1 files changed, 60 insertions, 0 deletions

diff --git a/src/main/scala/rsacomb/RDFTriple.scala b/src/main/scala/rsacomb/RDFTriple.scala
new file mode 100644
index 0000000..11ad6d4
--- /dev/null
+++ b/src/main/scala/rsacomb/RDFTriple.scala
@@ -0,0 +1,60 @@
+package rsacomb
+
+import tech.oxfordsemantic.jrdfox.logic.{Atom, IRI, TupleTableName}
+
+trait RDFTriple {
+
+  implicit class RDFTriple(atom: Atom) {
+
+    /* Is this the best way to determine if an atom is an RDF triple?
+     * Note that we can't use `getNumberOfArguments()` because is not
+     * "consistent":
+     * - for an atom created with `rdf(<term1>, <term2>, <term3>)`,
+     * `getNumberOfArguments` returns 3
+     * - for an atom created with `Atom.create(<tupletablename>, <term1>,
+     * <term2>, <term3>)`, `getNumberOfArguments()` returns 3
+     *
+     * This is probably because `Atom.rdf(...) is implemented as:
+     * ```scala
+     *  def rdf(term1: Term, term2: Term, term3: Term): Atom =
+     *    Atom.create(TupleTableName.create("internal:triple"), term1, term2, term3)
+     * ```
+     */
+    def isRdfTriple: Boolean =
+      atom.getTupleTableName.getIRI.equals("internal:triple")
+
+    def isClassAssertion: Boolean =
+      atom.isRdfTriple && atom.getArgument(1).equals(IRI.RDF_TYPE)
+
+    def isRoleAssertion: Boolean =
+      atom.isRdfTriple && !atom.getArgument(1).equals(IRI.RDF_TYPE)
+
+    def suffix(sx: String): Atom =
+      if (this.isClassAssertion) {
+        val newclass = atom.getArgument(2) match {
+          case iri: IRI => IRI.create(iri.getIRI.appendedAll(sx))
+          case other    => other
+        }
+        Atom.rdf(
+          atom getArgument 0,
+          atom getArgument 1,
+          newclass
+        )
+      } else if (this.isRoleAssertion) {
+        val newrole = atom.getArgument(1) match {
+          case iri: IRI => IRI.create(iri.getIRI.appendedAll(sx))
+          case other    => other
+        }
+        Atom.rdf(
+          atom getArgument 0,
+          newrole,
+          atom getArgument 2
+        )
+      } else {
+        val newname =
+          TupleTableName.create(atom.getTupleTableName.getIRI.appendedAll(sx))
+        Atom.create(newname, atom.getArguments())
+      }
+  }
+
+}