/**
* 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());
}
/**
* Strip away case edges, if the incoming edge is a preposition. This replicates the behavior of
* the old Stanford dependencies on universal dependencies.
*
* @param tree The tree to modify in place.
*/
public static void stripPrepCases(SemanticGraph tree) {
// Find incoming case edges that have an 'nmod' incoming edge
List<SemanticGraphEdge> toClean = new ArrayList<>();
for (SemanticGraphEdge edge : tree.edgeIterable()) {
if ("case".equals(edge.getRelation().toString())) {
boolean isPrepTarget = false;
for (SemanticGraphEdge incoming : tree.incomingEdgeIterable(edge.getGovernor())) {
if ("nmod".equals(incoming.getRelation().getShortName())) {
isPrepTarget = true;
break;
}
}
if (isPrepTarget && !tree.outgoingEdgeIterator(edge.getDependent()).hasNext()) {
toClean.add(edge);
}
}
}
// Delete these edges
for (SemanticGraphEdge edge : toClean) {
tree.removeEdge(edge);
tree.removeVertex(edge.getDependent());
assert isTree(tree);
}
}
/**
* Stips aux and mark edges when we are splitting into a clause.
*
* @param toModify The tree we are stripping the edges from.
*/
private void stripAuxMark(SemanticGraph toModify) {
List<SemanticGraphEdge> toClean = new ArrayList<>();
for (SemanticGraphEdge edge : toModify.outgoingEdgeIterable(toModify.getFirstRoot())) {
String rel = edge.getRelation().toString();
if (("aux".equals(rel) || "mark".equals(rel))
&& !toModify.outgoingEdgeIterator(edge.getDependent()).hasNext()) {
toClean.add(edge);
}
}
for (SemanticGraphEdge edge : toClean) {
toModify.removeEdge(edge);
toModify.removeVertex(edge.getDependent());
}
}
public static DependencyParse parse(String text) {
if (pipeline == null) {
loadModels();
}
DependencyParse parse = new DependencyParse();
Annotation document = new Annotation(text);
pipeline.annotate(document);
List<CoreMap> sentences = document.get(SentencesAnnotation.class);
for (CoreMap sentence : sentences) {
SemanticGraph dependencies = sentence.get(CollapsedCCProcessedDependenciesAnnotation.class);
IndexedWord root = dependencies.getFirstRoot();
parse.setHeadNode(root.index());
List<SemanticGraphEdge> edges = dependencies.edgeListSorted();
// System.out.println(edges);
for (SemanticGraphEdge t : edges) {
String dep = t.getDependent().originalText();
int depIndex = t.getDependent().index();
String depPOS = t.getDependent().tag();
int depStart = t.getDependent().beginPosition();
int depEnd = t.getDependent().endPosition();
String gov = t.getGovernor().originalText();
int govIndex = t.getGovernor().index();
String govPOS = t.getGovernor().tag();
int govStart = t.getGovernor().beginPosition();
int govEnd = t.getGovernor().endPosition();
parse.addNode(govIndex, gov, govPOS, govStart, govEnd);
parse.addNode(depIndex, dep, depPOS, depStart, depEnd);
parse.addEdge(depIndex, govIndex, t.getRelation().getShortName());
}
}
return parse;
}
/**
* Create a searcher manually, suppling a dependency tree, an optional classifier for when to
* split clauses, and a featurizer for that classifier. You almost certainly want to use {@link
* ClauseSplitter#load(String)} instead of this constructor.
*
* @param tree The dependency tree to search over.
* @param assumedTruth The assumed truth of the tree (relevant for natural logic inference). If in
* doubt, pass in true.
* @param isClauseClassifier The classifier for whether a given dependency arc should be a new
* clause. If this is not given, all arcs are treated as clause separators.
* @param featurizer The featurizer for the classifier. If no featurizer is given, one should be
* given in {@link ClauseSplitterSearchProblem#search(java.util.function.Predicate,
* Classifier, Map, java.util.function.Function, int)}, or else the classifier will be
* useless.
