GH-5153 early detection of object equality when comparing Values or getting the effective boolean value

Author: hmottestad

core/queryalgebra/evaluation/src/main/java/org/eclipse/rdf4j/query/algebra/evaluation/util/QueryEvaluationUtil.java

@@ -20,6 +20,7 @@
 import org.eclipse.rdf4j.model.Value;
 import org.eclipse.rdf4j.model.base.CoreDatatype;
 import org.eclipse.rdf4j.model.datatypes.XMLDatatypeUtil;
+import org.eclipse.rdf4j.model.impl.BooleanLiteral;
 import org.eclipse.rdf4j.model.util.Literals;
 import org.eclipse.rdf4j.query.algebra.Compare.CompareOp;
 import org.eclipse.rdf4j.query.algebra.evaluation.ValueExprEvaluationException;
@@ -62,6 +63,13 @@ public class QueryEvaluationUtil {
 	 * @throws ValueExprEvaluationException In case the application of the EBV algorithm results in a type error.
 	 */
 	public static boolean getEffectiveBooleanValue(Value value) throws ValueExprEvaluationException {
+
+		if (value == BooleanLiteral.TRUE) {
+			return true;
+		} else if (value == BooleanLiteral.FALSE) {
+			return false;
+		}
+
 		if (value.isLiteral()) {
 			Literal literal = (Literal) value;
 			String label = literal.getLabel();
@@ -107,6 +115,15 @@ public static boolean compare(Value leftVal, Value rightVal, CompareOp operator)
 
 	public static boolean compare(Value leftVal, Value rightVal, CompareOp operator, boolean strict)
 			throws ValueExprEvaluationException {
+		if (leftVal == rightVal) {
+			switch (operator) {
+			case EQ:
+				return true;
+			case NE:
+				return false;
+			}
+		}
+
 		if (leftVal != null && leftVal.isLiteral() && rightVal != null && rightVal.isLiteral()) {
 			// Both left and right argument is a Literal
 			return compareLiterals((Literal) leftVal, (Literal) rightVal, operator, strict);
@@ -162,6 +179,15 @@ public static boolean compareLiterals(Literal leftLit, Literal rightLit, Compare
 		// - CoreDatatype.XSD:string
 		// - RDF term (equal and unequal only)
 
+		if (leftLit == rightLit) {
+			switch (operator) {
+			case EQ:
+				return true;
+			case NE:
+				return false;
+			}
+		}
+
 		CoreDatatype.XSD leftCoreDatatype = leftLit.getCoreDatatype().asXSDDatatypeOrNull();
 		CoreDatatype.XSD rightCoreDatatype = rightLit.getCoreDatatype().asXSDDatatypeOrNull();
 
@@ -329,7 +355,7 @@ && isSupportedDatatype(rightCoreDatatype)) {
 	 * <a href="http://www.w3.org/TR/rdf-concepts/#section-blank-nodes">6.6 Blank Nodes of [CONCEPTS]</a>.
 	 * </ul>
 	 * </blockquote>
-	 *
+	 * <p>
 	 * (emphasis ours)
 	 * <p>
 	 * When applying the SPARQL specification in a minimally-conforming manner, RDFterm-equal is supposed to return a
@@ -349,7 +375,6 @@ && isSupportedDatatype(rightCoreDatatype)) {
 	 * @param rightCoreDatatype the right datatype to compare
 	 * @throws ValueExprEvaluationException if query evaluation is operating in strict mode, and the two supplied
 	 *                                      datatypes are both supported datatypes but not comparable.
-	 *
 	 * @see <a href="https://github.com/eclipse/rdf4j/issues/3947">Github issue #3947</a>
 	 */
 	private static void validateDatatypeCompatibility(boolean strict, CoreDatatype.XSD leftCoreDatatype,