1 files changed, 15 insertions, 20 deletions

diff --git a/subprojects/language/src/main/java/tools/refinery/language/scoping/ProblemScopeProvider.java b/subprojects/language/src/main/java/tools/refinery/language/scoping/ProblemScopeProvider.java
index a4437ba6..d94c9a13 100644
--- a/subprojects/language/src/main/java/tools/refinery/language/scoping/ProblemScopeProvider.java
+++ b/subprojects/language/src/main/java/tools/refinery/language/scoping/ProblemScopeProvider.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
  */
@@ -9,17 +9,15 @@
  */
 package tools.refinery.language.scoping;
 
-import com.google.inject.Inject;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.xtext.EcoreUtil2;
 import org.eclipse.xtext.scoping.IScope;
 import org.eclipse.xtext.scoping.Scopes;
 import tools.refinery.language.model.problem.*;
-import tools.refinery.language.utils.ProblemDesugarer;
 
-import java.util.ArrayList;
-import java.util.List;
+import java.util.Collection;
+import java.util.LinkedHashSet;
 
 /**
  * This class contains custom scoping description.
@@ -29,9 +27,6 @@ import java.util.List;
  * on how and when to use it.
  */
 public class ProblemScopeProvider extends AbstractProblemScopeProvider {
-        @Inject
-        private ProblemDesugarer desugarer;
-
         @Override
         public IScope getScope(EObject context, EReference reference) {
                 var scope = super.getScope(context, reference);
@@ -58,7 +53,7 @@ public class ProblemScopeProvider extends AbstractProblemScopeProvider {
         }
 
         protected IScope getVariableScope(EObject context, IScope delegateScope) {
-                List<Variable> variables = new ArrayList<>();
+                Collection<Variable> variables = new LinkedHashSet<>();
                 addSingletonVariableToScope(context, variables);
                 EObject currentContext = context;
                 while (currentContext != null && !(currentContext instanceof ParametricDefinition)) {
@@ -73,7 +68,7 @@ public class ProblemScopeProvider extends AbstractProblemScopeProvider {
                 return Scopes.scopeFor(variables, parentScope);
         }
 
-        protected void addSingletonVariableToScope(EObject context, List<Variable> variables) {
+        protected void addSingletonVariableToScope(EObject context, Collection<Variable> variables) {
                 if (context instanceof VariableOrNodeExpr expr) {
                         Variable singletonVariable = expr.getSingletonVariable();
                         if (singletonVariable != null) {
@@ -82,18 +77,21 @@ public class ProblemScopeProvider extends AbstractProblemScopeProvider {
                 }
         }
 
-        protected void addExistentiallyQualifiedVariableToScope(EObject currentContext, List<Variable> variables) {
-                if (currentContext instanceof ExistentialQuantifier quantifier) {
-                        variables.addAll(quantifier.getImplicitVariables());
-                } else if (currentContext instanceof Match match) {
-                        variables.addAll(match.getCondition().getImplicitVariables());
-                } else if (currentContext instanceof Consequent consequent) {
+        protected void addExistentiallyQualifiedVariableToScope(EObject currentContext, Collection<Variable> variables) {
+                switch (currentContext) {
+                case ExistentialQuantifier quantifier -> variables.addAll(quantifier.getImplicitVariables());
+                case Match match -> variables.addAll(match.getCondition().getImplicitVariables());
+                case Consequent consequent -> {
                         for (var literal : consequent.getActions()) {
                                 if (literal instanceof NewAction newAction && newAction.getVariable() != null) {
                                         variables.add(newAction.getVariable());
                                 }
                         }
                 }
+                default -> {
+                        // Nothing to add.
+                }
+                }
         }
 
         protected IScope getOppositeScope(EObject context) {
@@ -105,10 +103,7 @@ public class ProblemScopeProvider extends AbstractProblemScopeProvider {
                 if (!(relation instanceof ClassDeclaration classDeclaration)) {
                         return IScope.NULLSCOPE;
                 }
-                var referenceDeclarations = classDeclaration.getFeatureDeclarations()
-                                .stream()
-                                .filter(ReferenceDeclaration.class::isInstance)
-                                .toList();
+                var referenceDeclarations = classDeclaration.getFeatureDeclarations();
                 return Scopes.scopeFor(referenceDeclarations);
         }
 }