stringencoding/src/HZGB2312Encoder.js

Encode to/from Typed Array buffers

  /**
   * @constructor
   * @param {{fatal: boolean}} options
   */
  function HZGB2312Encoder(options) {
    var fatal = options.fatal;
    var hzgb2312 = false;
    /**
     * @param {ByteOutputStream} output_byte_stream Output byte stream.
     * @param {CodePointInputStream} code_point_pointer Input stream.
     * @return {number} The last byte emitted.
     */
    this.encode = function(output_byte_stream, code_point_pointer) {
      var code_point = code_point_pointer.get();
      if (code_point === EOF_code_point) {
        return EOF_byte;
      }
      code_point_pointer.offset(1);
      if (inRange(code_point, 0x0000, 0x007F) && hzgb2312) {
        code_point_pointer.offset(-1);
        hzgb2312 = false;
        return output_byte_stream.emit(0x7E, 0x7D);
      }
      if (code_point === 0x007E) {
        return output_byte_stream.emit(0x7E, 0x7E);
      }
      if (inRange(code_point, 0x0000, 0x007F)) {
        return output_byte_stream.emit(code_point);
      }
      if (!hzgb2312) {
        code_point_pointer.offset(-1);
        hzgb2312 = true;
        return output_byte_stream.emit(0x7E, 0x7B);
      }
      var pointer = indexPointerFor(code_point, indexes['gbk']);
      if (pointer === null) {
        return encoderError(code_point);
      }
      var lead = div(pointer, 190) + 1;
      var trail = pointer % 190 - 0x3F;
      if (!inRange(lead, 0x21, 0x7E) || !inRange(trail, 0x21, 0x7E)) {
        return encoderError(code_point);
      }
      return output_byte_stream.emit(lead, trail);
    };
  }