* @see ClauseSplitter#load(String)
*/
protected ClauseSplitterSearchProblem(
SemanticGraph tree,
boolean assumedTruth,
Optional<Classifier<ClauseSplitter.ClauseClassifierLabel, String>> isClauseClassifier,
Optional<
Function<
Triple<
ClauseSplitterSearchProblem.State,
ClauseSplitterSearchProblem.Action,
ClauseSplitterSearchProblem.State>,
Counter<String>>>
featurizer) {
this.tree = new SemanticGraph(tree);
this.assumedTruth = assumedTruth;
this.isClauseClassifier = isClauseClassifier;
this.featurizer = featurizer;
// Index edges
this.tree.edgeIterable().forEach(edgeToIndex::addToIndex);
// Get length
List<IndexedWord> sortedVertices = tree.vertexListSorted();
sentenceLength = sortedVertices.get(sortedVertices.size() - 1).index();
// Register extra edges
for (IndexedWord vertex : sortedVertices) {
extraEdgesByGovernor.put(vertex, new ArrayList<>());
extraEdgesByDependent.put(vertex, new ArrayList<>());
}
List<SemanticGraphEdge> extraEdges = Util.cleanTree(this.tree);
assert Util.isTree(this.tree);
for (SemanticGraphEdge edge : extraEdges) {
extraEdgesByGovernor.get(edge.getGovernor()).add(edge);
extraEdgesByDependent.get(edge.getDependent()).add(edge);
}
}
/**
* A little utility function to make sure a SemanticGraph is a tree.
*
* @param tree The tree to check.
* @return True if this {@link edu.stanford.nlp.semgraph.SemanticGraph} is a tree (versus a DAG,
* or Graph).
*/
public static boolean isTree(SemanticGraph tree) {
for (IndexedWord vertex : tree.vertexSet()) {
// Check one and only one incoming edge
if (tree.getRoots().contains(vertex)) {
if (tree.incomingEdgeIterator(vertex).hasNext()) {
return false;
}
} else {
Iterator<SemanticGraphEdge> iter = tree.incomingEdgeIterator(vertex);
if (!iter.hasNext()) {
return false;
}
iter.next();
if (iter.hasNext()) {
return false;
}
}
// Check incoming and outgoing edges match
for (SemanticGraphEdge edge : tree.outgoingEdgeIterable(vertex)) {
boolean foundReverse = false;
for (SemanticGraphEdge reverse : tree.incomingEdgeIterable(edge.getDependent())) {
if (reverse == edge) {
foundReverse = true;
}
}
if (!foundReverse) {
return false;
}
}
for (SemanticGraphEdge edge : tree.incomingEdgeIterable(vertex)) {
boolean foundReverse = false;
for (SemanticGraphEdge reverse : tree.outgoingEdgeIterable(edge.getGovernor())) {
if (reverse == edge) {
foundReverse = true;
}
}
if (!foundReverse) {
return false;
}
}
}
// Check for cycles
if (isCyclic(tree)) {
return false;
}
// Check topological sort -- sometimes fails?
// try {
// tree.topologicalSort();
// } catch (Exception e) {
// e.printStackTrace();
// return false;
// }
return true;
}
@Override
public void process(JCas jCas) throws AnalysisEngineProcessException {
Annotation document = this.processor.process(jCas.getDocumentText());
String lastNETag = "O";
int lastNEBegin = -1;
int lastNEEnd = -1;
for (CoreMap tokenAnn : document.get(TokensAnnotation.class)) {
// create the token annotation
int begin = tokenAnn.get(CharacterOffsetBeginAnnotation.class);
int end = tokenAnn.get(CharacterOffsetEndAnnotation.class);
String pos = tokenAnn.get(PartOfSpeechAnnotation.class);
String lemma = tokenAnn.get(LemmaAnnotation.class);
Token token = new Token(jCas, begin, end);
token.setPos(pos);
token.setLemma(lemma);
token.addToIndexes();
// hackery to convert token-level named entity tag into phrase-level tag
String neTag = tokenAnn.get(NamedEntityTagAnnotation.class);
if (neTag.equals("O") && !lastNETag.equals("O")) {
NamedEntityMention ne = new NamedEntityMention(jCas, lastNEBegin, lastNEEnd);
ne.setMentionType(lastNETag);
ne.addToIndexes();
} else {
if (lastNETag.equals("O")) {
lastNEBegin = begin;
} else if (lastNETag.equals(neTag)) {
// do nothing - begin was already set
} else {
NamedEntityMention ne = new NamedEntityMention(jCas, lastNEBegin, lastNEEnd);
