private static bool IsDomainStart(char c, bool allowInternational, out SubDomainType type)
{
if (c < 128)
{
if (IsLetter(c))
{
type = SubDomainType.Alphabetic;
return(true);
}
if (IsDigit(c))
{
type = SubDomainType.Numeric;
return(true);
}
type = SubDomainType.None;
return(false);
}
if (allowInternational)
{
type = SubDomainType.Alphabetic;
return(true);
}
type = SubDomainType.None;
return(false);
}
private static bool IsDomain(char c, bool allowInternational, ref SubDomainType type)
{
if (c < 128)
{
if (IsLetter(c) || c == '-')
{
type |= SubDomainType.Alphabetic;
return(true);
}
if (IsDigit(c))
{
type |= SubDomainType.Numeric;
return(true);
}
return(false);
}
if (allowInternational)
{
type |= SubDomainType.Alphabetic;
return(true);
}
return(false);
}
private static bool SkipSubDomain(string text, ref int index, bool allowInternational, out SubDomainType type)
{
var startIndex = index;
if (!IsDomainStart(text[index], allowInternational, out type))
{
return(false);
}
index++;
while (index < text.Length && IsDomain(text[index], allowInternational, ref type))
{
index++;
}
return(index - startIndex < 64 && text[index - 1] != '-');
}
static bool SkipSubDomain(string text, ref int index, bool allowInternational, out SubDomainType type)
{
int startIndex = index;
if (!IsDomainStart(text[index], allowInternational, out type))
{
return(false);
}
index++;
while (index < text.Length && IsDomain(text[index], allowInternational, ref type))
{
index++;
}
// Don't allow single-character top-level domains.
if (index == text.Length && (index - startIndex) == 1)
{
return(false);
}
return((index - startIndex) <= 64 && text[index - 1] != '-');
}
