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package edu.stanford.nlp.semgraph;
import edu.stanford.nlp.ling.CoreAnnotations;
import edu.stanford.nlp.ling.CoreLabel;
import edu.stanford.nlp.ling.IndexedWord;
import edu.stanford.nlp.trees.*;
import java.util.function.Predicate;
import edu.stanford.nlp.util.Filters;
import edu.stanford.nlp.util.Generics;
import java.util.*;
/**
* Refactoring of static makers of SemanticGraphs in order to simplify
* the SemanticGraph class.
*
* @author rafferty
*/
public class SemanticGraphFactory {
private SemanticGraphFactory() {} // just static factory methods
private static final boolean INCLUDE_PUNCTUATION_DEPENDENCIES = false;
public enum Mode {
COLLAPSED_TREE,
/** collapse: Whether to do "collapsing" of pairs of dependencies into
* single dependencies, e.g., for prepositions and conjunctions.
*/
COLLAPSED,
/** ccProcess: Whether to do processing of CC complements resulting from
* collapsing. This argument is ignored unless collapse is
* true.
*/
CCPROCESSED,
BASIC
}
/**
* Produces an Uncollapsed SemanticGraph with no extras.
*/
public static SemanticGraph generateUncollapsedDependencies(Tree tree) {
return makeFromTree(tree, Mode.BASIC, false, true);
}
/**
* Produces a Collapsed SemanticGraph with no extras.
*/
public static SemanticGraph generateCollapsedDependencies(Tree tree) {
return makeFromTree(tree, Mode.COLLAPSED, false, true);
}
/**
* Produces a CCProcessed SemanticGraph with no extras.
*/
public static SemanticGraph generateCCProcessedDependencies(Tree tree) {
return makeFromTree(tree, Mode.CCPROCESSED, false, true);
}
/**
* Produces an Uncollapsed SemanticGraph with no extras.
*/
public static SemanticGraph generateUncollapsedDependencies(GrammaticalStructure gs) {
return makeFromTree(gs, Mode.BASIC, false, true, null);
}
/**
* Produces a Collapsed SemanticGraph with no extras.
*/
public static SemanticGraph generateCollapsedDependencies(GrammaticalStructure gs) {
return makeFromTree(gs, Mode.COLLAPSED, false, true, null);
}
/**
* Produces a CCProcessed SemanticGraph with no extras.
*/
public static SemanticGraph generateCCProcessedDependencies(GrammaticalStructure gs) {
return makeFromTree(gs, Mode.CCPROCESSED, false, true, null);
}
/**
* Returns a new SemanticGraph constructed from a given {@link
* Tree} with given options.
*
* This factory method is intended to replace a profusion of highly similar
* factory methods, such as
* typedDependencies(),
* typedDependenciesCollapsed(),
* allTypedDependencies(),
* allTypedDependenciesCollapsed(), etc.
*
* For a fuller explanation of the meaning of the boolean arguments, see
* {@link GrammaticalStructure}.
*
* @param tree A tree representing a phrase structure parse
* @param includeExtras Whether to include extra dependencies, which may
* result in a non-tree
* @param threadSafe Whether to make sure processing is thread-safe
* @param filter A filter to exclude certain dependencies; ignored if null
* @return A SemanticGraph
*/
public static SemanticGraph makeFromTree(Tree tree,
Mode mode,
boolean includeExtras,
boolean threadSafe,
Predicate filter) {
Predicate wordFilt;
if (INCLUDE_PUNCTUATION_DEPENDENCIES) {
wordFilt = Filters.acceptFilter();
} else {
wordFilt = new PennTreebankLanguagePack().punctuationWordRejectFilter();
}
GrammaticalStructure gs = new EnglishGrammaticalStructure(tree,
wordFilt,
new SemanticHeadFinder(true),
threadSafe);
return makeFromTree(gs, mode, includeExtras,
threadSafe, filter);
}
// TODO: these booleans would be more readable as enums similar to Mode.
// Then the arguments would make more sense
public static SemanticGraph makeFromTree(GrammaticalStructure gs,
Mode mode,
boolean includeExtras,
boolean threadSafe,
Predicate filter) {
addProjectedCategoriesToGrammaticalStructure(gs);
Collection deps;
switch(mode) {
case COLLAPSED_TREE:
deps = gs.typedDependenciesCollapsedTree();
break;
case COLLAPSED:
deps = gs.typedDependenciesCollapsed(includeExtras);
break;
case CCPROCESSED:
deps = gs.typedDependenciesCCprocessed(includeExtras);
break;
case BASIC:
deps = gs.typedDependencies(includeExtras);
break;
default:
throw new IllegalArgumentException("Unknown mode " + mode);
}
if (filter != null) {
List depsFiltered = Generics.newArrayList();
for (TypedDependency td : deps) {
if (filter.test(td)) {
depsFiltered.add(td);
}
}
deps = depsFiltered;
}
// there used to be an if clause that filtered out the case of empty
// dependencies. However, I could not understand (or replicate) the error
// it alluded to, and it led to empty dependency graphs for very short fragments,
// which meant they were ignored by the RTE system. Changed. (pado)
// See also the SemanticGraph constructor.