ne.setMentionType(lastNETag);
ne.addToIndexes();
lastNEBegin = begin;
}
lastNEEnd = end;
}
lastNETag = neTag;
}
if (!lastNETag.equals("O")) {
NamedEntityMention ne = new NamedEntityMention(jCas, lastNEBegin, lastNEEnd);
ne.setMentionType(lastNETag);
ne.addToIndexes();
}
// add sentences and trees
for (CoreMap sentenceAnn : document.get(SentencesAnnotation.class)) {
// add the sentence annotation
int sentBegin = sentenceAnn.get(CharacterOffsetBeginAnnotation.class);
int sentEnd = sentenceAnn.get(CharacterOffsetEndAnnotation.class);
Sentence sentence = new Sentence(jCas, sentBegin, sentEnd);
sentence.addToIndexes();
// add the syntactic tree annotation
List<CoreLabel> tokenAnns = sentenceAnn.get(TokensAnnotation.class);
Tree tree = sentenceAnn.get(TreeAnnotation.class);
if (tree.children().length != 1) {
throw new RuntimeException("Expected single root node, found " + tree);
}
tree = tree.firstChild();
tree.indexSpans(0);
TopTreebankNode root = new TopTreebankNode(jCas);
root.setTreebankParse(tree.toString());
// TODO: root.setTerminals(v)
this.addTreebankNodeToIndexes(root, jCas, tree, tokenAnns);
// get the dependencies
SemanticGraph dependencies =
sentenceAnn.get(CollapsedCCProcessedDependenciesAnnotation.class);
// convert Stanford nodes to UIMA annotations
List<Token> tokens = JCasUtil.selectCovered(jCas, Token.class, sentence);
Map<IndexedWord, DependencyNode> stanfordToUima = new HashMap<IndexedWord, DependencyNode>();
for (IndexedWord stanfordNode : dependencies.vertexSet()) {
int indexBegin = stanfordNode.get(BeginIndexAnnotation.class);
int indexEnd = stanfordNode.get(EndIndexAnnotation.class);
int tokenBegin = tokens.get(indexBegin).getBegin();
int tokenEnd = tokens.get(indexEnd - 1).getEnd();
DependencyNode node;
if (dependencies.getRoots().contains(stanfordNode)) {
node = new TopDependencyNode(jCas, tokenBegin, tokenEnd);
} else {
node = new DependencyNode(jCas, tokenBegin, tokenEnd);
}
stanfordToUima.put(stanfordNode, node);
}
// create relation annotations for each Stanford dependency
ArrayListMultimap<DependencyNode, DependencyRelation> headRelations =
ArrayListMultimap.create();
ArrayListMultimap<DependencyNode, DependencyRelation> childRelations =
ArrayListMultimap.create();
for (SemanticGraphEdge stanfordEdge : dependencies.edgeIterable()) {
DependencyRelation relation = new DependencyRelation(jCas);
DependencyNode head = stanfordToUima.get(stanfordEdge.getGovernor());
DependencyNode child = stanfordToUima.get(stanfordEdge.getDependent());
String relationType = stanfordEdge.getRelation().toString();
if (head == null || child == null || relationType == null) {
throw new RuntimeException(
String.format(
"null elements not allowed in relation:\nrelation=%s\nchild=%s\nhead=%s\n",
relation, child, head));
}
relation.setHead(head);
relation.setChild(child);
relation.setRelation(relationType);
relation.addToIndexes();
headRelations.put(child, relation);
childRelations.put(head, relation);
}
// set the relations for each node annotation
for (DependencyNode node : stanfordToUima.values()) {
List<DependencyRelation> heads = headRelations.get(node);
node.setHeadRelations(new FSArray(jCas, heads == null ? 0 : heads.size()));
if (heads != null) {
FSCollectionFactory.fillArrayFS(node.getHeadRelations(), heads);
}
List<DependencyRelation> children = childRelations.get(node);
node.setChildRelations(new FSArray(jCas, children == null ? 0 : children.size()));
if (children != null) {
FSCollectionFactory.fillArrayFS(node.getChildRelations(), children);
}
node.addToIndexes();
}
}
// map from spans to named entity mentions
Map<Span, NamedEntityMention> spanMentionMap = new HashMap<Span, NamedEntityMention>();
for (NamedEntityMention mention : JCasUtil.select(jCas, NamedEntityMention.class)) {
