Add support for data property domain axioms

Also reintroduce data property axioms in LUBM

3 files changed, 55 insertions, 1 deletions

diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxAxiomConverter.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxAxiomConverter.scala
index 6f85893..93d8f8c 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxAxiomConverter.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxAxiomConverter.scala
@@ -109,6 +109,9 @@ class RDFoxAxiomConverter(
     List(Rule.create(range.res, range.ext ::: prop))
   }
 
+  override def visit(axiom: OWLDataPropertyDomainAxiom): List[Rule] =
+    axiom.asOWLSubClassOfAxiom.accept(this)
+
   override def visit(axiom: OWLInverseObjectPropertiesAxiom): List[Rule] =
     axiom.asSubObjectPropertyOfAxioms.asScala.toList.flatMap(_.accept(this))
 
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxClassExprConverter.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxClassExprConverter.scala
index c151c9a..9b7a004 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxClassExprConverter.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxClassExprConverter.scala
@@ -7,6 +7,7 @@ import org.semanticweb.owlapi.model.{
   OWLClassExpression,
   OWLClass,
   OWLObjectSomeValuesFrom,
+  OWLDataSomeValuesFrom,
   OWLObjectIntersectionOf,
   OWLObjectOneOf,
   OWLObjectMaxCardinality
@@ -133,6 +134,46 @@ class RDFoxClassExprConverter(
     )
   }
 
+  /** Converts a [[org.semanticweb.owlapi.model.OWLDataSomeValuesFrom OWLDataSomeValuesFrom]]
+    *
+    * @note we assume the expression is "simple", meaning that the
+    * property involved is a role name or the inverse of a role name.
+    * This assumption will be lifted when we will deal with the
+    * normalization of the input ontology.
+    *
+    * @todo the "filler" of this OWL expression is currently ignored. We
+    * need to find a way (if any) to handle
+    * [[org.semanticweb.owlapi.model.OWLDataRange OWLDataRange]]
+    * in RDFox.
+    */
+  override def visit(expr: OWLDataSomeValuesFrom): RDFoxRuleShards = {
+    val y = RSAOntology.genFreshVariable()
+    val prop = expr.getProperty()
+    // Computes the result of rule skolemization. Depending on the used
+    // technique it might involve the introduction of additional atoms,
+    // and/or fresh constants and variables.
+    val (head, body, term1) = skolem match {
+      case SkolemStrategy.None        => (List(), List(), y)
+      case SkolemStrategy.Constant(c) => (List(), List(), c)
+      case SkolemStrategy.ConstantRSA(c) => {
+        if (unsafe.contains(prop))
+          (List(RSA.PE(term, c), RSA.U(c)), List(), c)
+        else
+          (List(), List(), c)
+      }
+      case SkolemStrategy.Standard(f) => {
+        (
+          List(),
+          List(BindAtom.create(FunctionCall.create("SKOLEM", f, term), y)),
+          y
+        )
+      }
+    }
+    val propertyVisitor = new RDFoxPropertyExprConverter(term, term1, suffix)
+    val propertyResult = expr.getProperty.accept(propertyVisitor)
+    RDFoxRuleShards(head ::: propertyResult, body)
+  }
+
   // OWLObjectMaxCardinality
   override def visit(expr: OWLObjectMaxCardinality): RDFoxRuleShards = {
     // TODO: again, no hardcoded variables
diff --git a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxPropertyExprConverter.scala b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxPropertyExprConverter.scala
index 94c7887..d5a7384 100644
--- a/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxPropertyExprConverter.scala
+++ b/src/main/scala/uk/ac/ox/cs/rsacomb/converter/RDFoxPropertyExprConverter.scala
@@ -1,6 +1,10 @@
 package uk.ac.ox.cs.rsacomb.converter
 
-import org.semanticweb.owlapi.model.{OWLPropertyExpression, OWLObjectProperty}
+import org.semanticweb.owlapi.model.{
+  OWLPropertyExpression,
+  OWLObjectProperty,
+  OWLDataProperty
+}
 import org.semanticweb.owlapi.model.OWLPropertyExpressionVisitorEx
 
 import tech.oxfordsemantic.jrdfox.logic.datalog.TupleTableAtom
@@ -25,6 +29,12 @@ class RDFoxPropertyExprConverter(
     List(TupleTableAtom.rdf(term1, pred, term2))
   }
 
+  override def visit(expr: OWLDataProperty): List[TupleTableAtom] = {
+    val base = expr.getIRI.getIRIString
+    val pred = IRI.create(base :: suffix)
+    List(TupleTableAtom.rdf(term1, pred, term2))
+  }
+
   override def visit(expr: OWLObjectInverseOf): List[TupleTableAtom] = {
     val visitor = new RDFoxPropertyExprConverter(term1, term2, suffix + Inverse)
     expr.getInverse.accept(visitor)