twitst4tz

punycode.es6.js (12630B)

---

 'use strict';
 
 /** Highest positive signed 32-bit float value */
 const maxInt = 2147483647; // aka. 0x7FFFFFFF or 2^31-1
 
 /** Bootstring parameters */
 const base = 36;
 const tMin = 1;
 const tMax = 26;
 const skew = 38;
 const damp = 700;
 const initialBias = 72;
 const initialN = 128; // 0x80
 const delimiter = '-'; // '\x2D'
 
 /** Regular expressions */
 const regexPunycode = /^xn--/;
 const regexNonASCII = /[^\0-\x7E]/; // non-ASCII chars
 const regexSeparators = /[\x2E\u3002\uFF0E\uFF61]/g; // RFC 3490 separators
 
 /** Error messages */
 const errors = {
 	'overflow': 'Overflow: input needs wider integers to process',
 	'not-basic': 'Illegal input >= 0x80 (not a basic code point)',
 	'invalid-input': 'Invalid input'
 };
 
 /** Convenience shortcuts */
 const baseMinusTMin = base - tMin;
 const floor = Math.floor;
 const stringFromCharCode = String.fromCharCode;
 
 /*--------------------------------------------------------------------------*/
 
 /**
  * A generic error utility function.
  * @private
  * @param {String} type The error type.
  * @returns {Error} Throws a `RangeError` with the applicable error message.
  */
 function error(type) {
 	throw new RangeError(errors[type]);
 }
 
 /**
  * A generic `Array#map` utility function.
  * @private
  * @param {Array} array The array to iterate over.
  * @param {Function} callback The function that gets called for every array
  * item.
  * @returns {Array} A new array of values returned by the callback function.
  */
 function map(array, fn) {
 	const result = [];
 	let length = array.length;
 	while (length--) {
 		result[length] = fn(array[length]);
 	}
 	return result;
 }
 
 /**
  * A simple `Array#map`-like wrapper to work with domain name strings or email
  * addresses.
  * @private
  * @param {String} domain The domain name or email address.
  * @param {Function} callback The function that gets called for every
  * character.
  * @returns {Array} A new string of characters returned by the callback
  * function.
  */
 function mapDomain(string, fn) {
 	const parts = string.split('@');
 	let result = '';
 	if (parts.length > 1) {
 		// In email addresses, only the domain name should be punycoded. Leave
 		// the local part (i.e. everything up to `@`) intact.
 		result = parts[0] + '@';
 		string = parts[1];
 	}
 	// Avoid `split(regex)` for IE8 compatibility. See #17.
 	string = string.replace(regexSeparators, '\x2E');
 	const labels = string.split('.');
 	const encoded = map(labels, fn).join('.');
 	return result + encoded;
 }
 
 /**
  * Creates an array containing the numeric code points of each Unicode
  * character in the string. While JavaScript uses UCS-2 internally,
  * this function will convert a pair of surrogate halves (each of which
  * UCS-2 exposes as separate characters) into a single code point,
  * matching UTF-16.
  * @see `punycode.ucs2.encode`
  * @see <https://mathiasbynens.be/notes/javascript-encoding>
  * @memberOf punycode.ucs2
  * @name decode
  * @param {String} string The Unicode input string (UCS-2).
  * @returns {Array} The new array of code points.
  */
 function ucs2decode(string) {
 	const output = [];
 	let counter = 0;
 	const length = string.length;
 	while (counter < length) {
 		const value = string.charCodeAt(counter++);
 		if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
 			// It's a high surrogate, and there is a next character.
 			const extra = string.charCodeAt(counter++);
 			if ((extra & 0xFC00) == 0xDC00) { // Low surrogate.
 				output.push(((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000);
 			} else {
 				// It's an unmatched surrogate; only append this code unit, in case the
 				// next code unit is the high surrogate of a surrogate pair.
 				output.push(value);
 				counter--;
 			}
 		} else {
 			output.push(value);
 		}
 	}
 	return output;
 }
 
 /**
  * Creates a string based on an array of numeric code points.
  * @see `punycode.ucs2.decode`
  * @memberOf punycode.ucs2
  * @name encode
  * @param {Array} codePoints The array of numeric code points.
  * @returns {String} The new Unicode string (UCS-2).
  */
 const ucs2encode = array => String.fromCodePoint(...array);
 
