1 files changed, 27 insertions, 13 deletions

diff --git a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
index ae8c70e0..f64d4066 100644
--- a/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
+++ b/subprojects/language-ide/src/main/java/tools/refinery/language/ide/syntaxcoloring/ProblemSemanticHighlightingCalculator.java
@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2023 The Refinery Authors <https://refinery.tools/>
+ * SPDX-FileCopyrightText: 2021-2024 The Refinery Authors <https://refinery.tools/>
  *
  * SPDX-License-Identifier: EPL-2.0
  */
@@ -38,9 +38,12 @@ public class ProblemSemanticHighlightingCalculator extends DefaultSemanticHighli
         @Inject
         private ProblemDesugarer desugarer;
 
+        @Inject
+        private TypeHashProvider typeHashProvider;
+
         @Override
         protected boolean highlightElement(EObject object, IHighlightedPositionAcceptor acceptor,
-                        CancelIndicator cancelIndicator) {
+                                                                           CancelIndicator cancelIndicator) {
                 highlightName(object, acceptor);
                 highlightCrossReferences(object, acceptor, cancelIndicator);
                 return false;
@@ -57,7 +60,7 @@ public class ProblemSemanticHighlightingCalculator extends DefaultSemanticHighli
         }
 
         protected void highlightCrossReferences(EObject object, IHighlightedPositionAcceptor acceptor,
-                        CancelIndicator cancelIndicator) {
+                                                                                        CancelIndicator cancelIndicator) {
                 for (EReference reference : object.eClass().getEAllReferences()) {
                         if (reference.isContainment()) {
                                 continue;
@@ -98,7 +101,7 @@ public class ProblemSemanticHighlightingCalculator extends DefaultSemanticHighli
                 boolean isError = ProblemUtil.isError(eObject);
                 if (ProblemUtil.isBuiltIn(eObject)) {
                         var className = isError ? ERROR_CLASS : BUILTIN_CLASS;
-                        return new String[] { className };
+                        return new String[]{className};
                 }
                 return getUserDefinedElementHighlightClass(eObject, reference, isError);
         }
@@ -113,21 +116,32 @@ public class ProblemSemanticHighlightingCalculator extends DefaultSemanticHighli
                                 && desugarer.isContainmentReference(referenceDeclaration)) {
                         classesBuilder.add(CONTAINMENT_CLASS);
                 }
-                if (isError) {
+                if (isError && reference != null) {
+                        // References to error patterns should be highlighted as errors, but error pattern definitions shouldn't.
                         classesBuilder.add(ERROR_CLASS);
                 }
                 if (eObject instanceof Node node) {
-                        if (reference == ProblemPackage.Literals.VARIABLE_OR_NODE_EXPR__VARIABLE_OR_NODE) {
-                                classesBuilder.add(NODE_CLASS);
-                        }
-                        if (ProblemUtil.isIndividualNode(node)) {
-                                classesBuilder.add(INDIVIDUAL_NODE_CLASS);
-                        }
-                        if (ProblemUtil.isNewNode(node)) {
-                                classesBuilder.add(NEW_NODE_CLASS);
+                        highlightNode(node, reference, classesBuilder);
+                }
+                if (eObject instanceof Relation relation) {
+                        var typeHash = typeHashProvider.getTypeHash(relation);
+                        if (typeHash != null) {
+                                classesBuilder.add("typeHash-" + typeHash);
                         }
                 }
                 List<String> classes = classesBuilder.build();
                 return classes.toArray(new String[0]);
         }
+
+        private static void highlightNode(Node node, EReference reference, ImmutableList.Builder<String> classesBuilder) {
+                if (reference == ProblemPackage.Literals.VARIABLE_OR_NODE_EXPR__VARIABLE_OR_NODE) {
+                        classesBuilder.add(NODE_CLASS);
+                }
+                if (ProblemUtil.isIndividualNode(node)) {
+                        classesBuilder.add(INDIVIDUAL_NODE_CLASS);
+                }
+                if (ProblemUtil.isNewNode(node)) {
+                        classesBuilder.add(NEW_NODE_CLASS);
+                }
+        }
 }