javascript - 将带有破折号字符的 punycode 转换为 Unicode

Question

我需要将 punycode NIATO-OTABD 转换为 nñiñatoñ。

我找到了a text converter in JavaScript前几天，但是如果中间有破折号，punycode 转换将不起作用。

有什么建议可以解决“破折号”问题吗？

Answer 1

我花时间创建了下面的 punycode。它基于 RFC 3492 中的 C 代码。要将其与域名一起使用，您必须从解码/编码的输入/输出中删除/添加 xn--。

utf16-class 是 JavaScript 内部字符表示形式与 unicode 之间相互转换所必需的。

还有 ToASCII 和 ToUnicode 函数，可以更轻松地在 puny 编码的 IDN 和 ASCII 之间进行转换。

//Javascript Punycode converter derived from example in RFC3492.
//This implementation is created by some@domain.name and released into public domain
var punycode = new function Punycode() {
    // This object converts to and from puny-code used in IDN
    //
    // punycode.ToASCII ( domain )
    // 
    // Returns a puny coded representation of "domain".
    // It only converts the part of the domain name that
    // has non ASCII characters. I.e. it dosent matter if
    // you call it with a domain that already is in ASCII.
    //
    // punycode.ToUnicode (domain)
    //
    // Converts a puny-coded domain name to unicode.
    // It only converts the puny-coded parts of the domain name.
    // I.e. it dosent matter if you call it on a string
    // that already has been converted to unicode.
    //
    //
    this.utf16 = {
        // The utf16-class is necessary to convert from javascripts internal character representation to unicode and back.
        decode:function(input){
            var output = [], i=0, len=input.length,value,extra;
            while (i < len) {
                value = input.charCodeAt(i++);
                if ((value & 0xF800) === 0xD800) {
                    extra = input.charCodeAt(i++);
                    if ( ((value & 0xFC00) !== 0xD800) || ((extra & 0xFC00) !== 0xDC00) ) {
                        throw new RangeError("UTF-16(decode): Illegal UTF-16 sequence");
                    }
                    value = ((value & 0x3FF) << 10) + (extra & 0x3FF) + 0x10000;
                }
                output.push(value);
            }
            return output;
        },
        encode:function(input){
            var output = [], i=0, len=input.length,value;
            while (i < len) {
                value = input[i++];
                if ( (value & 0xF800) === 0xD800 ) {
                    throw new RangeError("UTF-16(encode): Illegal UTF-16 value");
                }
                if (value > 0xFFFF) {
                    value -= 0x10000;
                    output.push(String.fromCharCode(((value >>>10) & 0x3FF) | 0xD800));
                    value = 0xDC00 | (value & 0x3FF);
                }
                output.push(String.fromCharCode(value));
            }
            return output.join("");
        }
    }

    //Default parameters
    var initial_n = 0x80;
    var initial_bias = 72;
    var delimiter = "\x2D";
    var base = 36;
    var damp = 700;
    var tmin=1;
    var tmax=26;
    var skew=38;
    var maxint = 0x7FFFFFFF;

    // decode_digit(cp) returns the numeric value of a basic code 
    // point (for use in representing integers) in the range 0 to
    // base-1, or base if cp is does not represent a value.

    function decode_digit(cp) {
        return cp - 48 < 10 ? cp - 22 : cp - 65 < 26 ? cp - 65 : cp - 97 < 26 ? cp - 97 : base;
    }

    // encode_digit(d,flag) returns the basic code point whose value
    // (when used for representing integers) is d, which needs to be in
    // the range 0 to base-1. The lowercase form is used unless flag is
    // nonzero, in which case the uppercase form is used. The behavior
    // is undefined if flag is nonzero and digit d has no uppercase form. 

