/** * 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()); }