// 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
}
// XXX: needs to be fixed
private void update_iterator()
{
switch (_axis)
{
case Type.NONE:
if (node_test() is AttributeTest)
{
_iterator = new AttributeAxis();
}
else
{
_iterator = new ChildAxis();
}
break;
case Type.CHILD:
_iterator = new ChildAxis();
break;
case Type.DESCENDANT:
_iterator = new DescendantAxis();
break;
case Type.FOLLOWING_SIBLING:
_iterator = new FollowingSiblingAxis();
break;
case Type.FOLLOWING:
_iterator = new FollowingAxis();
break;
case Type.AT_SYM:
case Type.ATTRIBUTE:
_iterator = new AttributeAxis();
break;
case Type.SELF:
_iterator = new SelfAxis();
break;
case Type.DESCENDANT_OR_SELF:
_iterator = new DescendantOrSelfAxis();
break;
case Type.NAMESPACE:
throw new StaticError("XPST0010", "namespace axis not implemented");
default:
Debug.Assert(false);
break;
}
}
// instructor
public AxisStack(ForwardAxis faxis, ActiveAxis parent)
{
_subtree = faxis;
_stack = new ArrayList();
_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
}
