public static Token Parse(string s, CultureInfo cultureInfo)
{
if (string.IsNullOrEmpty(s))
{
return(new NullToken());
}
int length = s.Length;
int startingPos = 0;
return(ParseUnion(ref startingPos, false).Optimize());
Token ParseUnion(ref int pos, bool mustClose)
{
UnionToken unionToken = new UnionToken();
ConcatenationToken concatenationToken = null;
int startpos = pos;
bool closed = false;
while (pos < length)
{
Token token = null;
if (TryMatchCharacter(ref pos, Token.GroupBegin))
{
// parse group
token = ParseUnion(ref pos, true);
}
else if (mustClose && TryMatchCharacter(ref pos, Token.GroupEnd))
{
closed = true;
break;
}
else if (TryMatchCharacter(ref pos, Token.GroupSeparator))
{
unionToken.Tokens.Add(concatenationToken as Token ?? new NullToken());
concatenationToken = null;
continue;
}
else if (TryMatchCharacter(ref pos, Token.RangeBegin))
{
// parse range
token = ParseRange(ref pos);
}
else if (TryParseCharacterClass(ref pos, out string characters))
{
token = new CharsetToken(characters);
}
int savedpos = pos;
if (TryParseQuantifier(ref pos, out int minlen, out int maxlen))
{
if (token == null)
{
throw new ArgumentException(string.Format(
CultureInfo.InvariantCulture,
Properties.Resources.E_InvalidRegex_TokenNotQuantifiable,
s,
savedpos));
}
token.MinCount = minlen;
token.MaxCount = maxlen;
}
public IParseFunction Visit(UnionToken target) => VisitUnion(target.Union, isMemoized, model);
protected override IParseResult TryGetTokenWithoutNullCheck(IStringStream inputStream, out IToken token)
{
inputStream.Pop();
token = new UnionToken(_initialStreamPosition);
return(new SuccessParseResult());
}