//System.err.println(deps.toString());
return new SemanticGraph(deps);
}
public static SemanticGraph makeFromTree(GrammaticalStructure structure) {
return makeFromTree(structure, Mode.BASIC, false, false, null);
}
public static SemanticGraph makeFromTree(Tree tree,
Mode mode,
boolean includeExtras,
Predicate filter) {
return makeFromTree(tree, mode, includeExtras, false, filter);
}
public static SemanticGraph makeFromTree(Tree tree,
Mode mode,
boolean includeExtras,
boolean threadSafe) {
return makeFromTree(tree, mode, includeExtras, threadSafe, null);
}
/**
* Returns a new SemanticGraph constructed from the given tree. Dependencies are collapsed
* according to the parameter "collapse", and extra dependencies are not included
* @param tree tree from which to make new semantic graph
* @param collapse collapse dependencies iff this parameter is true
*/
public static SemanticGraph makeFromTree(Tree tree, boolean collapse) {
return makeFromTree(tree, (collapse) ? Mode.COLLAPSED : Mode.BASIC, false, false, null);
}
/**
* Returns a new SemanticGraph constructed from the given tree. Dependencies are collapsed,
* and extra dependencies are not included (convenience method for makeFromTree(Tree tree, boolean collapse))
*/
public static SemanticGraph makeFromTree(Tree tree) {
return makeFromTree(tree, Mode.COLLAPSED, false, false, null);
}
/**
* Returns a new SemanticGraph constructed from the given tree. Collapsing
* of dependencies is performed according to "collapse". The list includes extra
* dependencies which do not respect a tree structure of the
* dependencies.
*
* (Internally, this invokes (@link
* edu.stanford.nlp.trees.GrammaticalStructure#allTypedDependencies()
* GrammaticalStructure.allTypedDependencies()).)
*
* @param tree tree from which to make new semantic graph
* @param collapse collapse dependencies iff this parameter is true
*/
// todo: Should we now update this to do CC process by default?
public static SemanticGraph allTypedDependencies(Tree tree, boolean collapse) {
return makeFromTree(tree, (collapse) ? Mode.COLLAPSED : Mode.BASIC, true, null);
}
/**
* Modifies the given GrammaticalStructure by adding some annotations to the
* MapLabels of certain nodes.
*
* For each word (leaf node), we add an annotation which indicates the
* syntactic category of the maximal constituent headed by the word.
*/
static void addProjectedCategoriesToGrammaticalStructure(GrammaticalStructure gs) {
// Our strategy: (1) assume every node in GrammaticalStructure is already
// annotated with head word, (2) traverse nodes of GrammaticalStructure in
// reverse of pre-order (bottom up), and (3) at each, get head word and
// annotate it with category of this node.
List nodes = new ArrayList();
for (Tree node : gs.root()) { // pre-order traversal
nodes.add((TreeGraphNode) node);
}
Collections.reverse(nodes); // reverse
for (TreeGraphNode node : nodes) {
if (!"ROOT".equals(node.value())) { // main verb should get PROJ_CAT "S", not "ROOT"
CoreLabel label = node.label();
Tree hw = label.get(TreeCoreAnnotations.HeadWordAnnotation.class);
if (hw != null) {
TreeGraphNode hwn = (TreeGraphNode) hw;
CoreLabel hwLabel = hwn.label();
hwLabel.set(CoreAnnotations.ProjectedCategoryAnnotation.class, node.value());
}
}
}
}
/**
* Given a list of edges, attempts to create and return a rooted SemanticGraph.
*
* TODO: throw Exceptions, or flag warnings on conditions for concern (no root, etc)
*/
public static SemanticGraph makeFromEdges(Iterable edges) {
// Identify the root(s) of this graph
SemanticGraph sg = new SemanticGraph();
Collection vertices = getVerticesFromEdgeSet(edges);
for (IndexedWord vertex : vertices) {
sg.addVertex(vertex);
}
for (SemanticGraphEdge edge : edges) {
sg.addEdge(edge.getSource(),edge.getTarget(), edge.getRelation(), edge.getWeight(), edge.isExtra());
}
sg.resetRoots();
return sg;
}
/**
* Given an iterable set of edges, returns the set of vertices covered by these edges.
*
* Note: CDM changed the return of this from a List to a Set in 2011. This seemed more
* sensible. Hopefully it doesn't break anything....
