1 files changed, 28 insertions, 4 deletions

diff --git a/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/internal/DecisionTree.java b/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/internal/DecisionTree.java
index c1afecf9..32112e61 100644
--- a/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/internal/DecisionTree.java
+++ b/subprojects/language-semantics/src/main/java/tools/refinery/language/semantics/model/internal/DecisionTree.java
@@ -7,10 +7,10 @@ package tools.refinery.language.semantics.model.internal;
 
 import org.eclipse.collections.api.factory.primitive.IntObjectMaps;
 import tools.refinery.store.map.Cursor;
-import tools.refinery.store.tuple.Tuple;
 import tools.refinery.store.representation.TruthValue;
+import tools.refinery.store.tuple.Tuple;
 
-public class DecisionTree {
+class DecisionTree implements MutableSeed<TruthValue> {
         private final int levels;
 
         private final DecisionTreeNode root;
@@ -29,30 +29,53 @@ public class DecisionTree {
                 this(levels, null);
         }
 
+        @Override
+        public int arity() {
+                return levels;
+        }
+
+        @Override
+        public Class<TruthValue> valueType() {
+                return TruthValue.class;
+        }
+
+        @Override
+        public TruthValue reducedValue() {
+                return root.getOtherwiseReducedValue().getTruthValue();
+        }
+
+        @Override
         public TruthValue get(Tuple tuple) {
                 return root.getValue(levels - 1, tuple).getTruthValue();
         }
 
+        @Override
         public void mergeValue(Tuple tuple, TruthValue truthValue) {
                 if (truthValue != null) {
                         root.mergeValue(levels - 1, tuple, truthValue);
                 }
         }
 
+        @Override
         public void setIfMissing(Tuple tuple, TruthValue truthValue) {
                 if (truthValue != null) {
                         root.setIfMissing(levels - 1, tuple, truthValue);
                 }
         }
 
+        @Override
         public void setAllMissing(TruthValue truthValue) {
                 if (truthValue != null) {
                         root.setAllMissing(truthValue);
                 }
         }
 
-        public void overwriteValues(DecisionTree values) {
-                root.overwriteValues(values.root);
+        @Override
+        public void overwriteValues(MutableSeed<TruthValue> values) {
+                if (!(values instanceof DecisionTree decisionTree)) {
+                        throw new IllegalArgumentException("Incompatible overwrite: " + values);
+                }
+                root.overwriteValues(decisionTree.root);
         }
 
         public TruthValue getReducedValue() {
@@ -60,6 +83,7 @@ public class DecisionTree {
                 return reducedValue == null ? null : reducedValue.getTruthValue();
         }
 
+        @Override
         public Cursor<Tuple, TruthValue> getCursor(TruthValue defaultValue, int nodeCount) {
                 return new DecisionTreeCursor(levels, defaultValue, nodeCount, root);
         }