public static boolean isLanguage(String s) {
// language = 2*3ALPHA ; shortest ISO 639 code
// ["-" extlang] ; sometimes followed by
// ; extended language subtags
// / 4ALPHA ; or reserved for future use
// / 5*8ALPHA ; or registered language subtag
int len = s.length();
return (len >= 2) && (len <= 8) && LocaleUtils.isAlphaString(s);
}
public static boolean isExtensionSingleton(String s) {
// singleton = DIGIT ; 0 - 9
// / %x41-57 ; A - W
// / %x59-5A ; Y - Z
// / %x61-77 ; a - w
// / %x79-7A ; y - z
return (s.length() == 1)
&& LocaleUtils.isAlphaString(s)
&& !LocaleUtils.caseIgnoreMatch(PRIVATEUSE, s);
}
public static boolean isRegion(String s) {
// region = 2ALPHA ; ISO 3166-1 code
// / 3DIGIT ; UN M.49 code
return ((s.length() == 2) && LocaleUtils.isAlphaString(s))
|| ((s.length() == 3) && LocaleUtils.isNumericString(s));
}
public static boolean isScript(String s) {
// script = 4ALPHA ; ISO 15924 code
return (s.length() == 4) && LocaleUtils.isAlphaString(s);
}
public static boolean isExtlang(String s) {
// extlang = 3ALPHA ; selected ISO 639 codes
// *2("-" 3ALPHA) ; permanently reserved
return (s.length() == 3) && LocaleUtils.isAlphaString(s);
}
