iso2022jp-decoder.js (6941B)
1 function dec2char(n) { 2 // converts a decimal number to a Unicode character 3 // n: the dec codepoint value to be converted 4 if (n <= 0xffff) { 5 out = String.fromCharCode(n); 6 } else if (n <= 0x10ffff) { 7 n -= 0x10000; 8 out = 9 String.fromCharCode(0xd800 | (n >> 10)) + 10 String.fromCharCode(0xdc00 | (n & 0x3ff)); 11 } else out = "dec2char error: Code point out of range: " + n; 12 return out; 13 } 14 15 function getIndexPtr(cp, index) { 16 for (p = 0; p < index.length; p++) { 17 if (index[p] == cp) { 18 return p; 19 } 20 } 21 return null; 22 } 23 24 function iso2022jpDecoder(stream) { 25 stream = stream.replace(/%/g, " "); 26 stream = stream.replace(/[\s]+/g, " ").trim(); 27 var bytes = stream.split(" "); 28 for (var i = 0; i < bytes.length; i++) bytes[i] = parseInt(bytes[i], 16); 29 var endofstream = 2000000; 30 //bytes.push(endofstream) 31 var out = ""; 32 var decState = "ascii"; 33 var outState = "ascii"; 34 var isoLead = 0x00; 35 var outFlag = false; 36 var cp, ptr, lead; 37 38 var finished = false; 39 while (!finished) { 40 if (bytes.length == 0) byte = endofstream; 41 else var byte = bytes.shift(); 42 //byte = bytes.shift() 43 44 switch (decState) { 45 case "ascii": 46 if (byte == 0x1b) { 47 decState = "escStart"; 48 continue; 49 } else if ( 50 byte >= 0x00 && 51 byte <= 0x7f && 52 byte !== 0x0e && 53 byte !== 0x0f && 54 byte !== 0x1b 55 ) { 56 outFlag = false; 57 out += dec2char(byte); 58 continue; 59 } else if (byte == endofstream) { 60 finished = true; 61 continue; 62 } else { 63 outFlag = false; 64 out += "�"; 65 continue; 66 } 67 break; 68 case "roman": 69 if (byte == 0x1b) { 70 decState = "escStart"; 71 continue; 72 } else if (byte == 0x5c) { 73 outFlag = false; 74 out += dec2char(0xa5); 75 continue; 76 } else if (byte == 0x7e) { 77 outFlag = false; 78 out += dec2char(0x203e); 79 continue; 80 } else if ( 81 byte >= 0x00 && 82 byte <= 0x7f && 83 byte !== 0x0e && 84 byte !== 0x0f && 85 byte !== 0x1b && 86 byte !== 0x5c && 87 byte !== 0x7e 88 ) { 89 outFlag = false; 90 out += dec2char(byte); 91 continue; 92 } else if (byte == endofstream) { 93 finished = true; 94 continue; 95 } else { 96 outFlag = false; 97 out += "�"; 98 continue; 99 } 100 break; 101 case "katakana": 102 if (byte == 0x1b) { 103 decState = "escStart"; 104 continue; 105 } else if (byte >= 0x21 && byte <= 0x5f) { 106 outFlag = false; 107 out += dec2char(0xff61 + byte - 0x21); 108 continue; 109 } else if (byte == endofstream) { 110 finished = true; 111 continue; 112 } else { 113 outFlag = false; 114 out += "�"; 115 continue; 116 } 117 break; 118 case "leadbyte": 119 if (byte == 0x1b) { 120 decState = "escStart"; 121 continue; 122 } else if (byte >= 0x21 && byte <= 0x7e) { 123 outFlag = false; 124 isoLead = byte; 125 decState = "trailbyte"; 126 continue; 127 } else if (byte == endofstream) { 128 finished = true; 129 continue; 130 } else { 131 outFlag = false; 132 out += "�"; 133 continue; 134 } 135 break; 136 case "trailbyte": 137 if (byte == 0x1b) { 138 decState = "escStart"; 139 out += "�"; 140 continue; 141 } else if (byte >= 0x21 && byte <= 0x7e) { 142 decState = "leadbyte"; 143 ptr = (isoLead - 0x21) * 94 + byte - 0x21; 144 cp = jis0208[ptr]; 145 if (cp == null) { 146 out += "�"; 147 continue; 148 } 149 out += dec2char(cp); 150 continue; 151 } else if (byte == endofstream) { 152 decState = "leadbyte"; 153 bytes.unshift(byte); 154 out += "�"; 155 continue; 156 } else { 157 decState = "leadbyte"; 158 out += "�"; 159 continue; 160 } 161 break; 162 case "escStart": 163 if (byte == 0x24 || byte == 0x28) { 164 isoLead = byte; 165 decState = "escape"; 166 continue; 167 } else { 168 bytes.unshift(byte); 169 outFlag = false; 170 decState = outState; 171 out += "�"; 172 continue; 173 } 174 break; 175 case "escape": 176 lead = isoLead; 177 isoLead = 0x00; 178 var state = null; 179 if (lead == 0x28 && byte == 0x42) state = "ascii"; 180 if (lead == 0x28 && byte == 0x4a) state = "roman"; 181 if (lead == 0x28 && byte == 0x49) state = "katakana"; 182 if (lead == 0x24 && (byte == 0x40 || byte == 0x42)) 183 state = "leadbyte"; 184 if (state != null) { 185 decState = state; 186 outState = state; 187 var outputflag = false; 188 outputflag = outFlag; 189 outFlag = true; 190 if (outputflag == false) continue; 191 else { 192 out += "�"; 193 continue; 194 } 195 } 196 // Prepend the sequence (lead, byte) to the stream 197 bytes.unshift(lead, byte); 198 outFlag = false; 199 decState = outState; 200 out += "�"; 201 continue; 202 break; 203 } 204 } 205 return out; 206 }