private RegexTerm VisitRegexTermNode(IInternalTreeNode internalNode)
{
RegexFactor factor = null;
RegexTerm term = null;
for (var c = 0; c < internalNode.Children.Count; c++)
{
var child = internalNode.Children[c];
if (child.NodeType != TreeNodeType.Internal)
{
continue;
}
var childInternalNode = child as IInternalTreeNode;
var childInternalNodeSymbolValue = childInternalNode.Symbol.Value;
if (RegexGrammar.Factor == childInternalNodeSymbolValue)
{
factor = VisitRegexFactorNode(childInternalNode);
}
else if (RegexGrammar.Term == childInternalNodeSymbolValue)
{
term = VisitRegexTermNode(childInternalNode);
}
}
if (term is null)
{
return(new RegexTerm(factor));
}
return(new RegexTermFactor(factor, term));
}
private static INfa Factor(RegexFactor factor)
{
var atomNfa = Atom(factor.Atom);
switch (factor.NodeType)
{
case RegexNodeType.RegexFactor:
return(atomNfa);
case RegexNodeType.RegexFactorIterator:
var regexFactorIterator = factor as RegexFactorIterator;
switch (regexFactorIterator.Iterator)
{
case RegexIterator.ZeroOrMany:
return(KleeneStar(atomNfa));
case RegexIterator.OneOrMany:
return(KleenePlus(atomNfa));
case RegexIterator.ZeroOrOne:
return(Optional(atomNfa));
}
break;
}
throw new InvalidOperationException("Unrecognized regex factor");
}
public RegexTermFactor(RegexFactor factor, RegexTerm term)
: base(factor)
{
Term = term;
_hashCode = ComputeHashCode();
}
public RegexTerm(RegexFactor factor)
{
Factor = factor;
_hashCode = ComputeHashCode();
}