code: func (r *errorReader) ltf8() int64 {
  	var buf [9]byte
  	_, r.err = io.ReadFull(r, buf[:1])
  	if r.err != nil {
  		return 0
  	}
  	i, n, ok := ltf8.Decode(buf[:1])
  	if ok {
  		return i
  	}
  	_, r.err = io.ReadFull(r, buf[1:n])
  	if r.err != nil {
  		return 0
  	}
  	i, _, ok = ltf8.Decode(buf[:n])
  	if !ok {
  		r.err = fmt.Errorf("cram: failed to decode ltf-8 stream %#v", buf[:n])
  	}
  	return i
  }
docs: // itf8 returns the LTF-8 encoded number at the current reader position.