public override object visit(XPathExpr e)
{
if (e.slashes() > 0)
{
throw new XPathParserException("Access to root node is not allowed (set by caller)");
}
do
{
e.expr().accept(this); // check the single step (may have filter with root access)
e = e.next(); // follow singly linked list of the path, it's all relative past the first one
} while (e != null);
return(null);
}
/// <summary>
/// Validate an xpath expression.
/// </summary>
/// <param name="e">
/// is the expression. </param>
/// <returns> null. </returns>
public virtual object visit(XPathExpr e)
{
XPathExpr xp = e;
bool firstStep = true;
while (xp != null)
{
if (firstStep && xp.slashes() != 0)
{
_rootUsed = true;
}
firstStep = false;
StepExpr se = xp.expr();
if (se != null)
{
se.accept(this);
}
xp = xp.next();
}
return(null);
}
/// <param name="e">
/// is the xpath expression. </param>
/// <returns> result. </returns>
public virtual object visit(XPathExpr e)
{
XPathExpr xp = e;
int depth = 0; // indicates how many / we traversed
XPathExpr result = e;
while (xp != null)
{
int slashes = xp.slashes();
StepExpr se = xp.expr();
if (slashes == 1)
{
// this is a single slash and nothing else...
if (se == null)
{
return(make_root_self_node());
}
// /RelativePathExpr
if (depth == 0)
{
XPathExpr xpe = make_root_self_node();
xpe.set_next(e);
result = xpe;
}
}
if (slashes == 2)
{
// //RelativePathExpr
if (depth == 0)
{
XPathExpr desc = make_descendant_or_self();
desc.set_slashes(1);
e.set_slashes(1);
desc.set_next(e);
XPathExpr root_self = make_root_self_node();
root_self.set_next(desc);
return(root_self);
}
}
if (se != null)
{
se.accept(this);
}
XPathExpr next = xp.next();
// peek if the next guy will have 2 slashes...
if (next != null)
{
// StepExpr//StepExpr
if (next.slashes() == 2)
{
// create the node to stick between the
// slashes
XPathExpr desc = make_descendant_or_self();
desc.set_slashes(1);
// current node / desc / next
xp.set_next(desc);
desc.set_next(next);
next.set_slashes(1);
}
}
xp = next;
depth++;
}
return(result);
}