// instructor
public AxisStack(ForwardAxis faxis, ActiveAxis parent)
{
this.subtree = faxis;
this.stack = new ArrayList();
this.parent = parent; // need to use its contextdepth each time....
// improvement:
// if ! isDss, there has nothing to do with Push/Pop, only one copy each time will be kept
// if isDss, push and pop each time....
if (!faxis.IsDss) // keep an instance
{
this.Push(1); // context depth + 1
}
// else just keep stack empty
}
// equal & ! attribute then move
// "a/b/c" pointer from a move to b
// return true if reach c and c is an element and c is the axis
internal bool MoveToChild(string name, string URN, int depth, ForwardAxis parent)
{
// an attribute can never be the same as an element
if (Asttree.IsAttribute(this.curNode))
{
return(false);
}
// either moveToParent or moveToChild status will have to be changed into unmatch...
if (this.isMatch)
{
this.isMatch = false;
}
if (!AxisStack.Equal(this.curNode.Name, this.curNode.URN, name, URN))
{
return(false);
}
if (this.curDepth == -1)
{
SetDepth(depth);
}
else if (depth > this.curDepth)
{
return(false);
}
// matched ...
if (this.curNode == parent.TopNode)
{
this.isMatch = true;
return(true);
}
// move down this.curNode
DoubleLinkAxis nowNode = (DoubleLinkAxis)(this.curNode.Next);
if (Asttree.IsAttribute(nowNode))
{
this.isMatch = true; // for attribute
return(false);
}
this.curNode = nowNode;
this.curDepth++;
return(false);
}
// "a/b/c" pointer from b move to a
// needn't change even tree structure changes
internal void MoveToParent(int depth, ForwardAxis parent)
{
// "a/b/c", trying to match b (current node), but meet the end of a, so move pointer to a
if (depth == this.curDepth - 1)
{
// really need to move the current node pointer to parent
// what i did here is for seperating the case of IsDss or only IsChild
// bcoz in the first case i need to expect "a" from random depth
// -1 means it doesn't expect some specific depth (referecing the dealing to -1 in movetochild method
// while in the second case i can't change the root depth which is 1.
if ((this.curNode.Input == parent.RootNode) && (parent.IsDss))
{
this.curNode = parent.RootNode;
this.rootDepth = this.curDepth = -1;
return;
}
else if (this.curNode.Input != null) // else cur-depth --, cur-node change
{
this.curNode = (DoubleLinkAxis)(this.curNode.Input);
this.curDepth--;
return;
}
else
{
return;
}
}
// "a/b/c", trying to match b (current node), but meet the end of x (another child of a)
// or maybe i matched, now move out the current node
// or move out after failing to match attribute
// the node i m next expecting is still the current node
else if (depth == this.curDepth) // after matched or [2] failed in matching attribute
{
if (this.isMatch)
{
this.isMatch = false;
}
}
return; // this node is still what i am expecting
// ignore
}