spanMentionMap.put(new Span(mention.getBegin(), mention.getEnd()), mention);
}
// add mentions for all entities identified by the coreference system
List<NamedEntity> entities = new ArrayList<NamedEntity>();
List<List<Token>> sentenceTokens = new ArrayList<List<Token>>();
for (Sentence sentence : JCasUtil.select(jCas, Sentence.class)) {
sentenceTokens.add(JCasUtil.selectCovered(jCas, Token.class, sentence));
}
Map<Integer, CorefChain> corefChains = document.get(CorefChainAnnotation.class);
for (CorefChain chain : corefChains.values()) {
List<NamedEntityMention> mentions = new ArrayList<NamedEntityMention>();
for (CorefMention corefMention : chain.getMentionsInTextualOrder()) {
// figure out the character span of the token
List<Token> tokens = sentenceTokens.get(corefMention.sentNum - 1);
int begin = tokens.get(corefMention.startIndex - 1).getBegin();
int end = tokens.get(corefMention.endIndex - 2).getEnd();
// use an existing named entity mention when possible; otherwise create a new one
NamedEntityMention mention = spanMentionMap.get(new Span(begin, end));
if (mention == null) {
mention = new NamedEntityMention(jCas, begin, end);
mention.addToIndexes();
}
mentions.add(mention);
}
// create an entity for the mentions
Collections.sort(
mentions,
new Comparator<NamedEntityMention>() {
@Override
public int compare(NamedEntityMention m1, NamedEntityMention m2) {
return m1.getBegin() - m2.getBegin();
}
});
// create mentions and add them to entity
NamedEntity entity = new NamedEntity(jCas);
entity.setMentions(new FSArray(jCas, mentions.size()));
int index = 0;
for (NamedEntityMention mention : mentions) {
mention.setMentionedEntity(entity);
entity.setMentions(index, mention);
index += 1;
}
entities.add(entity);
}
// add singleton entities for any named entities not picked up by coreference system
for (NamedEntityMention mention : JCasUtil.select(jCas, NamedEntityMention.class)) {
if (mention.getMentionedEntity() == null) {
NamedEntity entity = new NamedEntity(jCas);
entity.setMentions(new FSArray(jCas, 1));
entity.setMentions(0, mention);
mention.setMentionedEntity(entity);
entity.getMentions();
entities.add(entity);
}
}
// sort entities by document order
Collections.sort(
entities,
new Comparator<NamedEntity>() {
@Override
public int compare(NamedEntity o1, NamedEntity o2) {
return getFirstBegin(o1) - getFirstBegin(o2);
}
private int getFirstBegin(NamedEntity entity) {
int min = Integer.MAX_VALUE;
for (NamedEntityMention mention :
JCasUtil.select(entity.getMentions(), NamedEntityMention.class)) {
if (mention.getBegin() < min) {
min = mention.getBegin();
}
}
return min;
}
});
// add entities to document
for (NamedEntity entity : entities) {
entity.addToIndexes();
}
}
/**
* The core implementation of the search.
*
* @param root The root word to search from. Traditionally, this is the root of the sentence.
* @param candidateFragments The callback for the resulting sentence fragments. This is a
* predicate of a triple of values. The return value of the predicate determines whether we
* should continue searching. The triple is a triple of
* <ol>
* <li>The log probability of the sentence fragment, according to the featurizer and the
* weights
* <li>The features along the path to this fragment. The last element of this is the
* features from the most recent step.
* <li>The sentence fragment. Because it is relatively expensive to compute the resulting
* tree, this is returned as a lazy {@link Supplier}.
* </ol>
*
* @param classifier The classifier for whether an arc should be on the path to a clause split, a
* clause split itself, or neither.
* @param featurizer The featurizer to use. Make sure this matches the weights!
* @param actionSpace The action space we are allowed to take. Each action defines a means of
* splitting a clause on a dependency boundary.
