Utils simplified

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/JenaTripleToNTripleString.scala

@@ -1,33 +1,21 @@
 package net.sansa_stack.inference.utils
 
 import org.apache.jena.graph.Triple
+import org.apache.jena.shared.PrefixMapping
+import org.apache.jena.sparql.util.FmtUtils
 
 
 /**
   * Convert a Jena Triple to an N-Triples string.
   *
+  * @note it turns out, that it might be more efficient to use the Jena stream based writer API per partition.
+  *
   * @author Lorenz Buehmann
   */
 class JenaTripleToNTripleString
     extends Function[Triple, String]
     with java.io.Serializable {
-  override def apply(t: Triple): String = {
-    val subStr =
-      if (t.getSubject.isBlank) {
-        s"_:${t.getSubject.getBlankNodeLabel}"
-      } else {
-        s"<${t.getSubject.getURI}>"
-      }
 
-    val objStr =
-      if (t.getObject.isLiteral) {
-        t.getObject
-      } else if (t.getObject.isBlank) {
-        s"_:${t.getObject}"
-      } else {
-        s"<${t.getObject}>"
-      }
-    s"$subStr <${t.getPredicate}> $objStr ."
-  }
+  override def apply(t: Triple): String = s"${FmtUtils.stringForTriple(t, null.asInstanceOf[PrefixMapping])} ."
 }
 

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/NTriplesStringToRDFTriple.scala

@@ -2,7 +2,6 @@ package net.sansa_stack.inference.utils
 
 import java.io.ByteArrayInputStream
 
-import org.apache.jena.graph.Triple
 import org.apache.jena.riot.{Lang, RDFDataMgr}
 
 import net.sansa_stack.inference.data.RDFTriple
@@ -13,7 +12,7 @@ import net.sansa_stack.inference.data.RDFTriple
   * @author Lorenz Buehmann
   */
 class NTriplesStringToRDFTriple
-    extends Function1[String, Option[RDFTriple]]
+    extends ((String) => Option[RDFTriple])
     with java.io.Serializable {
   override def apply(s: String): Option[RDFTriple] = {
     val t = RDFDataMgr.createIteratorTriples(new ByteArrayInputStream(s.getBytes), Lang.NTRIPLES, null).next()

sansa-inference-common/src/main/scala/net/sansa_stack/inference/utils/PredicateUtils.scala

@@ -0,0 +1,40 @@
+package net.sansa_stack.inference.utils
+
+/**
+  * Some utils for logical combinations of boolean functions.
+  */
+object PredicateUtils {
+
+  implicit class RichPredicate[A](f: A => Boolean) extends (A => Boolean) {
+    def apply(v: A): Boolean = f(v)
+
+    /**
+      * Logical 'and'.
+      *
+      * @param g
+      * @return
+      */
+    def &&(g: A => Boolean): A => Boolean = { x: A =>
+      f(x) && g(x)
+    }
+
+    /**
+      * Logical 'or'.
+      *
+      * @param g
+      * @return
+      */
+    def ||(g: A => Boolean): A => Boolean = { x: A =>
+      f(x) || g(x)
+    }
+
+    /**
+      * Logical 'not'
+      *
+      * @return
+      */
+    def unary_! : A => Boolean = { x: A =>
+      !f(x)
+    }
+  }
+}