Issue 4350 - Update punycode.js to 2.0.0

lib/punycode.js

-/*! http://mths.be/punycode v1.2.3 by @mathias */
-/* Used under GPL 2.0, see https://github.com/bestiejs/punycode.js/blob/master/LICENSE-GPL.txt */
-;(function() {
+'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 = /[^\x20-\x7E]/; // unprintable ASCII chars + 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 = {
         /**
-         * The `punycode` object.
-         * @name punycode
+         * A string representing the current Punycode.js version number.
+         * @memberOf punycode
+         * @type String
+         */
+        'version': '2.0.0',
+        /**
+         * 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
          */
-        var punycode,
-
-        /** Highest positive signed 32-bit float value */
-        maxInt = 2147483647, // aka. 0x7FFFFFFF or 2^31-1
-
-        /** Bootstring parameters */
-        base = 36,
-        tMin = 1,
-        tMax = 26,
-        skew = 38,
-        damp = 700,
-        initialBias = 72,
-        initialN = 128, // 0x80
-        delimiter = '-', // '\x2D'
-
-        /** Regular expressions */
-        regexPunycode = /^xn--/,
-        regexNonASCII = /[^ -~]/, // unprintable ASCII chars + non-ASCII chars
-        regexSeparators = /\x2E|\u3002|\uFF0E|\uFF61/g, // RFC 3490 separators
-
-        /** Error messages */
-        errors = {
-                'overflow': 'Overflow: input needs wider integers to process',
-                'not-basic': 'Illegal input >= 0x80 (not a basic code point)',
-                'invalid-input': 'Invalid input'
+        'ucs2': {
+                'decode': ucs2decode,
+                'encode': ucs2encode
         },
-
-        /** Convenience shortcuts */
-        baseMinusTMin = base - tMin,
-        floor = Math.floor,
-        stringFromCharCode = String.fromCharCode,
-
-        /** Temporary variable */
-        key;
-
-        /*--------------------------------------------------------------------------*/
-
-        /**
-         * 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 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) {
-                var length = array.length;
-                while (length--) {
-                        array[length] = fn(array[length]);
-                }
-                return array;
-        }
-
-        /**
-         * A simple `Array#map`-like wrapper to work with domain name strings.
-         * @private
-         * @param {String} domain The domain name.
-         * @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) {
-                return map(string.split(regexSeparators), fn).join('.');
-        }
-
-        /**
-         * 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 <http://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) {
-                var output = [],
-                    counter = 0,
-                    length = string.length,
-                    value,
-                    extra;
-                while (counter < length) {
-                        value = string.charCodeAt(counter++);
-                        if (value >= 0xD800 && value <= 0xDBFF && counter < length) {
-                                // high surrogate, and there is a next character
-                                extra = string.charCodeAt(counter++);
-                                if ((extra & 0xFC00) == 0xDC00) { // low surrogate
-                                        output.push(((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000);
-                                } else {
-                                        // 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).
-         */
-        function ucs2encode(array) {
-                return map(array, function(value) {
-                        var output = '';
-                        if (value > 0xFFFF) {
-                                value -= 0x10000;
-                                output += stringFromCharCode(value >>> 10 & 0x3FF | 0xD800);
-                                value = 0xDC00 | value & 0x3FF;
-                        }
-                        output += stringFromCharCode(value);
-                        return output;
-                }).join('');
-        }
-
-        /**
-         * 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.
-         */
-        function basicToDigit(codePoint) {
-                if (codePoint - 48 < 10) {
-                        return codePoint - 22;
-                }
-                if (codePoint - 65 < 26) {
-                        return codePoint - 65;
-                }
-                if (codePoint - 97 < 26) {
-                        return codePoint - 97;
-                }
-                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.
-         */
-        function digitToBasic(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.
-         * http://tools.ietf.org/html/rfc3492#section-3.4
-         * @private
-         */
-        function adapt(delta, numPoints, firstTime) {
-                var 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.
-         */
-        function decode(input) {
-                // Don't use UCS-2
-                var output = [],
-                    inputLength = input.length,
-                    out,
-                    i = 0,
-                    n = initialN,
-                    bias = initialBias,
-                    basic,
-                    j,
-                    index,
-                    oldi,
-                    w,
-                    k,
-                    digit,
-                    t,
-                    length,
-                    /** Cached calculation results */
-                    baseMinusT;
-
-                // 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.
-
-                basic = input.lastIndexOf(delimiter);
-                if (basic < 0) {
-                        basic = 0;
-                }
-
-                for (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 (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`.
