public bool MoveNext()
{
if (!_navStack.IsEmpty)
{
while (true)
{
// Move to the next matching node that is before the top node on the stack in document order
if (_filter.MoveToFollowing(_navCurrent, _navStack.Peek()))
{
// Found match
return(true);
}
// Do not include ancestor nodes as part of the preceding axis
_navCurrent.MoveTo(_navStack.Pop());
// No more preceding matches possible
if (_navStack.IsEmpty)
{
break;
}
}
}
return(false);
}
public IteratorResult MoveNext(XPathNavigator input)
{
switch (_state)
{
case IteratorState.NeedCandidateCurrent:
// If there are no more input nodes, then iteration is complete
if (input == null)
{
return(IteratorResult.NoMoreNodes);
}
// Save input node as current node
_navCurrent = XmlQueryRuntime.SyncToNavigator(_navCurrent, input);
// Scan for additional input nodes within the same document (since they are after navCurrent in docorder)
_state = IteratorState.HaveCandidateCurrent;
return(IteratorResult.NeedInputNode);
case IteratorState.HaveCandidateCurrent:
// If there are no more input nodes,
if (input == null)
{
// Then candidate node has been selected, and there are no further input nodes
_state = IteratorState.HaveCurrentNoNext;
}
else
{
// If the input node is in the same document as the current node,
if (_navCurrent.ComparePosition(input) != XmlNodeOrder.Unknown)
{
// Then update the current node and get the next input node
_navCurrent = XmlQueryRuntime.SyncToNavigator(_navCurrent, input);
return(IteratorResult.NeedInputNode);
}
// Save the input node as navNext
_navNext = XmlQueryRuntime.SyncToNavigator(_navNext, input);
_state = IteratorState.HaveCurrentHaveNext;
}
PushAncestors();
break;
}
if (!_navStack.IsEmpty)
{
while (true)
{
// Move to the next matching node that is before the top node on the stack in document order
if (_filter.MoveToFollowing(_navCurrent, _navStack.Peek()))
{
// Found match
return(IteratorResult.HaveCurrentNode);
}
// Do not include ancestor nodes as part of the preceding axis
_navCurrent.MoveTo(_navStack.Pop());
// No more preceding matches possible
if (_navStack.IsEmpty)
{
break;
}
}
}
if (_state == IteratorState.HaveCurrentNoNext)
{
// No more nodes, so iteration is complete
_state = IteratorState.NeedCandidateCurrent;
return(IteratorResult.NoMoreNodes);
}
// Make next node the current node and start trying to find input node greatest in docorder
_navCurrent = XmlQueryRuntime.SyncToNavigator(_navCurrent, _navNext);
_state = IteratorState.HaveCandidateCurrent;
return(IteratorResult.HaveCurrentNode);
}