    function encode_digit(d, flag) {
        return d + 22 + 75 * (d < 26) - ((flag != 0) << 5);
        //  0..25 map to ASCII a..z or A..Z 
        // 26..35 map to ASCII 0..9
    }
    //** Bias adaptation function **
    function adapt(delta, numpoints, firsttime ) {
        var k;
        delta = firsttime ? Math.floor(delta / damp) : (delta >> 1);
        delta += Math.floor(delta / numpoints);

        for (k = 0; delta > (((base - tmin) * tmax) >> 1); k += base) {
                delta = Math.floor(delta / ( base - tmin ));
        }
        return Math.floor(k + (base - tmin + 1) * delta / (delta + skew));
    }

    // encode_basic(bcp,flag) forces a basic code point to lowercase if flag is zero,
    // uppercase if flag is nonzero, and returns the resulting code point.
    // The code point is unchanged if it is caseless.
    // The behavior is undefined if bcp is not a basic code point.

    function encode_basic(bcp, flag) {
        bcp -= (bcp - 97 < 26) << 5;
        return bcp + ((!flag && (bcp - 65 < 26)) << 5);
    }

    // Main decode
    this.decode=function(input,preserveCase) {
        // Dont use utf16
        var output=[];
        var case_flags=[];
        var input_length = input.length;

        var n, out, i, bias, basic, j, ic, oldi, w, k, digit, t, len;

        // Initialize the state: 

        n = initial_n;
        i = 0;
        bias = initial_bias;

        // 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(preserveCase) case_flags[output.length] = ( input.charCodeAt(j) -65 < 26);
            if ( input.charCodeAt(j) >= 0x80) {
                throw new RangeError("Illegal input >= 0x80");
            }
            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 (ic = basic > 0 ? basic + 1 : 0; ic < input_length; ) {

            // ic 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; ; k += base) {
                    if (ic >= input_length) {
                        throw RangeError ("punycode_bad_input(1)");
                    }
                    digit = decode_digit(input.charCodeAt(ic++));

                    if (digit >= base) {
                        throw RangeError("punycode_bad_input(2)");
                    }
                    if (digit > Math.floor((maxint - i) / w)) {
                        throw RangeError ("punycode_overflow(1)");
                    }
                    i += digit * w;
                    t = k <= bias ? tmin : k >= bias + tmax ? tmax : k - bias;
                    if (digit < t) { break; }
                    if (w > Math.floor(maxint / (base - t))) {
                        throw RangeError("punycode_overflow(2)");
                    }
                    w *= (base - t);
            }

            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 ( Math.floor(i / out) > maxint - n) {
                throw RangeError("punycode_overflow(3)");
            }
            n += Math.floor( i / out ) ;
            i %= out;

            // Insert n at position i of the output: 
            // Case of last character determines uppercase flag: 
            if (preserveCase) { case_flags.splice(i, 0, input.charCodeAt(ic -1) -65 < 26);}

            output.splice(i, 0, n);
            i++;
        }
        if (preserveCase) {
            for (i = 0, len = output.length; i < len; i++) {
                if (case_flags[i]) {
                    output[i] = (String.fromCharCode(output[i]).toUpperCase()).charCodeAt(0);
                }
            }
        }
        return this.utf16.encode(output);
    };

    //** Main encode function **

    this.encode = function (input,preserveCase) {
        //** Bias adaptation function **

        var n, delta, h, b, bias, j, m, q, k, t, ijv, case_flags;

        if (preserveCase) {
            // Preserve case, step1 of 2: Get a list of the unaltered string
            case_flags = this.utf16.decode(input);
        }
        // Converts the input in UTF-16 to Unicode
        input = this.utf16.decode(input.toLowerCase());

        var input_length = input.length; // Cache the length

        if (preserveCase) {
            // Preserve case, step2 of 2: Modify the list to true/false
            for (j=0; j < input_length; j++) {
                case_flags[j] = input[j] != case_flags[j];
            }
        }

        var output=[];


        // Initialize the state: 
        n = initial_n;
        delta = 0;
        bias = initial_bias;

        // Handle the basic code points: 
        for (j = 0; j < input_length; ++j) {
            if ( input[j] < 0x80) {
                output.push(
                    String.fromCharCode(
                        case_flags ? encode_basic(input[j], case_flags[j]) : input[j]
                    )
                );
            }
        }

        h = b = output.length;

