@zxing/text-encoding
Version:
Polyfill for the Encoding Living Standard's API.
82 lines • 3.72 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
var encodings_1 = require("../../encoding/encodings");
var finished_1 = require("../../encoding/finished");
var indexes_1 = require("../../encoding/indexes");
var terminology_1 = require("../../encoding/terminology");
/**
* @constructor
* @implements {Encoder}
* @param {{fatal: boolean}} options
* @param {boolean=} gbk_flag
*/
var GB18030Encoder = /** @class */ (function () {
function GB18030Encoder(options, gbk_flag) {
if (gbk_flag === void 0) { gbk_flag = undefined; }
this.gbk_flag = gbk_flag;
this.fatal = options.fatal;
// gb18030's decoder has an associated gbk flag (initially unset).
}
/**
* @param {Stream} stream Input stream.
* @param {number} code_point Next code point read from the stream.
* @return {(number|!Array.<number>)} Byte(s) to emit.
*/
GB18030Encoder.prototype.handler = function (stream, code_point) {
// 1. If code point is end-of-stream, return finished.
if (code_point === terminology_1.end_of_stream)
return finished_1.finished;
// 2. If code point is an ASCII code point, return a byte whose
// value is code point.
if (terminology_1.isASCIICodePoint(code_point))
return code_point;
// 3. If code point is U+E5E5, return error with code point.
if (code_point === 0xE5E5)
return encodings_1.encoderError(code_point);
// 4. If the gbk flag is set and code point is U+20AC, return
// byte 0x80.
if (this.gbk_flag && code_point === 0x20AC)
return 0x80;
// 5. Let pointer be the index pointer for code point in index
// gb18030.
var pointer = indexes_1.indexPointerFor(code_point, indexes_1.index('gb18030'));
// 6. If pointer is not null, run these substeps:
if (pointer !== null) {
// 1. Let lead be Math.floor(pointer / 190) + 0x81.
var lead = Math.floor(pointer / 190) + 0x81;
// 2. Let trail be pointer % 190.
var trail = pointer % 190;
// 3. Let offset be 0x40 if trail is less than 0x3F and 0x41 otherwise.
var offset = trail < 0x3F ? 0x40 : 0x41;
// 4. Return two bytes whose values are lead and trail + offset.
return [lead, trail + offset];
}
// 7. If gbk flag is set, return error with code point.
if (this.gbk_flag)
return encodings_1.encoderError(code_point);
// 8. Set pointer to the index gb18030 ranges pointer for code
// point.
pointer = indexes_1.indexGB18030RangesPointerFor(code_point);
// 9. Let byte1 be Math.floor(pointer / 10 / 126 / 10).
var byte1 = Math.floor(pointer / 10 / 126 / 10);
// 10. Set pointer to pointer − byte1 × 10 × 126 × 10.
pointer = pointer - byte1 * 10 * 126 * 10;
// 11. Let byte2 be Math.floor(pointer / 10 / 126).
var byte2 = Math.floor(pointer / 10 / 126);
// 12. Set pointer to pointer − byte2 × 10 × 126.
pointer = pointer - byte2 * 10 * 126;
// 13. Let byte3 be Math.floor(pointer / 10).
var byte3 = Math.floor(pointer / 10);
// 14. Let byte4 be pointer − byte3 × 10.
var byte4 = pointer - byte3 * 10;
// 15. Return four bytes whose values are byte1 + 0x81, byte2 +
// 0x30, byte3 + 0x81, byte4 + 0x30.
return [byte1 + 0x81,
byte2 + 0x30,
byte3 + 0x81,
byte4 + 0x30];
};
return GB18030Encoder;
}());
exports.GB18030Encoder = GB18030Encoder;
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