public static bool IsVariant(string s)
{
// variant = 5*8alphanum ; registered variants
// / (DIGIT 3alphanum)
int len = s.Length;
if (len >= 5 && len <= 8)
{
return(AsciiUtil.IsAlphaNumericString(s));
}
if (len == 4)
{
return(AsciiUtil.IsNumeric(s[0]) &&
AsciiUtil.IsAlphaNumeric(s[1]) &&
AsciiUtil.IsAlphaNumeric(s[2]) &&
AsciiUtil.IsAlphaNumeric(s[3]));
}
return(false);
}
public static bool IsTypeSubtag(string s)
{
// 3*8alphanum
return((s.Length >= 3) && (s.Length <= 8) && AsciiUtil.IsAlphaNumeric(s));
}
public static bool IsKey(string s)
{
// 2alphanum
return((s.Length == 2) && AsciiUtil.IsAlphaNumeric(s));
}
public static bool IsPrivateuseSubtag(string s)
{
// privateuse = "x" 1*("-" (1*8alphanum))
return((s.Length >= 1) && (s.Length <= 8) && AsciiUtil.IsAlphaNumeric(s));
}
public static bool IsExtensionSubtag(string s)
{
// extension = singleton 1*("-" (2*8alphanum))
return((s.Length >= 2) && (s.Length <= 8) && AsciiUtil.IsAlphaNumeric(s));
}