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 isPrivateusePrefixChar(char c) {
return (LocaleUtils.caseIgnoreMatch(PRIVATEUSE, String.valueOf(c)));
}
public static boolean isPrivateusePrefix(String s) {
// privateuse = "x" 1*("-" (1*8alphanum))
return (s.length() == 1) && LocaleUtils.caseIgnoreMatch(PRIVATEUSE, s);
}