*/
protected void search(
// The root to search from
IndexedWord root,
// The output specs
final Predicate<Triple<Double, List<Counter<String>>, Supplier<SentenceFragment>>>
candidateFragments,
// The learning specs
final Classifier<ClauseSplitter.ClauseClassifierLabel, String> classifier,
Map<String, ? extends List<String>> hardCodedSplits,
final Function<Triple<State, Action, State>, Counter<String>> featurizer,
final Collection<Action> actionSpace,
final int maxTicks) {
// (the fringe)
PriorityQueue<Pair<State, List<Counter<String>>>> fringe = new FixedPrioritiesPriorityQueue<>();
// (avoid duplicate work)
Set<IndexedWord> seenWords = new HashSet<>();
State firstState =
new State(null, null, -9000, null, x -> {}, true); // First state is implicitly "done"
fringe.add(Pair.makePair(firstState, new ArrayList<>(0)), -0.0);
int ticks = 0;
while (!fringe.isEmpty()) {
if (++ticks > maxTicks) {
// System.err.println("WARNING! Timed out on search with " + ticks + " ticks");
return;
}
// Useful variables
double logProbSoFar = fringe.getPriority();
assert logProbSoFar <= 0.0;
Pair<State, List<Counter<String>>> lastStatePair = fringe.removeFirst();
State lastState = lastStatePair.first;
List<Counter<String>> featuresSoFar = lastStatePair.second;
IndexedWord rootWord = lastState.edge == null ? root : lastState.edge.getDependent();
// Register thunk
if (lastState.isDone) {
if (!candidateFragments.test(
Triple.makeTriple(
logProbSoFar,
featuresSoFar,
() -> {
SemanticGraph copy = new SemanticGraph(tree);
lastState
.thunk
.andThen(
x -> {
// Add the extra edges back in, if they don't break the tree-ness of the
// extraction
for (IndexedWord newTreeRoot : x.getRoots()) {
if (newTreeRoot != null) { // what a strange thing to have happen...
for (SemanticGraphEdge extraEdge :
extraEdgesByGovernor.get(newTreeRoot)) {
assert Util.isTree(x);
//noinspection unchecked
addSubtree(
x,
newTreeRoot,
extraEdge.getRelation().toString(),
tree,
extraEdge.getDependent(),
tree.getIncomingEdgesSorted(newTreeRoot));
assert Util.isTree(x);
}
}
}
})
.accept(copy);
return new SentenceFragment(copy, assumedTruth, false);
}))) {
break;
}
}
// Find relevant auxilliary terms
SemanticGraphEdge subjOrNull = null;
SemanticGraphEdge objOrNull = null;
for (SemanticGraphEdge auxEdge : tree.outgoingEdgeIterable(rootWord)) {
String relString = auxEdge.getRelation().toString();
if (relString.contains("obj")) {
objOrNull = auxEdge;
} else if (relString.contains("subj")) {
subjOrNull = auxEdge;
}
}
// Iterate over children
// For each outgoing edge...
for (SemanticGraphEdge outgoingEdge : tree.outgoingEdgeIterable(rootWord)) {
// Prohibit indirect speech verbs from splitting off clauses
// (e.g., 'said', 'think')
// This fires if the governor is an indirect speech verb, and the outgoing edge is a ccomp
if (outgoingEdge.getRelation().toString().equals("ccomp")
&& ((outgoingEdge.getGovernor().lemma() != null
&& INDIRECT_SPEECH_LEMMAS.contains(outgoingEdge.getGovernor().lemma()))
|| INDIRECT_SPEECH_LEMMAS.contains(outgoingEdge.getGovernor().word()))) {
continue;
}
// Get some variables
String outgoingEdgeRelation = outgoingEdge.getRelation().toString();
List<String> forcedArcOrder = hardCodedSplits.get(outgoingEdgeRelation);
if (forcedArcOrder == null && outgoingEdgeRelation.contains(":")) {
forcedArcOrder =
hardCodedSplits.get(
outgoingEdgeRelation.substring(0, outgoingEdgeRelation.indexOf(":")) + ":*");
}
boolean doneForcedArc = false;
// For each action...
