From 58b8d3c11a9deebb40e21c70d0b085d01cada745 Mon Sep 17 00:00:00 2001
From: Federico Igne <federico.igne@cs.ox.ac.uk>
Date: Wed, 15 Jul 2020 17:44:00 +0100
Subject: Add reworked code from previous repo

---
 .../scala/example/RDFoxClassExprConverter.scala    | 119 +++++++++++++++++++++
 1 file changed, 119 insertions(+)
 create mode 100644 src/main/scala/example/RDFoxClassExprConverter.scala

(limited to 'src/main/scala/example/RDFoxClassExprConverter.scala')

diff --git a/src/main/scala/example/RDFoxClassExprConverter.scala b/src/main/scala/example/RDFoxClassExprConverter.scala
new file mode 100644
index 0000000..3e60461
--- /dev/null
+++ b/src/main/scala/example/RDFoxClassExprConverter.scala
@@ -0,0 +1,119 @@
+package rsacomb
+
+import scala.collection.JavaConverters._
+import java.util.stream.{Stream,Collectors}
+
+import org.semanticweb.owlapi.model.{OWLClassExpression, OWLClass, OWLObjectSomeValuesFrom, OWLObjectIntersectionOf, OWLObjectOneOf, OWLObjectMaxCardinality}
+import org.semanticweb.owlapi.model.OWLClassExpressionVisitorEx
+import tech.oxfordsemantic.jrdfox.logic.{AtomicFormula, Bind,BuiltinFunctionCall}
+import tech.oxfordsemantic.jrdfox.logic.{Atom, Predicate, Term, Variable, Literal, Individual}
+
+import rsacomb.SkolemStrategy
+import rsacomb.RDFoxRuleShards
+
+object RDFoxClassExprConverter {
+
+  def apply(term : Term, skolem : SkolemStrategy) : RDFoxClassExprConverter =
+	new RDFoxClassExprConverter(term, skolem)
+
+  def apply(term : Term) : RDFoxClassExprConverter =
+	new RDFoxClassExprConverter(term, SkolemStrategy.None)
+
+  def merge(rules : List[RDFoxRuleShards]) : RDFoxRuleShards = {
+    rules.foldLeft(RDFoxRuleShards(List(),List())) {
+      (r1,r2) =>
+        RDFoxRuleShards(
+          r1.res ++ r2.res,
+          r1.ext ++ r2.ext
+        )
+    }
+  }
+
+} // object RDFoxClassExprConverter
+
+class RDFoxClassExprConverter(term : Term, skolem : SkolemStrategy)
+  extends OWLClassExpressionVisitorEx[RDFoxRuleShards]
+{
+
+  // OWLClass
+  override
+  def visit(expr : OWLClass) : RDFoxRuleShards = {
+    val name = expr.getIRI.getIRIString
+    val atom = List(Atom.create(Predicate.create(name), term))
+    RDFoxRuleShards(atom,List())
+  }
+
+  // OWLObjectIntersectionOf
+  override
+  def visit(expr : OWLObjectIntersectionOf) : RDFoxRuleShards = {
+    val visitor = new RDFoxClassExprConverter(term,skolem)
+    // TODO: maybe using `flatMap` instead of `merge` + `map` works as well
+	RDFoxClassExprConverter.merge (
+      expr.asConjunctSet.asScala.toList
+          .map((e : OWLClassExpression) => e.accept(visitor))
+    )
+  }
+
+  // OWLObjectOneOf
+  override
+  def visit(expr : OWLObjectOneOf) : RDFoxRuleShards = {
+    val visitor = RDFoxClassExprConverter(term,skolem)
+    // TODO: review nominal handling. Here we are taking "just" one
+    val ind = expr.individuals.collect(Collectors.toList()).asScala
+                  .filter(_.isOWLNamedIndividual)
+                  .head // restricts to proper "nominals"
+                  .asOWLNamedIndividual.getIRI.getIRIString
+    val atom = List(Atom.create(
+      Predicate.create("owl:sameAs"), term, Individual.create(ind)
+    ))
+    RDFoxRuleShards(atom,List())
+  }
+
+  // OWLObjectSomeValuesFrom
+  override
+  def visit(expr : OWLObjectSomeValuesFrom) : RDFoxRuleShards = {
+    // TODO: variables needs to be handled at visitor level. Hardcoding
+    // the name of the varibles might lead to errors for complex cases.
+    val y = Variable.create("y")
+	val (fun,term1) = skolem match {
+      case SkolemStrategy.None => (List(),y)
+      case SkolemStrategy.Constant(c) => (List(), Individual.create(c))
+      case SkolemStrategy.Standard(f) => 
+        // At the time of writing the RDFox library does not have a
+        // particular class for the "SKOLEM" operator and it is instead
+        // a simple builtin function with a special name.
+        (List(Bind.create(BuiltinFunctionCall.create("SKOLEM",term),y)),y)
+	}
+    val classVisitor = new RDFoxClassExprConverter(term1,skolem)
+    val classResult = expr.getFiller.accept(classVisitor)
+    val propertyVisitor = new RDFoxPropertyExprConverter(term, term1, skolem)
+    val propertyResult = expr.getProperty.accept(propertyVisitor)
+    RDFoxRuleShards(
+      classResult.res ++ propertyResult,
+      fun ++ classResult.ext
+    )
+  }
+
+  // OWLObjectMaxCardinality
+  override
+  def visit(expr : OWLObjectMaxCardinality) : RDFoxRuleShards = {
+    // TODO: again, no hardcoded variables
+    val vars = List(Variable.create("y"),Variable.create("z"))
+    val classResult = RDFoxClassExprConverter.merge(
+      vars.map(new RDFoxClassExprConverter(_,skolem))
+          .map(expr.getFiller.accept(_))
+    )
+    val propertyResult = 
+      vars.map(new RDFoxPropertyExprConverter(term,_,skolem))
+          .map(expr.getProperty.accept(_))
+          .flatten
+    RDFoxRuleShards(
+      List(Atom.create(Predicate.create("owl:sameAs"),vars(0),vars(1))),
+      classResult.res ++ propertyResult
+    )
+  }
+	
+  def doDefault(expr : OWLClassExpression) : RDFoxRuleShards =
+    RDFoxRuleShards(List(),List())
+
+} // class RDFoxClassExprConverter
-- 
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