Github user jessehatfield commented on a diff in the pull request:
https://github.com/apache/incubator-rya/pull/206#discussion_r134081316
--- Diff:
sail/src/main/java/org/apache/rya/rdftriplestore/inference/InferenceEngine.java
---
@@ -416,22 +425,131 @@ private void
refreshHasValueRestrictions(Map<Resource, URI> restrictions) throws
}
}
- private static Vertex getVertex(Graph graph, Object id) {
- Iterator<Vertex> it = graph.vertices(id.toString());
+ private void refreshIntersectionOf() throws QueryEvaluationException {
+ final Map<Resource, List<Set<Resource>>> intersectionsProp = new
HashMap<>();
+
+ // First query for all the owl:intersectionOf's.
+ // If we have the following intersectionOf:
+ // :A owl:intersectionOf[:B, :C]
+ // It will be represented by triples following a pattern similar
to:
+ // <:A> owl:intersectionOf _:bnode1 .
+ // _:bnode1 rdf:first <:B> .
+ // _:bnode1 rdf:rest _:bnode2 .
+ // _:bnode2 rdf:first <:C> .
+ // _:bnode2 rdf:rest rdf:nil .
+ ryaDaoQueryWrapper.queryAll(null, OWL.INTERSECTIONOF, null, new
RyaDaoStatementIterHandler() {
+ @Override
+ public void handleStatementIter(final Statement st1) throws
Exception {
+ final Resource type = st1.getSubject();
+ // head will point to a type that is part of the
intersection.
+ URI head = (URI) st1.getObject();
+ if (!intersectionsProp.containsKey(type)) {
+ intersectionsProp.put(type, new
ArrayList<Set<Resource>>());
+ }
+ final Set<Resource> intersection = new HashSet<>();
+ // Go through and find all bnodes that are part of the
defined
+ // intersection.
+ while (!RDF.NIL.equals(head)) {
+ // rdf.first will point to a type item that is in the
+ // intersection.
+ ryaDaoQueryWrapper.queryFirst(head, RDF.FIRST, null,
new RyaDaoStatementIterHandler() {
+ @Override
+ public void handleStatementIter(final Statement
st2) throws Exception{
+ // The object found in the query represents a
type
+ // that should be included in the intersection.
+ final URI obj2 = (URI) st2.getObject();
+ intersection.add(obj2);
+ }
+ });
+ final List<URI> headHolder = new ArrayList<>(1);
+ // rdf.rest will point to the next bnode that's part
of the
+ // intersection.
+ ryaDaoQueryWrapper.queryFirst(head, RDF.REST, null,
new RyaDaoStatementIterHandler() {
+ @Override
+ public void handleStatementIter(final Statement
st3) throws Exception {
+ // This object is the next bnode head to look
for.
+ final URI obj3 = (URI) st3.getObject();
+ headHolder.add(obj3);
+ }
+ });
+ // As long as we get a new head there are more bnodes
that
+ // are part of the intersection. Keep going until we
reach
+ // rdf.nil.
+ if (!headHolder.isEmpty()) {
+ head = headHolder.get(0);
+ } else {
+ head = RDF.NIL;
+ }
+ }
+ // Add this intersection for this type. There may be more
+ // intersections for this type so each type has a list of
+ // intersection sets.
+ intersectionsProp.get(type).add(intersection);
+ }
+ });
+
+ for (final Map.Entry<Resource, List<Set<Resource>>> entry :
intersectionsProp.entrySet()) {
+ final Resource type = entry.getKey();
+ final List<Set<Resource>> intersectionList = entry.getValue();
+ final Set<Resource> otherTypes = new HashSet<>();
+ // Combine all of a type's intersections together.
+ for (final Set<Resource> intersection : intersectionList) {
+ otherTypes.addAll(intersection);
+ }
+ for (final Resource other : otherTypes) {
+ // :A intersectionOf[:B, :C] implies that
+ // :A subclassOf :B
+ // :A subclassOf :C
+ // So add each type that's part of the intersection to the
+ // subClassOf graph.
+ addSubClassOf(type, other);
+ for (final Set<Resource> intersection : intersectionList) {
+ if (!intersection.contains(other)) {
+ addIntersection(intersection, other);
--- End diff --
I'm not sure if that's the same. I can read "A = (B and C)" two ways --
either "A is the intersection of B and C":
<A> owl:intersectionOf (<B> <C>) .
<D> owl:intersectionOf (<B> <C>) .
<D> rdfs:subClassOf <E> .
or "A is equivalent to some anonymous class which is the intersection of B
and C:
<A> owl:equivalentClass _:bnode
_:bnode owl:intersectionOf (<B> <C>) .
_:bnode owl:equivalentClass <D> .
<D> rdfs:subClassOf <E> .
In the latter case, we have A subClassOf E just from subclass and
equivalent class transitivity, without touching the intersection.
In the former, I suppose you could infer that A and D are equivalent
classes by comparing their intersections. That would require comparing the
actual contents of all intersection lists to find any pairs that contain the
same set of classes. That might be something to do in the future, but I don't
think I'd try to do it at this point since we're not making that kind of check
with any of the other class expressions (unions, property restrictions, etc).
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