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Diffstat (limited to 'tools/node_modules/eslint/node_modules/chardet/encoding/iso2022.js')
| -rw-r--r-- | tools/node_modules/eslint/node_modules/chardet/encoding/iso2022.js | 141 |
1 files changed, 141 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/node_modules/chardet/encoding/iso2022.js b/tools/node_modules/eslint/node_modules/chardet/encoding/iso2022.js new file mode 100644 index 0000000000..afff88aec4 --- /dev/null +++ b/tools/node_modules/eslint/node_modules/chardet/encoding/iso2022.js @@ -0,0 +1,141 @@ +var util = require('util'), + Match = require ('../match'); + + +/** + * This is a superclass for the individual detectors for + * each of the detectable members of the ISO 2022 family + * of encodings. + */ + +function ISO_2022() {} + +ISO_2022.prototype.match = function(det) { + + /** + * Matching function shared among the 2022 detectors JP, CN and KR + * Counts up the number of legal an unrecognized escape sequences in + * the sample of text, and computes a score based on the total number & + * the proportion that fit the encoding. + * + * + * @param text the byte buffer containing text to analyse + * @param textLen the size of the text in the byte. + * @param escapeSequences the byte escape sequences to test for. + * @return match quality, in the range of 0-100. + */ + + var i, j; + var escN; + var hits = 0; + var misses = 0; + var shifts = 0; + var quality; + + // TODO: refactor me + var text = det.fInputBytes; + var textLen = det.fInputLen; + + scanInput: + for (i = 0; i < textLen; i++) { + if (text[i] == 0x1b) { + checkEscapes: + for (escN = 0; escN < this.escapeSequences.length; escN++) { + var seq = this.escapeSequences[escN]; + + if ((textLen - i) < seq.length) + continue checkEscapes; + + for (j = 1; j < seq.length; j++) + if (seq[j] != text[i + j]) + continue checkEscapes; + + + hits++; + i += seq.length - 1; + continue scanInput; + } + + misses++; + } + + // Shift in/out + if (text[i] == 0x0e || text[i] == 0x0f) + shifts++; + + } + + if (hits == 0) + return null; + + // + // Initial quality is based on relative proportion of recongized vs. + // unrecognized escape sequences. + // All good: quality = 100; + // half or less good: quality = 0; + // linear inbetween. + quality = (100 * hits - 100 * misses) / (hits + misses); + + // Back off quality if there were too few escape sequences seen. + // Include shifts in this computation, so that KR does not get penalized + // for having only a single Escape sequence, but many shifts. + if (hits + shifts < 5) + quality -= (5 - (hits + shifts)) * 10; + + return quality <= 0 ? null : new Match(det, this, quality); +}; + +module.exports.ISO_2022_JP = function() { + this.name = function() { + return 'ISO-2022-JP'; + }; + this.escapeSequences = [ + [ 0x1b, 0x24, 0x28, 0x43 ], // KS X 1001:1992 + [ 0x1b, 0x24, 0x28, 0x44 ], // JIS X 212-1990 + [ 0x1b, 0x24, 0x40 ], // JIS C 6226-1978 + [ 0x1b, 0x24, 0x41 ], // GB 2312-80 + [ 0x1b, 0x24, 0x42 ], // JIS X 208-1983 + [ 0x1b, 0x26, 0x40 ], // JIS X 208 1990, 1997 + [ 0x1b, 0x28, 0x42 ], // ASCII + [ 0x1b, 0x28, 0x48 ], // JIS-Roman + [ 0x1b, 0x28, 0x49 ], // Half-width katakana + [ 0x1b, 0x28, 0x4a ], // JIS-Roman + [ 0x1b, 0x2e, 0x41 ], // ISO 8859-1 + [ 0x1b, 0x2e, 0x46 ] // ISO 8859-7 + ]; +}; +util.inherits(module.exports.ISO_2022_JP, ISO_2022); + + + +module.exports.ISO_2022_KR = function() { + this.name = function() { + return 'ISO-2022-KR'; + }; + this.escapeSequences = [ + [ 0x1b, 0x24, 0x29, 0x43 ] + ]; +}; +util.inherits(module.exports.ISO_2022_KR, ISO_2022); + + + +module.exports.ISO_2022_CN = function() { + this.name = function() { + return 'ISO-2022-CN'; + }; + this.escapeSequences = [ + [ 0x1b, 0x24, 0x29, 0x41 ], // GB 2312-80 + [ 0x1b, 0x24, 0x29, 0x47 ], // CNS 11643-1992 Plane 1 + [ 0x1b, 0x24, 0x2A, 0x48 ], // CNS 11643-1992 Plane 2 + [ 0x1b, 0x24, 0x29, 0x45 ], // ISO-IR-165 + [ 0x1b, 0x24, 0x2B, 0x49 ], // CNS 11643-1992 Plane 3 + [ 0x1b, 0x24, 0x2B, 0x4A ], // CNS 11643-1992 Plane 4 + [ 0x1b, 0x24, 0x2B, 0x4B ], // CNS 11643-1992 Plane 5 + [ 0x1b, 0x24, 0x2B, 0x4C ], // CNS 11643-1992 Plane 6 + [ 0x1b, 0x24, 0x2B, 0x4D ], // CNS 11643-1992 Plane 7 + [ 0x1b, 0x4e ], // SS2 + [ 0x1b, 0x4f ] // SS3 + ]; +}; +util.inherits(module.exports.ISO_2022_CN, ISO_2022); |