wip

core/model-api/src/main/java/org/eclipse/rdf4j/model/base/AbstractLiteral.java

@@ -211,6 +211,7 @@ static class TypedLiteral extends AbstractLiteral {
 		private final String label;
 		private final CoreDatatype coreDatatype;
 		private final IRI datatype;
+		transient private XMLGregorianCalendar cachedCalendarValue;
 
 		TypedLiteral(String label) {
 			this.label = label;
@@ -264,6 +265,16 @@ public IRI getDatatype() {
 		public CoreDatatype getCoreDatatype() {
 			return coreDatatype;
 		}
+
+		@Override
+		public XMLGregorianCalendar calendarValue() {
+			XMLGregorianCalendar localCalendar = cachedCalendarValue;
+			if (localCalendar == null) {
+				localCalendar = super.calendarValue();
+				cachedCalendarValue = localCalendar;
+			}
+			return localCalendar;
+		}
 	}
 
 	static class TaggedLiteral extends AbstractLiteral {

core/model-api/src/main/java/org/eclipse/rdf4j/model/base/CoreDatatype.java

@@ -22,47 +22,37 @@ public interface CoreDatatype {
 	CoreDatatype NONE = DefaultDatatype.NONE;
 
 	static int compare(CoreDatatype left, CoreDatatype right) {
-		assert left != NONE && right != NONE;
 		if (left.getClass() == right.getClass()) {
 			return Integer.compare(left.ordinal(), right.ordinal());
 		}
 
-		if (left.isXSDDatatype() && right.isRDFDatatype()) {
-			int ret = 1;
-			assert left.getIri().toString().compareTo(right.getIri().toString()) == ret;
-			return ret;
-		}
-		if (left.isXSDDatatype() && right.isGEODatatype()) {
-			int ret = 1;
-			assert left.getIri().toString().compareTo(right.getIri().toString()) == ret;
-			return ret;
-		}
-
-		if (left.isRDFDatatype() && right.isXSDDatatype()) {
-			int ret = -1;
-			assert left.getIri().toString().compareTo(right.getIri().toString()) == ret;
-			return ret;
-		}
-		if (left.isRDFDatatype() && right.isGEODatatype()) {
-			int ret = 1;
-			assert left.getIri().toString().compareTo(right.getIri().toString()) == ret;
-			return ret;
-		}
-
-		if (left.isGEODatatype() && right.isXSDDatatype()) {
-			int ret = -1;
-			assert left.getIri().toString().compareTo(right.getIri().toString()) == ret;
-			return ret;
-		}
-		if (left.isGEODatatype() && right.isRDFDatatype()) {
-			int ret = -1;
-			assert left.getIri().toString().compareTo(right.getIri().toString()) == ret;
-			return ret;
-		}
-
-		assert false;
-		return left.getIri().toString().compareTo(right.getIri().toString());
-
+		int compare;
+
+		if (left.isXSDDatatype()) {
+			if (right.isRDFDatatype() || right.isGEODatatype()) {
+				compare = 1;
+			} else {
+				compare = 0;
+			}
+		} else if (left.isRDFDatatype()) {
+			if (right.isXSDDatatype()) {
+				compare = -1;
+			} else if (right.isGEODatatype()) {
+				compare = 1;
+			} else {
+				compare = 0;
+			}
+		} else if (left.isGEODatatype()) {
+			if (right.isXSDDatatype() || right.isRDFDatatype()) {
+				compare = -1;
+			} else {
+				compare = 0;
+			}
+		} else {
+			compare = 0;
+		}
+
+		return compare;
 	}
 
 	int ordinal();
@@ -89,9 +79,6 @@ default Optional<XSD> asXSDDatatype() {
 	}
 
 	default XSD asXSDDatatypeOrNull() {
-		if (this.getClass() == XSD.class) {
-			return ((XSD) this);
-		}
 		return null;
 	}
 
@@ -319,6 +306,11 @@ public String toString() {
 			return iri.toString();
 		}
 
+		@Override
+		public final XSD asXSDDatatypeOrNull() {
+			return this;
+		}
+
 	}
 
 	enum RDF implements CoreDatatype {