/**
* Returns all summary path nodes for the specified location step or {@code null} if nodes cannot
* be retrieved or are found on different levels.
*
* @param data data reference
* @param last last step to be checked
* @return path nodes
*/
private ArrayList<PathNode> pathNodes(final Data data, final int last) {
// skip request if no path index exists or might be out-of-date
if (!data.meta.uptodate) return null;
ArrayList<PathNode> nodes = data.paths.root();
for (int s = 0; s <= last; s++) {
// only follow axis steps
final Step curr = axisStep(s);
if (curr == null) return null;
final boolean desc = curr.axis == DESC;
if (!desc && curr.axis != CHILD || curr.test.kind != Kind.NAME) return null;
final int name = data.elemNames.id(curr.test.name.local());
final ArrayList<PathNode> tmp = new ArrayList<>();
for (final PathNode node : PathSummary.desc(nodes, desc)) {
if (node.kind == Data.ELEM && name == node.name) {
// skip test if an element name occurs on different levels
if (!tmp.isEmpty() && tmp.get(0).level() != node.level()) return null;
tmp.add(node);
}
}
if (tmp.isEmpty()) return null;
nodes = tmp;
}
return nodes;
}
/**
* Returns all summary path nodes for the specified location step or {@code null} if nodes cannot
* be retrieved or are found on different levels.
*
* @param data data reference
* @param l last step to be checked
* @return path nodes
*/
ArrayList<PathNode> pathNodes(final Data data, final int l) {
// skip request if no path index exists or might be out-of-date
if (!data.meta.uptodate) return null;
ArrayList<PathNode> in = data.paths.root();
for (int s = 0; s <= l; ++s) {
final Step curr = axisStep(s);
if (curr == null) return null;
final boolean desc = curr.axis == DESC;
if (!desc && curr.axis != CHILD || curr.test.mode != Mode.LN) return null;
final int name = data.tagindex.id(curr.test.name.local());
final ArrayList<PathNode> al = new ArrayList<>();
for (final PathNode pn : PathSummary.desc(in, desc)) {
if (pn.kind == Data.ELEM && name == pn.name) {
// skip test if a tag is found on different levels
if (!al.isEmpty() && al.get(0).level() != pn.level()) return null;
al.add(pn);
}
}
if (al.isEmpty()) return null;
in = al;
}
return in;
}