if len(s) < 2 {
			return Properties{}, 0
		}
		i := bidiIndex[c0]
		c1 := s[1]
		if c1 < 0x80 || 0xC0 <= c1 {
			return Properties{}, 1
		}
		return Properties{entry: trie.lookupValue(uint32(i), c1)}, 2
	case c0 < 0xF0: // 3-byte UTF-8
		if len(s) < 3 {
			return Properties{}, 0
		}
		i := bidiIndex[c0]
		c1 := s[1]
		if c1 < 0x80 || 0xC0 <= c1 {
			return Properties{}, 1
		}

	Hungarian            Tag = Tag{language: huIndex, locale: huIndex}
	Armenian             Tag = Tag{language: hyIndex, locale: hyIndex}
	Indonesian           Tag = Tag{language: idIndex, locale: idIndex}
	Icelandic            Tag = Tag{language: isIndex, locale: isIndex}
	Italian              Tag = Tag{language: itIndex, locale: itIndex}
	Japanese             Tag = Tag{language: jaIndex, locale: jaIndex}

          swap(array, from, to);
        }
        return array[k];
      } else {
        int midIndex = (from + to) >>> 1;
        // Choose the median of the elements at the from, to and mid indexes,
        // and rearrange so that array[from]<=array[from+1], and
        // array[to] => array[from + 1].

        swap(array, midIndex, from + 1);

        if (array[from] > array[to]) {
          swap(array, from, to);
        }

// It also enables debugging checks during the encoding.
func (w *Writer) Debug(out io.Writer) {
	w.debug = out
}

// BitIndex returns the number of bits written to the bit stream so far.
func (w *Writer) BitIndex() int64 {
	return w.index
}

// byte writes the byte x to the output.
func (w *Writer) byte(x byte) {
	if w.debug != nil {
		w.debugBuf = append(w.debugBuf, x)
	}