/**
* The basic method for splitting off a clause of a tree. This modifies the tree in place.
*
* @param tree The tree to split a clause from.
* @param toKeep The edge representing the clause to keep.
*/
static void splitToChildOfEdge(SemanticGraph tree, SemanticGraphEdge toKeep) {
Queue<IndexedWord> fringe = new LinkedList<>();
List<IndexedWord> nodesToRemove = new ArrayList<>();
// Find nodes to remove
// (from the root)
for (IndexedWord root : tree.getRoots()) {
nodesToRemove.add(root);
for (SemanticGraphEdge out : tree.outgoingEdgeIterable(root)) {
if (!out.equals(toKeep)) {
fringe.add(out.getDependent());
}
}
}
// (recursively)
while (!fringe.isEmpty()) {
IndexedWord node = fringe.poll();
nodesToRemove.add(node);
for (SemanticGraphEdge out : tree.outgoingEdgeIterable(node)) {
if (!out.equals(toKeep)) {
fringe.add(out.getDependent());
}
}
}
// Remove nodes
nodesToRemove.forEach(tree::removeVertex);
// Set new root
tree.setRoot(toKeep.getDependent());
}
