/// <summary>
/// Parses a Group who's children are part of a chain and do not alternate
/// </summary>
/// <param name="group"></param>
/// <param name="token"></param>
/// <returns></returns>
public TokenParseResult ParseRule(Grouping group, Token startToken, ParserSettings settings)
{
List <SyntaxNode> nodes = new List <SyntaxNode>();
TokenParseResult groupResult = TokenParseResult.Failed(startToken);
TokenParseResult ruleResult;
int ruleIdx;
Rule rule;
Token token;
// got the minimum results and wasn't an exception
bool lastRuleOK;
List <SyntaxNode> ruleNodes = new List <SyntaxNode>();
ruleIdx = 0;
token = startToken;
lastRuleOK = true;
while (lastRuleOK && ruleIdx < group.Count && token != null)
{
// every rule has its own scope
rule = group[ruleIdx];
ruleNodes.Clear();
lastRuleOK = false;
while (token != null)
{
if (ruleResult = rule.Parse(token, settings))
{
ruleNodes.Add(ruleResult);
token = ruleResult.NextToken;
if (ruleNodes.Count >= rule.Quantifier.MaxValue)
{
break;
}
}
else
{
break;
}
}
lastRuleOK = (rule.Quantifier.MinValue <= ruleNodes.Count) ^ rule.IsException;
// if we achieved min qty then add to nodes.
if (lastRuleOK)
{
nodes.AddRange(ruleNodes);
ruleIdx++;
}
}
if (lastRuleOK && ruleIdx >= group.LastRequiredRuleIndex && nodes.Count > 0)
{
SyntaxNode parent = new SyntaxNode(group, startToken);
parent.AddRange(nodes);
// token should be set to the last succesful nextToken
groupResult = TokenParseResult.Success(parent, token);
}
return(groupResult);
}