for (Action action :
(forcedArcOrder == null ? actionSpace : orderActions(actionSpace, forcedArcOrder))) {
// Check the prerequisite
if (!action.prerequisitesMet(tree, outgoingEdge)) {
continue;
}
if (forcedArcOrder != null && doneForcedArc) {
break;
}
// 1. Compute the child state
Optional<State> candidate =
action.applyTo(tree, lastState, outgoingEdge, subjOrNull, objOrNull);
if (candidate.isPresent()) {
double logProbability;
ClauseClassifierLabel bestLabel;
Counter<String> features =
featurizer.apply(Triple.makeTriple(lastState, action, candidate.get()));
if (forcedArcOrder != null && !doneForcedArc) {
logProbability = 0.0;
bestLabel = ClauseClassifierLabel.CLAUSE_SPLIT;
doneForcedArc = true;
} else if (features.containsKey("__undocumented_junit_no_classifier")) {
logProbability = Double.NEGATIVE_INFINITY;
bestLabel = ClauseClassifierLabel.CLAUSE_INTERM;
} else {
Counter<ClauseClassifierLabel> scores = classifier.scoresOf(new RVFDatum<>(features));
if (scores.size() > 0) {
Counters.logNormalizeInPlace(scores);
}
String rel = outgoingEdge.getRelation().toString();
if ("nsubj".equals(rel) || "dobj".equals(rel)) {
scores.remove(
ClauseClassifierLabel.NOT_A_CLAUSE); // Always at least yield on nsubj and dobj
}
logProbability = Counters.max(scores, Double.NEGATIVE_INFINITY);
bestLabel = Counters.argmax(scores, (x, y) -> 0, ClauseClassifierLabel.CLAUSE_SPLIT);
}
if (bestLabel != ClauseClassifierLabel.NOT_A_CLAUSE) {
Pair<State, List<Counter<String>>> childState =
Pair.makePair(
candidate.get().withIsDone(bestLabel),
new ArrayList<Counter<String>>(featuresSoFar) {
{
add(features);
}
});
// 2. Register the child state
if (!seenWords.contains(childState.first.edge.getDependent())) {
// System.err.println(" pushing " + action.signature() + " with " +
// argmax.first.edge);
fringe.add(childState, logProbability);
}
}
}
}
}
seenWords.add(rootWord);
}
// System.err.println("Search finished in " + ticks + " ticks and " + classifierEvals + "
// classifier evaluations.");
}
/**
* A helper to add an entire subtree to a given dependency tree.
*
* @param toModify The tree to add the subtree to.
* @param root The root of the tree where we should be adding the subtree.
* @param rel The relation to add the subtree with.
* @param originalTree The orignal tree (i.e., {@link ClauseSplitterSearchProblem#tree}).
* @param subject The root of the clause to add.
* @param ignoredEdges The edges to ignore adding when adding this subtree.
*/
private static void addSubtree(
SemanticGraph toModify,
IndexedWord root,
String rel,
SemanticGraph originalTree,
IndexedWord subject,
Collection<SemanticGraphEdge> ignoredEdges) {
if (toModify.containsVertex(subject)) {
return; // This subtree already exists.
}
Queue<IndexedWord> fringe = new LinkedList<>();
Collection<IndexedWord> wordsToAdd = new ArrayList<>();
Collection<SemanticGraphEdge> edgesToAdd = new ArrayList<>();
// Search for subtree to add
for (SemanticGraphEdge edge : originalTree.outgoingEdgeIterable(subject)) {
if (!ignoredEdges.contains(edge)) {
if (toModify.containsVertex(edge.getDependent())) {
// Case: we're adding a subtree that's not disjoint from toModify. This is bad news.
return;
}
edgesToAdd.add(edge);
fringe.add(edge.getDependent());
}
}
while (!fringe.isEmpty()) {
IndexedWord node = fringe.poll();
wordsToAdd.add(node);
for (SemanticGraphEdge edge : originalTree.outgoingEdgeIterable(node)) {
if (!ignoredEdges.contains(edge)) {
if (toModify.containsVertex(edge.getDependent())) {
// Case: we're adding a subtree that's not disjoint from toModify. This is bad news.
return;
}
edgesToAdd.add(edge);
fringe.add(edge.getDependent());
}
}
}
// Add subtree
// (add subject)
toModify.addVertex(subject);
toModify.addEdge(
root,
subject,
GrammaticalRelation.valueOf(Language.English, rel),
Double.NEGATIVE_INFINITY,
false);
// (add nodes)
wordsToAdd.forEach(toModify::addVertex);
// (add edges)
for (SemanticGraphEdge edge : edgesToAdd) {
assert !toModify.incomingEdgeIterator(edge.getDependent()).hasNext();
toModify.addEdge(
edge.getGovernor(),
edge.getDependent(),
edge.getRelation(),
edge.getWeight(),
edge.isExtra());
}
}
/**
* Fix some bizarre peculiarities with certain trees. So far, these include:
*
* <ul>
* <li>Sometimes there's a node from a word to itself. This seems wrong.
* </ul>
*
* @param tree The tree to clean (in place!).
* @return A list of extra edges, which are valid but were removed.
