public Success(string value, ParserString remaining)
{
Value = value;
CharsConsumed = 1;
Remaining = remaining;
IsSuccess = true;
}
public Success(string value, ParserString remaining, int charsConsumed) : this(value, remaining)
{
if (charsConsumed < 0)
{
throw new ArgumentException("The number of characters must be greater than or equal to zero");
}
CharsConsumed = charsConsumed;
}
public static bool TryMatchExpr(ParserString parserString, out RegexTerm expr, out ParserString newParserString)
{
level++;
expr = null;
newParserString = null;
char c;
bool doneMatching;
while (parserString.HasNext())
{
doneMatching = false;
c = parserString.Head;
if (Char.IsWhiteSpace(c))
{
parserString = parserString.Advance(1);
continue;
}
// Match nested expr.
if (c == '(') // Match expr nested in ().
{
if (!parserString.NextContains(')'))
{
return(false);
}
parserString = parserString.Advance(1);
RegexTermGroup innerTerms = new RegexTermGroup();
while (TryMatchExpr(parserString, out RegexTerm innerTerm, out ParserString afterInnerTermString)) // Hopefully this consumes everything up to ')'.
{
innerTerms.Terms.Add(innerTerm);
parserString = afterInnerTermString;
}
// Empty () is valid. It just won't do anything.
while (parserString.HasNext()) // Loop over whitespace.
{
c = parserString.Head;
if (Char.IsWhiteSpace(c)) // Skip whitespace.
{
parserString = parserString.Advance(1);
continue;
}
if (c == ')')
{ // Might need to check for whitespace before quantifier.
parserString = parserString.Advance(1);
if (TryMatchQuantifier(parserString, out Quantifier quantifier, out ParserString afterQuantifierString))
{
quantifier.SetTerm(innerTerms);
expr = quantifier;
parserString = afterQuantifierString;
}
else
{
expr = innerTerms;
parserString = parserString.Advance(1); // Consume ')'.
}
doneMatching = true;
}
else // No matching ')' after a token or token and a quantifier.
{
return(false);
}
}
if (!doneMatching)
{
return(false);
}
}