 /**
  * Converts a basic code point into a digit/integer.
  * @see `digitToBasic()`
  * @private
  * @param {Number} codePoint The basic numeric code point value.
  * @returns {Number} The numeric value of a basic code point (for use in
  * representing integers) in the range `0` to `base - 1`, or `base` if
  * the code point does not represent a value.
  */
 const basicToDigit = function(codePoint) {
 	if (codePoint - 0x30 < 0x0A) {
 		return codePoint - 0x16;
 	}
 	if (codePoint - 0x41 < 0x1A) {
 		return codePoint - 0x41;
 	}
 	if (codePoint - 0x61 < 0x1A) {
 		return codePoint - 0x61;
 	}
 	return base;
 };
 
 /**
  * Converts a digit/integer into a basic code point.
  * @see `basicToDigit()`
  * @private
  * @param {Number} digit The numeric value of a basic code point.
  * @returns {Number} The basic code point whose value (when used for
  * representing integers) is `digit`, which needs to be in the range
  * `0` to `base - 1`. If `flag` is non-zero, the uppercase form is
  * used; else, the lowercase form is used. The behavior is undefined
  * if `flag` is non-zero and `digit` has no uppercase form.
  */
 const digitToBasic = function(digit, flag) {
 	//  0..25 map to ASCII a..z or A..Z
 	// 26..35 map to ASCII 0..9
 	return digit + 22 + 75 * (digit < 26) - ((flag != 0) << 5);
 };
 
 /**
  * Bias adaptation function as per section 3.4 of RFC 3492.
  * https://tools.ietf.org/html/rfc3492#section-3.4
  * @private
  */
 const adapt = function(delta, numPoints, firstTime) {
 	let k = 0;
 	delta = firstTime ? floor(delta / damp) : delta >> 1;
 	delta += floor(delta / numPoints);
 	for (/* no initialization */; delta > baseMinusTMin * tMax >> 1; k += base) {
 		delta = floor(delta / baseMinusTMin);
 	}
 	return floor(k + (baseMinusTMin + 1) * delta / (delta + skew));
 };
 
 /**
  * Converts a Punycode string of ASCII-only symbols to a string of Unicode
  * symbols.
  * @memberOf punycode
  * @param {String} input The Punycode string of ASCII-only symbols.
  * @returns {String} The resulting string of Unicode symbols.
  */
 const decode = function(input) {
 	// Don't use UCS-2.
 	const output = [];
 	const inputLength = input.length;
 	let i = 0;
 	let n = initialN;
 	let bias = initialBias;
 
 	// Handle the basic code points: let `basic` be the number of input code
 	// points before the last delimiter, or `0` if there is none, then copy
 	// the first basic code points to the output.
 
 	let basic = input.lastIndexOf(delimiter);
 	if (basic < 0) {
 		basic = 0;
 	}
 
 	for (let j = 0; j < basic; ++j) {
 		// if it's not a basic code point
 		if (input.charCodeAt(j) >= 0x80) {
 			error('not-basic');
 		}
 		output.push(input.charCodeAt(j));
 	}
 
 	// Main decoding loop: start just after the last delimiter if any basic code
 	// points were copied; start at the beginning otherwise.
 
 	for (let index = basic > 0 ? basic + 1 : 0; index < inputLength; /* no final expression */) {
 
 		// `index` is the index of the next character to be consumed.
 		// Decode a generalized variable-length integer into `delta`,
 		// which gets added to `i`. The overflow checking is easier
 		// if we increase `i` as we go, then subtract off its starting
 		// value at the end to obtain `delta`.
 		let oldi = i;
 		for (let w = 1, k = base; /* no condition */; k += base) {
 
 			if (index >= inputLength) {
 				error('invalid-input');
 			}
 
 			const digit = basicToDigit(input.charCodeAt(index++));
 
 			if (digit >= base || digit > floor((maxInt - i) / w)) {
 				error('overflow');
 			}
 
 			i += digit * w;
 			const t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
 
 			if (digit < t) {
 				break;
 			}
 
 			const baseMinusT = base - t;
 			if (w > floor(maxInt / baseMinusT)) {
 				error('overflow');
 			}
 
 			w *= baseMinusT;
 
 		}
 
 		const out = output.length + 1;
 		bias = adapt(i - oldi, out, oldi == 0);
 
 		// `i` was supposed to wrap around from `out` to `0`,
 		// incrementing `n` each time, so we'll fix that now:
 		if (floor(i / out) > maxInt - n) {
 			error('overflow');
 		}
 
 		n += floor(i / out);
 		i %= out;
 
 		// Insert `n` at position `i` of the output.
 		output.splice(i++, 0, n);
 
 	}
 
 	return String.fromCodePoint(...output);
 };
 
 /**
  * Converts a string of Unicode symbols (e.g. a domain name label) to a
  * Punycode string of ASCII-only symbols.
  * @memberOf punycode
  * @param {String} input The string of Unicode symbols.
  * @returns {String} The resulting Punycode string of ASCII-only symbols.
  */
 const encode = function(input) {
 	const output = [];
 
