1 files changed, 48 insertions, 0 deletions

diff --git a/subprojects/store/src/main/java/tools/refinery/store/model/internal/UnaryVersionedInterpretation.java b/subprojects/store/src/main/java/tools/refinery/store/model/internal/UnaryVersionedInterpretation.java
new file mode 100644
index 00000000..75946680
--- /dev/null
+++ b/subprojects/store/src/main/java/tools/refinery/store/model/internal/UnaryVersionedInterpretation.java
@@ -0,0 +1,48 @@
+/*
+ * SPDX-FileCopyrightText: 2023 The Refinery Authors <https://refinery.tools/>
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package tools.refinery.store.model.internal;
+
+import tools.refinery.store.map.Cursor;
+import tools.refinery.store.map.Cursors;
+import tools.refinery.store.map.VersionedMap;
+import tools.refinery.store.representation.Symbol;
+import tools.refinery.store.tuple.Tuple;
+
+import java.util.Objects;
+
+class UnaryVersionedInterpretation<T> extends VersionedInterpretation<T> {
+        public UnaryVersionedInterpretation(ModelImpl model, Symbol<T> symbol, VersionedMap<Tuple, T> map) {
+                super(model, symbol, map);
+        }
+
+        private void validateSlot(int slot) {
+                if (slot != 0) {
+                        throw new IllegalArgumentException("Invalid index: " + slot);
+                }
+        }
+
+        @Override
+        public Cursor<Tuple, T> getAdjacent(int slot, int node) {
+                validateSlot(slot);
+                var key = Tuple.of(node);
+                var value = get(key);
+                if (Objects.equals(value, getSymbol().defaultValue())) {
+                        return Cursors.empty();
+                }
+                return Cursors.singleton(key, value);
+        }
+
+        @Override
+        public int getAdjacentSize(int slot, int node) {
+                validateSlot(slot);
+                var key = Tuple.of(node);
+                var value = get(key);
+                if (Objects.equals(value, getSymbol().defaultValue())) {
+                        return 0;
+                }
+                return 1;
+        }
+}