Big5Encoder.js 2.1 KB

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  1. "use strict";
  2. Object.defineProperty(exports, "__esModule", { value: true });
  3. var encodings_1 = require("../../encoding/encodings");
  4. var finished_1 = require("../../encoding/finished");
  5. var indexes_1 = require("../../encoding/indexes");
  6. var terminology_1 = require("../../encoding/terminology");
  7. /**
  8. * @constructor
  9. * @implements {Encoder}
  10. * @param {{fatal: boolean}} options
  11. */
  12. var Big5Encoder = /** @class */ (function () {
  13. function Big5Encoder(options) {
  14. this.fatal = options.fatal;
  15. }
  16. /**
  17. * @param {Stream} stream Input stream.
  18. * @param {number} code_point Next code point read from the stream.
  19. * @return {(number|!Array.<number>)} Byte(s) to emit.
  20. */
  21. Big5Encoder.prototype.handler = function (stream, code_point) {
  22. // 1. If code point is end-of-stream, return finished.
  23. if (code_point === terminology_1.end_of_stream)
  24. return finished_1.finished;
  25. // 2. If code point is an ASCII code point, return a byte whose
  26. // value is code point.
  27. if (terminology_1.isASCIICodePoint(code_point))
  28. return code_point;
  29. // 3. Let pointer be the index Big5 pointer for code point.
  30. var pointer = indexes_1.indexBig5PointerFor(code_point);
  31. // 4. If pointer is null, return error with code point.
  32. if (pointer === null)
  33. return encodings_1.encoderError(code_point);
  34. // 5. Let lead be Math.floor(pointer / 157) + 0x81.
  35. var lead = Math.floor(pointer / 157) + 0x81;
  36. // 6. If lead is less than 0xA1, return error with code point.
  37. if (lead < 0xA1)
  38. return encodings_1.encoderError(code_point);
  39. // 7. Let trail be pointer % 157.
  40. var trail = pointer % 157;
  41. // 8. Let offset be 0x40 if trail is less than 0x3F and 0x62
  42. // otherwise.
  43. var offset = trail < 0x3F ? 0x40 : 0x62;
  44. // Return two bytes whose values are lead and trail + offset.
  45. return [lead, trail + offset];
  46. };
  47. return Big5Encoder;
  48. }());
  49. exports.Big5Encoder = Big5Encoder;
  50. //# sourceMappingURL=Big5Encoder.js.map