1 files changed, 77 insertions, 0 deletions

diff --git a/subprojects/store-query/src/main/java/tools/refinery/store/query/view/RelationView.java b/subprojects/store-query/src/main/java/tools/refinery/store/query/view/RelationView.java
new file mode 100644
index 00000000..d7164b3b
--- /dev/null
+++ b/subprojects/store-query/src/main/java/tools/refinery/store/query/view/RelationView.java
@@ -0,0 +1,77 @@
+package tools.refinery.store.query.view;
+
+import tools.refinery.store.map.CursorAsIterator;
+import tools.refinery.store.model.Model;
+import tools.refinery.store.representation.Symbol;
+import tools.refinery.store.tuple.Tuple;
+
+import java.util.Objects;
+import java.util.UUID;
+
+/**
+ * Represents a view of a {@link Symbol} that can be queried.
+ *
+ * @param <T>
+ * @author Oszkar Semerath
+ */
+public abstract non-sealed class RelationView<T> implements AnyRelationView {
+        private final Symbol<T> symbol;
+
+        private final String viewName;
+
+        protected RelationView(Symbol<T> symbol, String viewName) {
+                this.symbol = symbol;
+                this.viewName = viewName;
+        }
+
+        protected RelationView(Symbol<T> representation) {
+                this(representation, UUID.randomUUID().toString());
+        }
+
+        @Override
+        public Symbol<T> getSymbol() {
+                return symbol;
+        }
+
+        @Override
+        public String getViewName() {
+                return viewName;
+        }
+
+        @Override
+        public String name() {
+                return symbol.name() + "#" + viewName;
+        }
+
+        public abstract boolean filter(Tuple key, T value);
+
+        public abstract Object[] forwardMap(Tuple key, T value);
+
+        @Override
+        public Iterable<Object[]> getAll(Model model) {
+                return (() -> new CursorAsIterator<>(model.getInterpretation(symbol).getAll(), this::forwardMap, this::filter));
+        }
+
+        @Override
+        public String toString() {
+                return name();
+        }
+
+        @Override
+        public String toReferenceString() {
+                return "@RelationView(\"%s\") %s".formatted(viewName, symbol.name());
+        }
+
+        @Override
+        public boolean equals(Object o) {
+                if (this == o) return true;
+                if (o == null || getClass() != o.getClass()) return false;
+                RelationView<?> that = (RelationView<?>) o;
+                return Objects.equals(symbol, that.symbol) && Objects.equals(viewName, that.viewName);
+        }
+
+        @Override
+        public int hashCode() {
+                return Objects.hash(symbol, viewName);
+        }
+}