-                        for (oldi = i, w = 1, k = base; /* no condition */; k += base) {
-
-                                if (index >= inputLength) {
-                                        error('invalid-input');
-                                }
-
-                                digit = basicToDigit(input.charCodeAt(index++));
-
-                                if (digit >= base || digit > floor((maxInt - i) / w)) {
-                                        error('overflow');
-                                }
-
-                                i += digit * w;
-                                t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
-
-                                if (digit < t) {
-                                        break;
-                                }
-
-                                baseMinusT = base - t;
-                                if (w > floor(maxInt / baseMinusT)) {
-                                        error('overflow');
-                                }
-
-                                w *= baseMinusT;
-
-                        }
-
-                        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 ucs2encode(output);
-        }
-
-        /**
-         * Converts a string of Unicode symbols 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.
-         */
-        function encode(input) {
-                var n,
-                    delta,
-                    handledCPCount,
-                    basicLength,
-                    bias,
-                    j,
-                    m,
-                    q,
-                    k,
-                    t,
-                    currentValue,
-                    output = [],
-                    /** `inputLength` will hold the number of code points in `input`. */
-                    inputLength,
-                    /** Cached calculation results */
-                    handledCPCountPlusOne,
-                    baseMinusT,
-                    qMinusT;
-
-                // Convert the input in UCS-2 to Unicode
-                input = ucs2decode(input);
-
-                // Cache the length
-                inputLength = input.length;
-
-                // Initialize the state
-                n = initialN;
-                delta = 0;
-                bias = initialBias;
-
-                // Handle the basic code points
-                for (j = 0; j < inputLength; ++j) {
-                        currentValue = input[j];
-                        if (currentValue < 0x80) {
-                                output.push(stringFromCharCode(currentValue));
-                        }
-                }
-
-                handledCPCount = basicLength = output.length;
-
-                // `handledCPCount` is the number of code points that have been handled;
-                // `basicLength` is the number of basic code points.
-
-                // Finish the basic string - if it is not empty - with a delimiter
-                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:
-                        for (m = maxInt, j = 0; j < inputLength; ++j) {
-                                currentValue = input[j];
-                                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
-                        handledCPCountPlusOne = handledCPCount + 1;
-                        if (m - n > floor((maxInt - delta) / handledCPCountPlusOne)) {
-                                error('overflow');
-                        }
-
-                        delta += (m - n) * handledCPCountPlusOne;
-                        n = m;
-
-                        for (j = 0; j < inputLength; ++j) {
-                                currentValue = input[j];
-
-                                if (currentValue < n && ++delta > maxInt) {
-                                        error('overflow');
-                                }
-
-                                if (currentValue == n) {
-                                        // Represent delta as a generalized variable-length integer
-                                        for (q = delta, k = base; /* no condition */; k += base) {
-                                                t = k <= bias ? tMin : (k >= bias + tMax ? tMax : k - bias);
-                                                if (q < t) {
-                                                        break;
-                                                }
-                                                qMinusT = q - t;
-                                                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 to Unicode. Only the
-         * Punycoded parts of the domain name 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} domain The Punycode domain name to convert to Unicode.
-         * @returns {String} The Unicode representation of the given Punycode
-         * string.
-         */
-        function toUnicode(domain) {
-                return mapDomain(domain, function(string) {
-                        return regexPunycode.test(string)
-                                ? decode(string.slice(4).toLowerCase())
-                                : string;
-                });
-        }
-
-        /**
-         * Converts a Unicode string representing a domain name 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} domain The domain name to convert, as a Unicode string.
-         * @returns {String} The Punycode representation of the given domain name.
-         */
-        function toASCII(domain) {
-                return mapDomain(domain, function(string) {
-                        return regexNonASCII.test(string)
-                                ? 'xn--' + encode(string)
-                                : string;
-                });
-        }
-
-        /*--------------------------------------------------------------------------*/
-
-        /** Define the public API */
-        exports = {
-                /**
-                 * A string representing the current Punycode.js version number.
-                 * @memberOf punycode
-                 * @type String
-                 */
-                'version': '1.2.3',
-                /**
-                 * An object of methods to convert from JavaScript's internal character
-                 * representation (UCS-2) to Unicode code points, and back.
-                 * @see <http://mathiasbynens.be/notes/javascript-encoding>
-                 * @memberOf punycode
-                 * @type Object
-                 */
-                'ucs2': {
-                        'decode': ucs2decode,
-                        'encode': ucs2encode
-                },
-                'decode': decode,
-                'encode': encode,
-                'toASCII': toASCII,
-                'toUnicode': toUnicode
-        };
-}());
+        'decode': decode,
+        'encode': encode,
+        'toASCII': toASCII,
+        'toUnicode': toUnicode
+};
+
+module.exports = punycode;