ST6RI-906 Fixed some problems with ExpressionEvaluator.

- Corrected instantiateInvocation to copy instantiatedType from the
original InvocationExpression, rather than the ownedTyping.

- Updated the evaluation of Features so that unbound input parameters
are considered to have a null value (rather than returning the Feature
itself).

Author: seidewitz

org.omg.sysml.execution/src/org/omg/sysml/execution/expressions/ExpressionEvaluator.java

@@ -1,6 +1,6 @@
 /*******************************************************************************
  * SysML 2 Pilot Implementation
- * Copyright (c) 2022-2025 Model Driven Solutions, Inc.
+ * Copyright (c) 2022-2026 Model Driven Solutions, Inc.
  *    
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -27,7 +27,6 @@
 import org.omg.sysml.lang.sysml.Element;
 import org.omg.sysml.lang.sysml.Expression;
 import org.omg.sysml.lang.sysml.Feature;
-import org.omg.sysml.lang.sysml.FeatureTyping;
 import org.omg.sysml.lang.sysml.FeatureValue;
 import org.omg.sysml.lang.sysml.Function;
 import org.omg.sysml.lang.sysml.InvocationExpression;
@@ -37,6 +36,7 @@
 import org.omg.sysml.util.ElementUtil;
 import org.omg.sysml.util.EvaluationUtil;
 import org.omg.sysml.util.FeatureUtil;
+import org.omg.sysml.util.NamespaceUtil;
 import org.omg.sysml.util.TypeUtil;
 
 public class ExpressionEvaluator extends ModelLevelExpressionEvaluator {
@@ -74,13 +74,9 @@ public EList<Element> evaluateInvocation(InvocationExpression expression, Elemen
 	protected InvocationExpression instantiateInvocation(InvocationExpression expression, Element target) {
 		InvocationExpression instantiation = SysMLFactory.eINSTANCE.createInvocationExpression();
 
-		// Copy typing from original expression.
-		for (FeatureTyping typing: expression.getOwnedTyping()) {
-			FeatureTyping newTyping = SysMLFactory.eINSTANCE.createFeatureTyping();
-			newTyping.setType(typing.getType());
-			newTyping.setTypedFeature(instantiation);
-			instantiation.getOwnedRelationship().add(newTyping);
-		}
+		// Copy instantiatedType from original expression.
+		Type instantiatedType = expression.getInstantiatedType();
+		NamespaceUtil.addMemberTo(instantiation, instantiatedType);
 
 		// Add implicit generalization.
 		ElementUtil.transform(instantiation);
@@ -119,4 +115,15 @@ protected InvocationExpression instantiateInvocation(InvocationExpression expres
 
 		return instantiation;
 	}
+	
+	@Override
+	public EList<Element> evaluateFeature(Feature feature, Type type) {
+		EList<Element> results = super.evaluateFeature(feature, type);
+		Element result = results == null || results.size() != 1? null: results.get(0);
+		
+		// Treat an unbound input parameter as if it was null.
+		return type != null && result instanceof Feature && !(result instanceof Expression) &&
+			   FeatureUtil.isInputParameter((Feature)results.get(0), type)? EvaluationUtil.nullList(): results;
+	}
+	
 }

org.omg.sysml.interactive.tests/src/org/omg/sysml/interactive/tests/ExpressionEvaluationTest.java

@@ -347,17 +347,19 @@ public void testIndexOperator() throws Exception {
 			+ "	   calc def Test {"
 			+ "        in x;"
 			+ "        in y;"
-			+ "        x"
+			+ "        (x, y)"
 			+ "     }"
 			+ "}";
 
 	@Test
 	public void testInvocationEvaluation() throws Exception {
 		SysMLInteractive instance = getSysMLInteractiveInstance();
 		process(instance, invocationTest);
-		assertElement("LiteralInteger 1", instance.eval("Test(1, 2)", "InvocationTest"));
-		assertElement("LiteralInteger 1", instance.eval("Test(x = 1, y = 2)", "InvocationTest"));
-		assertElement("LiteralInteger 1", instance.eval("Test(y = 2, x = 1)", "InvocationTest"));
+		assertList(new String[] {"LiteralInteger 1", "LiteralInteger 2"}, instance.eval("Test(1, 2)", "InvocationTest"));
+		assertList(new String[] {"LiteralInteger 1", "LiteralInteger 2"}, instance.eval("Test(x = 1, y = 2)", "InvocationTest"));
+		assertList(new String[] {"LiteralInteger 1", "LiteralInteger 2"}, instance.eval("Test(y = 2, x = 1)", "InvocationTest"));
+		assertList(new String[] {"LiteralInteger 1"}, instance.eval("Test(1)", "InvocationTest"));
+		assertList(new String[] {"LiteralInteger 2"}, instance.eval("Test(null, 2)", "InvocationTest"));
 	}
 
 	@Test
@@ -591,5 +593,5 @@ public void testTrigFunctionEvaluation() throws Exception {
 		assertElement("LiteralRational " + 90.0, instance.eval("TrigFunctions::deg(TrigFunctions::pi/2)", null));
 		assertElement("LiteralRational " + Math.PI/2, instance.eval("TrigFunctions::rad(90)", null));
 	}
-
+	
 }