func searchUint(imap []uint16, key uint16) int {
	return sort.Search(len(imap), func(i int) bool {
		return imap[i] >= key
	})
}

type Language uint16

// getLangID returns the langID of s if s is a canonical subtag
// or langUnknown if s is not a canonical subtag.
func getLangID(s []byte) (Language, error) {
	if len(s) == 2 {
		return getLangISO2(s)
	}
	return getLangISO3(s)
}

	t.LangID, e = getLangID(scan.token)
	scan.setError(e)
	scan.replace(t.LangID.String())
	langStart := scan.start
	end = scan.scan()
	for len(scan.token) == 3 && isAlpha(scan.token[0]) {
		// From http://tools.ietf.org/html/bcp47, <lang>-<extlang> tags are equivalent
		// to a tag of the form <extlang>.
		if doNorm {
			lang, e := getLangID(scan.token)
			if lang != 0 {
				t.LangID = lang

	defer func() {
		if recover() != nil {
			l = 0
			err = ErrSyntax
		}
	}()

	if n := len(s); n < 2 || 3 < n {
		return 0, ErrSyntax
	}
	var buf [3]byte
	return getLangID(buf[:copy(buf[:], s)])
}

// ParseScript parses a 4-letter ISO 15924 code.
// It returns a ValueError if s is a well-formed but unknown script identifier
// or another error if another error occurred.