asciiblaster

- draw irc art in your web browser
git clone git://git.acid.vegas/asciiblaster.git
text-encoder-lite.js (3463B)
      1 // taken from https://github.com/coolaj86/TextEncoderLite/blob/master/index.js
      2 // added polyfill at bottom
      3 
      4 function TextEncoderLite() {
      5 }
      6 function TextDecoderLite() {
      7 }
      8 
      9 (function () {
     10 'use strict';
     11 
     12 // Taken from https://github.com/feross/buffer/blob/master/index.js
     13 // Thanks Feross et al! :-)
     14 
     15 function utf8ToBytes (string, units) {
     16   units = units || Infinity
     17   var codePoint
     18   var length = string.length
     19   var leadSurrogate = null
     20   var bytes = []
     21   var i = 0
     22 
     23   for (; i < length; i++) {
     24     codePoint = string.charCodeAt(i)
     25 
     26     // is surrogate component
     27     if (codePoint > 0xD7FF && codePoint < 0xE000) {
     28       // last char was a lead
     29       if (leadSurrogate) {
     30         // 2 leads in a row
     31         if (codePoint < 0xDC00) {
     32           if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
     33           leadSurrogate = codePoint
     34           continue
     35         } else {
     36           // valid surrogate pair
     37           codePoint = leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00 | 0x10000
     38           leadSurrogate = null
     39         }
     40       } else {
     41         // no lead yet
     42 
     43         if (codePoint > 0xDBFF) {
     44           // unexpected trail
     45           if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
     46           continue
     47         } else if (i + 1 === length) {
     48           // unpaired lead
     49           if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
     50           continue
     51         } else {
     52           // valid lead
     53           leadSurrogate = codePoint
     54           continue
     55         }
     56       }
     57     } else if (leadSurrogate) {
     58       // valid bmp char, but last char was a lead
     59       if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
     60       leadSurrogate = null
     61     }
     62 
     63     // encode utf8
     64     if (codePoint < 0x80) {
     65       if ((units -= 1) < 0) break
     66       bytes.push(codePoint)
     67     } else if (codePoint < 0x800) {
     68       if ((units -= 2) < 0) break
     69       bytes.push(
     70         codePoint >> 0x6 | 0xC0,
     71         codePoint & 0x3F | 0x80
     72       )
     73     } else if (codePoint < 0x10000) {
     74       if ((units -= 3) < 0) break
     75       bytes.push(
     76         codePoint >> 0xC | 0xE0,
     77         codePoint >> 0x6 & 0x3F | 0x80,
     78         codePoint & 0x3F | 0x80
     79       )
     80     } else if (codePoint < 0x200000) {
     81       if ((units -= 4) < 0) break
     82       bytes.push(
     83         codePoint >> 0x12 | 0xF0,
     84         codePoint >> 0xC & 0x3F | 0x80,
     85         codePoint >> 0x6 & 0x3F | 0x80,
     86         codePoint & 0x3F | 0x80
     87       )
     88     } else {
     89       throw new Error('Invalid code point')
     90     }
     91   }
     92 
     93   return bytes
     94 }
     95 
     96 function utf8Slice (buf, start, end) {
     97   var res = ''
     98   var tmp = ''
     99   end = Math.min(buf.length, end || Infinity)
    100   start = start || 0;
    101 
    102   for (var i = start; i < end; i++) {
    103     if (buf[i] <= 0x7F) {
    104       res += decodeUtf8Char(tmp) + String.fromCharCode(buf[i])
    105       tmp = ''
    106     } else {
    107       tmp += '%' + buf[i].toString(16)
    108     }
    109   }
    110 
    111   return res + decodeUtf8Char(tmp)
    112 }
    113 
    114 function decodeUtf8Char (str) {
    115   try {
    116     return decodeURIComponent(str)
    117   } catch (err) {
    118     return String.fromCharCode(0xFFFD) // UTF 8 invalid char
    119   }
    120 }
    121 
    122 TextEncoderLite.prototype.encode = function (str) {
    123   var result;
    124 
    125   if ('undefined' === typeof Uint8Array) {
    126     result = utf8ToBytes(str);
    127   } else {
    128     result = new Uint8Array(utf8ToBytes(str));
    129   }
    130 
    131   return result;
    132 };
    133 
    134 TextDecoderLite.prototype.decode = function (bytes) {
    135   return utf8Slice(bytes, 0, bytes.length);
    136 }
    137 
    138 }());
    139 
    140 if (typeof TextEncoder === 'undefined') TextEncoder = TextEncoderLite
    141 if (typeof TextDecoder === 'undefined') TextDecoder = TextDecoderLite