views of a for RelationRepresentations that can be queried.

1 files changed, 90 insertions, 0 deletions

diff --git a/model-data/src/main/java/org/eclipse/viatra/solver/data/query/RelationView.java b/model-data/src/main/java/org/eclipse/viatra/solver/data/query/RelationView.java
new file mode 100644
index 00000000..c52b9ff0
--- /dev/null
+++ b/model-data/src/main/java/org/eclipse/viatra/solver/data/query/RelationView.java
@@ -0,0 +1,90 @@
+package org.eclipse.viatra.solver.data.query;
+
+import java.util.function.BiFunction;
+import java.util.function.BiPredicate;
+
+import org.eclipse.viatra.solver.data.map.CursorAsIterator;
+import org.eclipse.viatra.solver.data.model.Model;
+import org.eclipse.viatra.solver.data.model.Tuple;
+import org.eclipse.viatra.solver.data.model.representation.RelationRepresentation;
+
+/**
+ * Represents a view of a {@link RelationRepresentation} that can be queried.
+ * @author Oszkar Semerath
+ *
+ * @param <D>
+ */
+public class RelationView<D>{
+        protected final Model model;
+        protected final RelationRepresentation<D> representation;
+        protected final BiPredicate<Tuple, D> filter;
+        protected final BiFunction<Tuple,D,Object[]> mapping;
+        
+        protected RelationView(Model model, RelationRepresentation<D> representation, BiPredicate<Tuple,D> filter, BiFunction<Tuple,D,Object[]> mapping) {
+                this.model = model;
+                this.representation = representation;
+                this.filter = filter;
+                this.mapping = mapping;
+                checkRepresentation(model, representation);
+        }
+        
+        protected RelationView(Model model, RelationRepresentation<D> representation, BiPredicate<Tuple,D> filter) {
+                this.model = model;
+                this.representation = representation;
+                this.filter = filter;
+                this.mapping = ((k,v)->toTuple1Array(k));
+                checkRepresentation(model, representation);
+        }
+        protected RelationView(Model model, RelationRepresentation<D> representation, BiFunction<Tuple,D,Object[]> mapping) {
+                this.model = model;
+                this.representation = representation;
+                this.filter = ((k,v)->true);
+                this.mapping = mapping;
+                checkRepresentation(model, representation);
+        }
+        protected RelationView(Model model, RelationRepresentation<D> representation) {
+                this.model = model;
+                this.representation = representation;
+                this.filter = ((k,v)->true);
+                this.mapping = (RelationView::toTuple1ArrayPlusValue);
+                checkRepresentation(model, representation);
+        }
+        
+        private void checkRepresentation(Model model, RelationRepresentation<D> representation) {
+                if(!model.getDataRepresentations().contains(representation)) {
+                        throw new IllegalArgumentException("Selected model does not contain representation " + representation + "!");
+                }
+        }
+        
+        public Model getModel() {
+                return model;
+        }
+        public RelationRepresentation<D> getRepresentation() {
+                return representation;
+        }
+        
+        public boolean get(Tuple t) {
+                D value = model.get(representation, t);
+                return value != representation.getDefaultValue() && filter.test(t,value);
+        }
+
+        public Iterable<Object[]> getAll() {
+                return (()->new CursorAsIterator<>(model.getAll(representation), mapping, filter));
+        }
+        
+        public static Object[] toTuple1Array(Tuple t) {
+                Object[] result = new Object[t.getSize()];
+                for(int i = 0; i<t.getSize(); i++) {
+                        result[i] = t.get(i);
+                }
+                return result;
+        }
+        public static <D> Object[] toTuple1ArrayPlusValue(Tuple t, D value) {
+                Object[] result = new Object[t.getSize()+1];
+                for(int i = 0; i<t.getSize(); i++) {
+                        result[i] = t.get(i);
+                }
+                result[t.getSize()] = value;
+                return result;
+        }
+}