public void Accept(IAstNodeReplacement visitor)
{
visitor.VisitEnter(this);
foreach (AstNode node in Children)
{
node.Accept(visitor);
}
visitor.VisitLeave(this);
}
public override void VisitLeave(CapturingGroup expression)
{
String name = expression.Name;
Boolean reduceBySingleChildNode = expression.DoReplaceBySingleChildNode;
IsMatchPredicate local = _matchStack.Pop();
_matchStack.Push(
delegate(IInputIterator iterator)
{
if (expression.DoCreateCustomAstNode && _astNodeFactory == null)
{
throw new ArgumentNullException("Second constructor overload is required during instantiation. astNodeFactory requires to be set with this parser implementation.");
}
Int32 savePosition = iterator.Index;
_sandbox.Peek().Push(new AstNode());
if (local(iterator))
{
// predicates being processed should not append ast
if (_disableCapturingGroup.Count > 0)
{
_sandbox.Peek().Pop();
iterator.Index = savePosition;
return(true);
}
if (savePosition >= iterator.Index)
{
// Warn terminal does not consume and ast should not be created for it, yet it should return that it was successful match.
_sandbox.Peek().Pop();
iterator.Index = savePosition;
return(true);
}
Byte[] matchedBytes = iterator.Text(savePosition, iterator.Index - 1);
if (_xmlBackReferenceLookup.ContainsKey(name))
{
_xmlBackReferenceLookup[name].Push(matchedBytes);
}
else
{
_xmlBackReferenceLookup.Add(name, new Stack <Byte[]>());
_xmlBackReferenceLookup[name].Push(matchedBytes);
}
AstNode node = _sandbox.Peek().Pop();
node.Token = new TokenMatch(name, savePosition, iterator.Index - 1);
if (expression.DoCreateCustomAstNode)
{
// create a custom astnode
IAstNodeReplacement nodevisitor = _astNodeFactory.Create(node);
nodevisitor.Token = node.Token;
nodevisitor.Parent = node.Parent;
nodevisitor.Children = node.Children;
foreach (AstNode updateparent in nodevisitor.Children)
{
updateparent.Parent = nodevisitor;
}
// since the whole tree has not finished completing this.Parent will be null on this run.
// logic inside astnodereplacement is to create properties, business names, that internally check Children collection to mine data.
// you still will need a top level visitor to process tree after it completely available.
node.Accept(nodevisitor);
node = nodevisitor;
}
if (reduceBySingleChildNode)
{
if (node.Children.Count == 1)
{
node = node.Children[0];
}
}
if (_sandbox.Peek().Count > 0)
{
node.Parent = _sandbox.Peek().Peek();
_sandbox.Peek().Peek().Children.Add(node);
}
else
{
_sandbox.Peek().Push(node);
// don't loose the root node
// each successful sandbox will have 1 item left in the stack
}
return(true);
}
_sandbox.Peek().Pop();
iterator.Index = savePosition;
return(false);
});
}