        // h is the number of code points that have been handled, b is the
        // number of basic code points 

        if (b > 0) output.push(delimiter);

        // Main encoding loop: 
        //
        while (h < input_length) {
            // All non-basic code points < n have been
            // handled already. Find the next larger one: 

            for (m = maxint, j = 0; j < input_length; ++j) {
                ijv = input[j];
                if (ijv >= n && ijv < m) m = ijv;
            }

            // Increase delta enough to advance the decoder's
            // <n,i> state to <m,0>, but guard against overflow: 

            if (m - n > Math.floor((maxint - delta) / (h + 1))) {
                throw RangeError("punycode_overflow (1)");
            }
            delta += (m - n) * (h + 1);
            n = m;

            for (j = 0; j < input_length; ++j) {
                ijv = input[j];

                if (ijv < n ) {
                    if (++delta > maxint) return Error("punycode_overflow(2)");
                }

                if (ijv == n) {
                    // Represent delta as a generalized variable-length integer: 
                    for (q = delta, k = base; ; k += base) {
                        t = k <= bias ? tmin : k >= bias + tmax ? tmax : k - bias;
                        if (q < t) break;
                        output.push( String.fromCharCode(encode_digit(t + (q - t) % (base - t), 0)) );
                        q = Math.floor( (q - t) / (base - t) );
                    }
                    output.push( String.fromCharCode(encode_digit(q, preserveCase && case_flags[j] ? 1:0 )));
                    bias = adapt(delta, h + 1, h == b);
                    delta = 0;
                    ++h;
                }
            }

            ++delta, ++n;
        }
        return output.join("");
    }

    this.ToASCII = function ( domain ) {
        var domain_array = domain.split(".");
        var out = [];
        for (var i=0; i < domain_array.length; ++i) {
            var s = domain_array[i];
            out.push(
                s.match(/[^A-Za-z0-9-]/) ?
                "xn--" + punycode.encode(s) :
                s
            );
        }
        return out.join(".");
    }
    this.ToUnicode = function ( domain ) {
        var domain_array = domain.split(".");
        var out = [];
        for (var i=0; i < domain_array.length; ++i) {
            var s = domain_array[i];
            out.push(
                s.match(/^xn--/) ?
                punycode.decode(s.slice(4)) :
                s
            );
        }
        return out.join(".");
    }
}();


// Example of usage:
domain.oninput = function() {
    var input = domain.value
    var ascii = punycode.ToASCII(input)
    var display = punycode.ToUnicode(ascii)
    domain_ascii.value = ascii
    domain_display.value = display
}

<p>Try with your own data</p>

<label>
  <div>Input domain</div>
  <div><input id="domain" type="text"></div>
</label>
<div>Ascii: <output id="domain_ascii"></div>
<div>Display: <output id="domain_display"></div>

许可证:

来自 RFC3492:

Disclaimer and license

Regarding this entire document or any portion of it (including the pseudocode and C code), the author makes no guarantees and is not responsible for any damage resulting from its use. The author grants irrevocable permission to anyone to use, modify, and distribute it in any way that does not diminish the rights of anyone else to use, modify, and distribute it, provided that redistributed derivative works do not contain misleading author or version information. Derivative works need not be licensed under similar terms.

我将我的作品放入公共(public)领域的 punycode 和 utf16 中。如果能收到一封电子邮件告诉我您在哪个项目中使用它，那就太好了。

代码的范围

每个 TLD 都有允许使用代码点的规则。下面代码的范围是在 punycode 和 javascript 使用的内部编码之间对字符串进行编码和解码(考虑到这些规则)。根据您的用例，您可能需要过滤字符串。例如，0xFE0F:变体选择器-16，一个不可见的代码点，指定前一个字符应与表情符号一起显示。如果您搜索“IDN 中允许的代码点”，您应该会找到几个可以帮助您过滤字符串的项目。