srecord ByteCountingLineReader(InputStream in) { // in should be buffered!
  long byteCount;
  int bufferedByte = -1;
  bool ended;
  
  S readLine() ctex {
    new StringBuilder buf;
    int c;
    while (licensed() && !ended) {
      int c = read();
      if (c == '\n') break;
      if (c == '\r') {
        c = read();
        if (c != '\n' && !ended)
          bufferedByte = c;
        break;
      }
    }
    ret buf.toString();
  }
  
  int read() ctex {
    if (bufferedByte >= 0) {
      int b = bufferedByte;
      bufferedByte = -1;
      ret b;
    }
    int c = in.read();
    if (c < 0) ended = true;
    ret c;
  }
}