*/
public static Set getVerticesFromEdgeSet(Iterable edges) {
Set retSet = Generics.newHashSet();
for (SemanticGraphEdge edge : edges) {
retSet.add(edge.getGovernor());
retSet.add(edge.getDependent());
}
return retSet;
}
/**
* Given a set of vertices, and the source graph they are drawn from, create a path composed
* of the minimum paths between the vertices. i.e. this is a simple brain-dead attempt at getting
* something approximating a minimum spanning graph.
*
* NOTE: the hope is the vertices will already be contiguous, but facilities are added just in case for
* adding additional nodes.
*/
public static SemanticGraph makeFromVertices(SemanticGraph sg, Collection nodes) {
List edgesToAdd = new ArrayList();
List nodesToAdd = new ArrayList(nodes);
for (IndexedWord nodeA :nodes) {
for (IndexedWord nodeB : nodes) {
if (nodeA != nodeB) {
List edges = sg.getShortestDirectedPathEdges(nodeA, nodeB);
if (edges != null) {
edgesToAdd.addAll(edges);
for (SemanticGraphEdge edge : edges) {
IndexedWord gov = edge.getGovernor();
IndexedWord dep = edge.getDependent();
if (gov != null && !nodesToAdd.contains(gov)) {
nodesToAdd.add(gov);
}
if (dep != null && !nodesToAdd.contains(dep)) {
nodesToAdd.add(dep);
}
}
}
}
}
}
SemanticGraph retSg = new SemanticGraph();
for (IndexedWord node : nodesToAdd) {
retSg.addVertex(node);
}
for (SemanticGraphEdge edge : edgesToAdd) {
retSg.addEdge(edge.getGovernor(), edge.getDependent(), edge.getRelation(), edge.getWeight(), edge.isExtra());
}
retSg.resetRoots();
return retSg;
}
/**
* This creates a new graph based off the given, but uses the existing nodes objects.
*/
public static SemanticGraph duplicateKeepNodes(SemanticGraph sg) {
SemanticGraph retSg = new SemanticGraph();
for (IndexedWord node : sg.vertexSet()) {
retSg.addVertex(node);
}
retSg.setRoots(sg.getRoots());
for (SemanticGraphEdge edge : sg.edgeIterable()) {
retSg.addEdge(edge.getGovernor(), edge.getDependent(), edge.getRelation(), edge.getWeight(), edge.isExtra());
}
return retSg;
}
/**
* Given a list of graphs, constructs a new graph combined from the
* collection of graphs. Original vertices are used, edges are
* copied. Graphs are ordered by the sentence index and index of
* the original vertices. Intent is to create a "mega graph"
* similar to the graphs used in the RTE problem.
*
* This method only works if the indexed words have different
* sentence ids, as otherwise the maps used will confuse several of
* the IndexedWords.
*/
public static SemanticGraph makeFromGraphs(Collection sgList) {
SemanticGraph sg = new SemanticGraph();
Collection newRoots = Generics.newHashSet();
for (SemanticGraph currSg : sgList) {
newRoots.addAll(currSg.getRoots());
for (IndexedWord currVertex : currSg.vertexSet())
sg.addVertex(currVertex);
for (SemanticGraphEdge currEdge : currSg.edgeIterable())
sg.addEdge(currEdge.getGovernor(), currEdge.getDependent(),
currEdge.getRelation(), currEdge.getWeight(), currEdge.isExtra());
}
sg.setRoots(newRoots);
return sg;
}
/**
* Like makeFromGraphs, but it makes a deep copy of the graphs and
* renumbers the index words.
*
* lengths must be a vector containing the number of
* tokens in each sentence. This is used to reindex the tokens.
*/
public static SemanticGraph deepCopyFromGraphs(List graphs,
List lengths) {
SemanticGraph newGraph = new SemanticGraph();
Map newWords = Generics.newHashMap();
List newRoots = new ArrayList();
int vertexOffset = 0;
for (int i = 0; i < graphs.size(); ++i) {
SemanticGraph graph = graphs.get(i);
for (IndexedWord vertex : graph.vertexSet()) {
IndexedWord newVertex = new IndexedWord(vertex);
newVertex.setIndex(vertex.index() + vertexOffset);
newGraph.addVertex(newVertex);
newWords.put(newVertex.index(), newVertex);
}
for (SemanticGraphEdge edge : graph.edgeIterable()) {
IndexedWord gov = newWords.get(edge.getGovernor().index() +
vertexOffset);
IndexedWord dep = newWords.get(edge.getDependent().index() +
vertexOffset);
if (gov == null || dep == null) {
throw new AssertionError("Counting problem (or broken edge)");
}
newGraph.addEdge(gov, dep, edge.getRelation(), edge.getWeight(), edge.isExtra());
}
for (IndexedWord root : graph.getRoots()) {
newRoots.add(newWords.get(root.index() + vertexOffset));
}
vertexOffset += lengths.get(i);
}
newGraph.setRoots(newRoots);
return newGraph;
}
}