/** Is tag reachable from node on paths with no visited nodes? */
private Node reachesTag(Node node, UniqueTag tag, Set<Node> visited) {
assert (node.isRep());
if (visited.contains(node)) return null;
if (tag.mergeable(node.tag)) return node;
visited.add(node);
if (secondary_index[2]) {
for (Field f : node.infields.keySet())
for (FieldEdge e : node.infields.get(f)) {
assert (e.dst == node);
Node result = reachesTag(e.src.getRep(), tag, visited);
if (result != null) return result;
}
} else {
for (Field f : fedges.keySet())
for (FieldEdge e : fedges.get(f)) {
if (e.dst != node) continue;
Node result = reachesTag(e.src, tag, visited);
if (result != null) return result;
}
}
return null;
}
/** Does the graph contain a node of a given tag? */
private Node containsTag(UniqueTag tag) {
for (Node node : nodes) if (node.isRep() && tag.mergeable(node.tag)) return node;
return null;
}