1 files changed, 135 insertions, 0 deletions

diff --git a/subprojects/viatra-runtime-localsearch/src/main/java/tools/refinery/viatra/runtime/localsearch/operations/check/BinaryTransitiveClosureCheck.java b/subprojects/viatra-runtime-localsearch/src/main/java/tools/refinery/viatra/runtime/localsearch/operations/check/BinaryTransitiveClosureCheck.java
new file mode 100644
index 00000000..8f818542
--- /dev/null
+++ b/subprojects/viatra-runtime-localsearch/src/main/java/tools/refinery/viatra/runtime/localsearch/operations/check/BinaryTransitiveClosureCheck.java
@@ -0,0 +1,135 @@
+/*******************************************************************************
+ * Copyright (c) 2010-2013, Zoltan Ujhelyi, Istvan Rath and Daniel Varro
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-v20.html.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package tools.refinery.viatra.runtime.localsearch.operations.check;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Objects;
+import java.util.Queue;
+import java.util.Set;
+import java.util.function.Function;
+
+import tools.refinery.viatra.runtime.localsearch.MatchingFrame;
+import tools.refinery.viatra.runtime.localsearch.matcher.ISearchContext;
+import tools.refinery.viatra.runtime.localsearch.operations.CheckOperationExecutor;
+import tools.refinery.viatra.runtime.localsearch.operations.IPatternMatcherOperation;
+import tools.refinery.viatra.runtime.localsearch.operations.ISearchOperation;
+import tools.refinery.viatra.runtime.localsearch.operations.util.CallInformation;
+import tools.refinery.viatra.runtime.matchers.backend.IQueryResultProvider;
+import tools.refinery.viatra.runtime.matchers.tuple.Tuple;
+
+/**
+ * Checking for a transitive closure expressed as a local search pattern matcher. The matched pattern must have two
+ * parameters of the same model type.
+ * 
+ * @author Zoltan Ujhelyi
+ * @noextend This class is not intended to be subclassed by clients.
+ * @noinstantiate This class is not intended to be instantiated by clients.
+ * 
+ */
+public class BinaryTransitiveClosureCheck implements ISearchOperation, IPatternMatcherOperation {
+
+    private class Executor extends CheckOperationExecutor {
+        
+        @Override
+        public void onInitialize(MatchingFrame frame, ISearchContext context) {
+            super.onInitialize(frame, context);
+            matcher = context.getMatcher(information.getCallWithAdornment());
+            // Note: second parameter is NOT bound during execution, but the first is
+        }
+
+        @Override
+        protected boolean check(MatchingFrame frame, ISearchContext context) {
+            if (checkReflexive(frame)) {
+                return true;
+            }
+            
+            Object targetValue = frame.get(targetPosition);
+            Queue<Object> sourcesToEvaluate = new LinkedList<>();
+            sourcesToEvaluate.add(frame.get(sourcePosition));
+            Set<Object> sourceEvaluated = new HashSet<>();
+            final Object[] mappedFrame = new Object[] {null, null};
+            while (!sourcesToEvaluate.isEmpty()) {
+                Object currentValue = sourcesToEvaluate.poll();
+                sourceEvaluated.add(currentValue);
+                mappedFrame[0] = currentValue;
+                for (Tuple match : (Iterable<Tuple>) () -> matcher.getAllMatches(mappedFrame).iterator()) {
+                    Object foundTarget = match.get(1);
+                    if (targetValue.equals(foundTarget)) {
+                        return true;
+                    } else if (!sourceEvaluated.contains(foundTarget)) {
+                        sourcesToEvaluate.add(foundTarget);
+                    }
+                }
+            }
+            return false;
+        }
+        
+        protected boolean checkReflexive(MatchingFrame frame) {
+            return reflexive && Objects.equals(frame.get(sourcePosition), frame.get(targetPosition));
+        }
+        
+        @Override
+        public ISearchOperation getOperation() {
+            return BinaryTransitiveClosureCheck.this;
+        }
+    }
+    
+    private final CallInformation information; 
+    private IQueryResultProvider matcher;
+    private final int sourcePosition;
+    private final int targetPosition;
+    private final boolean reflexive;
+    
+    /**
+     * The source position will be matched in the called pattern to the first parameter; while target to the second.
+     * </p>
+     * <strong>NOTE</strong>: the reflexive check call does not include the parameter type checks; appropriate type checks should be
+     * added as necessary by the operation compiler.
+     * 
+     * @since 2.0
+     */
+    public BinaryTransitiveClosureCheck(CallInformation information, int sourcePosition, int targetPosition, boolean reflexive) {
+        super();
+        this.sourcePosition = sourcePosition;
+        this.targetPosition = targetPosition;
+        this.information = information;
+        this.reflexive = reflexive;
+    }
+    
+    @Override
+    public ISearchOperationExecutor createExecutor() {
+        return new Executor();
+    }
+
+    @Override
+    public String toString() {
+        return toString(Object::toString);
+    }
+    
+    @Override
+    public String toString(Function<Integer, String> variableMapping) {
+        String c = information.toString(variableMapping);
+        int p = c.indexOf('(');
+        String modifier = reflexive ? "*" : "+";
+        return "check     find "+c.substring(0, p)+ modifier +c.substring(p);
+    }
+
+    @Override
+    public List<Integer> getVariablePositions() {
+        return Arrays.asList(sourcePosition, targetPosition);
+    }
+
+    @Override
+    public CallInformation getCallInformation() {
+        return information;
+    }
+}