*/
public static List<SemanticGraphEdge> cleanTree(SemanticGraph tree) {
// assert !isCyclic(tree);
// Clean nodes
List<IndexedWord> toDelete = new ArrayList<>();
for (IndexedWord vertex : tree.vertexSet()) {
// Clean punctuation
if (vertex.tag() == null) {
continue;
}
char tag = vertex.backingLabel().tag().charAt(0);
if (tag == '.' || tag == ',' || tag == '(' || tag == ')' || tag == ':') {
if (!tree.outgoingEdgeIterator(vertex)
.hasNext()) { // This should really never happen, but it does.
toDelete.add(vertex);
}
}
}
toDelete.forEach(tree::removeVertex);
// Clean edges
Iterator<SemanticGraphEdge> iter = tree.edgeIterable().iterator();
while (iter.hasNext()) {
SemanticGraphEdge edge = iter.next();
if (edge.getDependent().index() == edge.getGovernor().index()) {
// Clean self-edges
iter.remove();
} else if (edge.getRelation().toString().equals("punct")) {
// Clean punctuation (again)
if (!tree.outgoingEdgeIterator(edge.getDependent())
.hasNext()) { // This should really never happen, but it does.
iter.remove();
}
}
}
// Remove extra edges
List<SemanticGraphEdge> extraEdges = new ArrayList<>();
for (SemanticGraphEdge edge : tree.edgeIterable()) {
if (edge.isExtra()) {
if (tree.incomingEdgeList(edge.getDependent()).size() > 1) {
extraEdges.add(edge);
}
}
}
extraEdges.forEach(tree::removeEdge);
// Add apposition edges (simple coref)
for (SemanticGraphEdge extraEdge :
new ArrayList<>(extraEdges)) { // note[gabor] prevent concurrent modification exception
for (SemanticGraphEdge candidateAppos : tree.incomingEdgeIterable(extraEdge.getDependent())) {
if (candidateAppos.getRelation().toString().equals("appos")) {
extraEdges.add(
new SemanticGraphEdge(
extraEdge.getGovernor(),
candidateAppos.getGovernor(),
extraEdge.getRelation(),
extraEdge.getWeight(),
extraEdge.isExtra()));
}
}
for (SemanticGraphEdge candidateAppos : tree.outgoingEdgeIterable(extraEdge.getDependent())) {
if (candidateAppos.getRelation().toString().equals("appos")) {
extraEdges.add(
new SemanticGraphEdge(
extraEdge.getGovernor(),
candidateAppos.getDependent(),
extraEdge.getRelation(),
extraEdge.getWeight(),
extraEdge.isExtra()));
}
}
}
// Brute force ensure tree
// Remove incoming edges from roots
List<SemanticGraphEdge> rootIncomingEdges = new ArrayList<>();
for (IndexedWord root : tree.getRoots()) {
for (SemanticGraphEdge incomingEdge : tree.incomingEdgeIterable(root)) {
rootIncomingEdges.add(incomingEdge);
}
}
rootIncomingEdges.forEach(tree::removeEdge);
// Loop until it becomes a tree.
boolean changed = true;
while (changed) { // I just want trees to be trees; is that so much to ask!?
changed = false;
List<IndexedWord> danglingNodes = new ArrayList<>();
List<SemanticGraphEdge> invalidEdges = new ArrayList<>();
for (IndexedWord vertex : tree.vertexSet()) {
// Collect statistics
Iterator<SemanticGraphEdge> incomingIter = tree.incomingEdgeIterator(vertex);
boolean hasIncoming = incomingIter.hasNext();
boolean hasMultipleIncoming = false;
if (hasIncoming) {
incomingIter.next();
hasMultipleIncoming = incomingIter.hasNext();
}
// Register actions
if (!hasIncoming && !tree.getRoots().contains(vertex)) {
danglingNodes.add(vertex);
} else {
if (hasMultipleIncoming) {
for (SemanticGraphEdge edge : new IterableIterator<>(incomingIter)) {
invalidEdges.add(edge);
}
}
}
}
// Perform actions
for (IndexedWord vertex : danglingNodes) {
tree.removeVertex(vertex);
changed = true;
}
for (SemanticGraphEdge edge : invalidEdges) {
tree.removeEdge(edge);
changed = true;
}
}
// Return
assert isTree(tree);
return extraEdges;
}