用破折號字符轉換punycode爲Unicode

Question

我需要將punycode NIATO-OTABD轉換爲nñiñatoñ。

其他日子我發現a text converter in JavaScript，但是如果中間有短劃線，punycode轉換不起作用。

任何建議來解決「破折號」問題？

Answer 1

我花時間在下面創建了punycode。它基於RFC 3492中的C代碼。要將其與域名一起使用，必須將xn--從輸入/輸出中去除/添加到decode/encode。

utf16-class是必要的從JavaScripts內部字符表示轉換爲Unicode和回。

還有ToASCII和ToUnicode函數可以更容易地在puny編碼的IDN和ASCII之間進行轉換。

//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("."); 
    } 
}(); 

更新許可：
從RFC3492：

聲明和許可

對此整個文檔或它的任何部分（包括僞碼和C代碼），作者是沒有保證，並對由於使用造成的任何損害不承擔責任。作者授予不可撤銷的許可給任何人使用，修改和分發它，但不得以任何方式損害其他人使用，修改和分發其權利，前提是重新分發的衍生作品不包含誤導性作者或版本信息。衍生作品不需要根據類似條款獲得許可。

我把我的工作在這個punycode和utf16在公共領域。收到一封電子郵件告訴我你在使用它的項目中會很高興。