public static bool IsRegion(string s)
{
// region = 2ALPHA ; ISO 3166-1 code
// / 3DIGIT ; UN M.49 code
return(((s.Length == 2) && AsciiUtil.IsAlphaString(s)) ||
((s.Length == 3) && AsciiUtil.IsNumericString(s)));
}
//
// Language subtag syntax checking methods
//
public static bool 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
return((s.Length >= 2) && (s.Length <= 8) && AsciiUtil.IsAlphaString(s));
}
public static bool 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) &&
AsciiUtil.IsAlphaString(s) &&
!AsciiUtil.CaseIgnoreMatch(PRIVATEUSE, s));
}
public static bool IsScript(String s)
{
// script = 4ALPHA ; ISO 15924 code
return((s.Length == 4) && AsciiUtil.IsAlphaString(s));
}
public static bool IsExtlang(string s)
{
// extlang = 3ALPHA ; selected ISO 639 codes
// *2("-" 3ALPHA) ; permanently reserved
return((s.Length == 3) && AsciiUtil.IsAlphaString(s));
}