1 files changed, 11 insertions, 38 deletions

diff --git a/subprojects/store-query/src/main/java/tools/refinery/store/query/equality/LiteralEqualityHelper.java b/subprojects/store-query/src/main/java/tools/refinery/store/query/equality/LiteralEqualityHelper.java
index 9315fb30..5abc76ce 100644
--- a/subprojects/store-query/src/main/java/tools/refinery/store/query/equality/LiteralEqualityHelper.java
+++ b/subprojects/store-query/src/main/java/tools/refinery/store/query/equality/LiteralEqualityHelper.java
@@ -6,49 +6,22 @@
 package tools.refinery.store.query.equality;
 
 import tools.refinery.store.query.dnf.Dnf;
-import tools.refinery.store.query.dnf.SymbolicParameter;
 import tools.refinery.store.query.term.Variable;
 
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
+import java.util.Objects;
 
-public class LiteralEqualityHelper {
-        private final DnfEqualityChecker dnfEqualityChecker;
-        private final Map<Variable, Variable> leftToRight;
-        private final Map<Variable, Variable> rightToLeft;
-
-        public LiteralEqualityHelper(DnfEqualityChecker dnfEqualityChecker, List<SymbolicParameter> leftParameters,
-                                                                 List<SymbolicParameter> rightParameters) {
-                this.dnfEqualityChecker = dnfEqualityChecker;
-                var arity = leftParameters.size();
-                if (arity != rightParameters.size()) {
-                        throw new IllegalArgumentException("Parameter lists have unequal length");
-                }
-                leftToRight = new HashMap<>(arity);
-                rightToLeft = new HashMap<>(arity);
-                for (int i = 0; i < arity; i++) {
-                        if (!variableEqual(leftParameters.get(i).getVariable(), rightParameters.get(i).getVariable())) {
-                                throw new IllegalArgumentException("Parameter lists cannot be unified: duplicate parameter " + i);
-                        }
+public interface LiteralEqualityHelper extends DnfEqualityChecker {
+        LiteralEqualityHelper DEFAULT = new LiteralEqualityHelper() {
+                @Override
+                public boolean variableEqual(Variable left, Variable right) {
+                        return Objects.equals(left, right);
                 }
-        }
-
-        public boolean dnfEqual(Dnf left, Dnf right) {
-                return dnfEqualityChecker.dnfEqual(left, right);
-        }
 
-        public boolean variableEqual(Variable left, Variable right) {
-                if (checkMapping(leftToRight, left, right) && checkMapping(rightToLeft, right, left)) {
-                        leftToRight.put(left, right);
-                        rightToLeft.put(right, left);
-                        return true;
+                @Override
+                public boolean dnfEqual(Dnf left, Dnf right) {
+                        return DnfEqualityChecker.DEFAULT.dnfEqual(left, right);
                 }
-                return false;
-        }
+        };
 
-        private static boolean checkMapping(Map<Variable, Variable> map, Variable key, Variable expectedValue) {
-                var currentValue = map.get(key);
-                return currentValue == null || currentValue.equals(expectedValue);
-        }
+        boolean variableEqual(Variable left, Variable right);
 }