 	// Convert the input in UCS-2 to an array of Unicode code points.
 	input = ucs2decode(input);
 
 	// Cache the length.
 	let inputLength = input.length;
 
 	// Initialize the state.
 	let n = initialN;
 	let delta = 0;
 	let bias = initialBias;
 
 	// Handle the basic code points.
 	for (const currentValue of input) {
 		if (currentValue < 0x80) {
 			output.push(stringFromCharCode(currentValue));
 		}
 	}
 
 	let basicLength = output.length;
 	let handledCPCount = basicLength;
 
 	// `handledCPCount` is the number of code points that have been handled;
 	// `basicLength` is the number of basic code points.
 
 	// Finish the basic string with a delimiter unless it's empty.
 	if (basicLength) {
 		output.push(delimiter);
 	}
 
 	// Main encoding loop:
 	while (handledCPCount < inputLength) {
 
 		// All non-basic code points < n have been handled already. Find the next
 		// larger one:
 		let m = maxInt;
 		for (const currentValue of input) {
 			if (currentValue >= n && currentValue < m) {
 				m = currentValue;
 			}
 		}
 
 		// Increase `delta` enough to advance the decoder's <n,i> state to <m,0>,
 		// but guard against overflow.
 		const handledCPCountPlusOne = handledCPCount + 1;
 		if (m - n > floor((maxInt - delta) / handledCPCountPlusOne)) {
 			error('overflow');
 		}
 
 		delta += (m - n) * handledCPCountPlusOne;
 		n = m;
 
 		for (const currentValue of input) {
 			if (currentValue < n && ++delta > maxInt) {
 				error('overflow');
 			}
 			if (currentValue == n) {
 				// Represent delta as a generalized variable-length integer.
 				let q = delta;
 				for (let k = base; /* no condition */; k += base) {
 					const t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
 					if (q < t) {
 						break;
 					}
 					const qMinusT = q - t;
 					const baseMinusT = base - t;
 					output.push(
 						stringFromCharCode(digitToBasic(t + qMinusT % baseMinusT, 0))
 					);
 					q = floor(qMinusT / baseMinusT);
 				}
 
 				output.push(stringFromCharCode(digitToBasic(q, 0)));
 				bias = adapt(delta, handledCPCountPlusOne, handledCPCount == basicLength);
 				delta = 0;
 				++handledCPCount;
 			}
 		}
 
 		++delta;
 		++n;
 
 	}
 	return output.join('');
 };
 
 /**
  * Converts a Punycode string representing a domain name or an email address
  * to Unicode. Only the Punycoded parts of the input will be converted, i.e.
  * it doesn't matter if you call it on a string that has already been
  * converted to Unicode.
  * @memberOf punycode
  * @param {String} input The Punycoded domain name or email address to
  * convert to Unicode.
  * @returns {String} The Unicode representation of the given Punycode
  * string.
  */
 const toUnicode = function(input) {
 	return mapDomain(input, function(string) {
 		return regexPunycode.test(string)
 			? decode(string.slice(4).toLowerCase())
 			: string;
 	});
 };
 
 /**
  * Converts a Unicode string representing a domain name or an email address to
  * Punycode. Only the non-ASCII parts of the domain name will be converted,
  * i.e. it doesn't matter if you call it with a domain that's already in
  * ASCII.
  * @memberOf punycode
  * @param {String} input The domain name or email address to convert, as a
  * Unicode string.
  * @returns {String} The Punycode representation of the given domain name or
  * email address.
  */
 const toASCII = function(input) {
 	return mapDomain(input, function(string) {
 		return regexNonASCII.test(string)
 			? 'xn--' + encode(string)
 			: string;
 	});
 };
 
 /*--------------------------------------------------------------------------*/
 
 /** Define the public API */
 const punycode = {
 	/**
 	 * A string representing the current Punycode.js version number.
 	 * @memberOf punycode
 	 * @type String
 	 */
 	'version': '2.1.0',
 	/**
 	 * An object of methods to convert from JavaScript's internal character
 	 * representation (UCS-2) to Unicode code points, and back.
 	 * @see <https://mathiasbynens.be/notes/javascript-encoding>
 	 * @memberOf punycode
 	 * @type Object
 	 */
 	'ucs2': {
 		'decode': ucs2decode,
 		'encode': ucs2encode
 	},
 	'decode': decode,
 	'encode': encode,
 	'toASCII': toASCII,
 	'toUnicode': toUnicode
 };
 
 export { ucs2decode, ucs2encode, decode, encode, toASCII, toUnicode };
 export default punycode;