declare function jaroSimilarity(x: string, y: string): number;
/**
 * Get Jaro distance between strings.
 * @param x a string
 * @param y another string
 * @returns 1 - jaroSimilarity(x, y)
 * @example
 * ```javascript
 * xstring.jaroDistance('no', 'match');
 * // → 1
 *
 * xstring.jaroDistance('teapot', 'teapot');
 * // → 0
 *
 * xstring.jaroDistance('jellyfish', 'smellyfish');
 * // → 0.10370370370370363
 * ```
 */ export declare function jaroDistance(x: string, y: string): number;
/**
 * Get Jaro-Winkler similarity between strings.
 * @param x a string
 * @param y another string
 * @param p scaling factor for common prefix (0.1 - 0.25) [0.1]
 * @returns simⱼ + ℓp(1 - simⱼ) | simⱼ = jaro similarity, ℓ = |longest common prefix|
 * @example
 * ```javascript
 * xstring.jaroWinklerSimilarity('no', 'match');
 * // → 0
 *
 * xstring.jaroWinklerSimilarity('teapot', 'teapot');
 * // → 1
 *
 * xstring.jaroWinklerSimilarity('jelly', 'jellyfish');
 * // → 0.9111111111111111
 * ```
 */ export declare function jaroWinklerSimilarity(x: string, y: string, p?: number): number;
/**
 * Get Jaro-Winkler distance between strings.
 * @param x a string
 * @param y another string
 * @param p scaling factor for common prefix (0.1 - 0.25) [0.1]
 * @returns 1 - jaroWinklerSimilarity(x, y)
 * @example
 * ```javascript
 * xstring.jaroWinklerDistance('no', 'match');
 * // → 1
 *
 * xstring.jaroWinklerDistance('teapot', 'teapot');
 * // → 0
 *
 * xstring.jaroWinklerDistance('jelly', 'jellyfish');
 * // → 0.0888888888888889
 * ```
 */ export declare function jaroWinklerDistance(x: string, y: string, p?: number): number;
/**
 * Get Levenshtein distance between strings.
 * @param x a string
 * @param y another string
 * @param ins insertion cost [1]
 * @param del deletion cost [1]
 * @param sub substitution cost [1]
 * @returns levenshtein distance
 * @example
 * ```javascript
 * xstring.levenshteinDistance('hareram', 'hareram');
 * // → 0
 *
 * xstring.levenshteinDistance('church', 'torch');
 * // → 3
 *
 * xstring.levenshteinDistance('mr. bean', 'ben 10', 1, 0.1, 1);
 * // → 3.5
 * ```
 */ export declare function levenshteinDistance(x: string, y: string, ins?: number, del?: number, sub?: number): number;
/**
 * Get Damerau–Levenshtein distance between strings.
 * @param x a string
 * @param y another string
 * @param ins insertion cost [1]
 * @param del deletion cost [1]
 * @param sub substitution cost [1]
 * @param tra transposition cost [1]
 * @returns damerau–levenshtein distance
 * @example
 * ```javascript
 * xstring.damerauLevenshteinDistance('gnu', 'gun');
 * // → 1
 *
 * xstring.damerauLevenshteinDistance('software', 'softwear');
 * // → 2
 *
 * xstring.damerauLevenshteinDistance('level field', 'lvele feidl', 1, 1, 1, 0.1);
 * // → 0.4
 * ```
 */ export declare function damerauLevenshteinDistance(x: string, y: string, ins?: number, del?: number, sub?: number, tra?: number): number;