1 files changed, 721 insertions, 0 deletions
diff --git a/Tests/ca.mcgill.ecse.dslreasoner.standalone.test/src-gen/ca/mcgill/ecse/dslreasoner/standalone/test/yakindu/queries/Child.java b/Tests/ca.mcgill.ecse.dslreasoner.standalone.test/src-gen/ca/mcgill/ecse/dslreasoner/standalone/test/yakindu/queries/Child.java
new file mode 100644
index 00000000..9867c1ee
--- /dev/null
+++ b/Tests/ca.mcgill.ecse.dslreasoner.standalone.test/src-gen/ca/mcgill/ecse/dslreasoner/standalone/test/yakindu/queries/Child.java
@@ -0,0 +1,721 @@
+/**
+ * Generated from platform:/resource/ca.mcgill.ecse.dslreasoner.standalone.test/queries/ca/mcgill/ecse/dslreasoner/standalone/test/yakindu/queries/yakinduPatterns.vql
+ */
+package ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries;
+import ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.CompositeElement;
+import ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.Vertex;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Objects;
+import java.util.Optional;
+import java.util.Set;
+import java.util.function.Consumer;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+import org.apache.log4j.Logger;
+import org.eclipse.emf.ecore.EClass;
+import org.eclipse.viatra.query.runtime.api.IPatternMatch;
+import org.eclipse.viatra.query.runtime.api.IQuerySpecification;
+import org.eclipse.viatra.query.runtime.api.ViatraQueryEngine;
+import org.eclipse.viatra.query.runtime.api.impl.BaseGeneratedEMFPQuery;
+import org.eclipse.viatra.query.runtime.api.impl.BaseGeneratedEMFQuerySpecification;
+import org.eclipse.viatra.query.runtime.api.impl.BaseMatcher;
+import org.eclipse.viatra.query.runtime.api.impl.BasePatternMatch;
+import org.eclipse.viatra.query.runtime.emf.types.EClassTransitiveInstancesKey;
+import org.eclipse.viatra.query.runtime.emf.types.EStructuralFeatureInstancesKey;
+import org.eclipse.viatra.query.runtime.matchers.backend.QueryEvaluationHint;
+import org.eclipse.viatra.query.runtime.matchers.psystem.PBody;
+import org.eclipse.viatra.query.runtime.matchers.psystem.PVariable;
+import org.eclipse.viatra.query.runtime.matchers.psystem.basicdeferred.Equality;
+import org.eclipse.viatra.query.runtime.matchers.psystem.basicdeferred.ExportedParameter;
+import org.eclipse.viatra.query.runtime.matchers.psystem.basicenumerables.TypeConstraint;
+import org.eclipse.viatra.query.runtime.matchers.psystem.queries.PParameter;
+import org.eclipse.viatra.query.runtime.matchers.psystem.queries.PParameterDirection;
+import org.eclipse.viatra.query.runtime.matchers.psystem.queries.PVisibility;
+import org.eclipse.viatra.query.runtime.matchers.tuple.Tuple;
+import org.eclipse.viatra.query.runtime.matchers.tuple.Tuples;
+import org.eclipse.viatra.query.runtime.util.ViatraQueryLoggingUtil;
+/**
+ * A pattern-specific query specification that can instantiate Matcher in a type-safe way.
+ * 
+ * <p>Original source:
+ *         <code><pre>
+ *         ///////////////////////////////
+ *         // Extra
+ *         //
+ *         //{@literal @}Constraint(severity="error", message="error", key = {s})
+ *         //pattern SynchronizedRegionDoesNotHaveParent(s : Synchronization, v : Vertex) {
+ *         //   find transition(_, v, s);
+ *         //   neg find child(_,v);
+ *         //} or {
+ *         //   find transition(_, s, v);
+ *         //   neg find child(_,v);
+ *         //}
+ *         
+ *         pattern child(parent: CompositeElement, child: Vertex) {
+ *              CompositeElement.regions.vertices(parent, child);
+ *         }
+ * </pre></code>
+ * 
+ * @see Matcher
+ * @see Match
+ * 
+ */
+@SuppressWarnings("all")
+public final class Child extends BaseGeneratedEMFQuerySpecification<Child.Matcher> {
+  /**
+   * Pattern-specific match representation of the ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.child pattern,
+   * to be used in conjunction with {@link Matcher}.
+   * 
+   * <p>Class fields correspond to parameters of the pattern. Fields with value null are considered unassigned.
+   * Each instance is a (possibly partial) substitution of pattern parameters,
+   * usable to represent a match of the pattern in the result of a query,
+   * or to specify the bound (fixed) input parameters when issuing a query.
+   * 
+   * @see Matcher
+   * 
+   */
+  public static abstract class Match extends BasePatternMatch {
+    private CompositeElement fParent;
+    
+    private Vertex fChild;
+    
+    private static List<String> parameterNames = makeImmutableList("parent", "child");
+    
+    private Match(final CompositeElement pParent, final Vertex pChild) {
+      this.fParent = pParent;
+      this.fChild = pChild;
+    }
+    
+    @Override
+    public Object get(final String parameterName) {
+      if ("parent".equals(parameterName)) return this.fParent;
+      if ("child".equals(parameterName)) return this.fChild;
+      return null;
+    }
+    
+    public CompositeElement getParent() {
+      return this.fParent;
+    }
+    
+    public Vertex getChild() {
+      return this.fChild;
+    }
+    
+    @Override
+    public boolean set(final String parameterName, final Object newValue) {
+      if (!isMutable()) throw new java.lang.UnsupportedOperationException();
+      if ("parent".equals(parameterName) ) {
+          this.fParent = (CompositeElement) newValue;
+          return true;
+      }
+      if ("child".equals(parameterName) ) {
+          this.fChild = (Vertex) newValue;
+          return true;
+      }
+      return false;
+    }
+    
+    public void setParent(final CompositeElement pParent) {
+      if (!isMutable()) throw new java.lang.UnsupportedOperationException();
+      this.fParent = pParent;
+    }
+    
+    public void setChild(final Vertex pChild) {
+      if (!isMutable()) throw new java.lang.UnsupportedOperationException();
+      this.fChild = pChild;
+    }
+    
+    @Override
+    public String patternName() {
+      return "ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.child";
+    }
+    
+    @Override
+    public List<String> parameterNames() {
+      return Child.Match.parameterNames;
+    }
+    
+    @Override
+    public Object[] toArray() {
+      return new Object[]{fParent, fChild};
+    }
+    
+    @Override
+    public Child.Match toImmutable() {
+      return isMutable() ? newMatch(fParent, fChild) : this;
+    }
+    
+    @Override
+    public String prettyPrint() {
+      StringBuilder result = new StringBuilder();
+      result.append("\"parent\"=" + prettyPrintValue(fParent) + ", ");
+      result.append("\"child\"=" + prettyPrintValue(fChild));
+      return result.toString();
+    }
+    
+    @Override
+    public int hashCode() {
+      return Objects.hash(fParent, fChild);
+    }
+    
+    @Override
+    public boolean equals(final Object obj) {
+      if (this == obj)
+          return true;
+      if (obj == null) {
+          return false;
+      }
+      if ((obj instanceof Child.Match)) {
+          Child.Match other = (Child.Match) obj;
+          return Objects.equals(fParent, other.fParent) && Objects.equals(fChild, other.fChild);
+      } else {
+          // this should be infrequent
+          if (!(obj instanceof IPatternMatch)) {
+              return false;
+          }
+          IPatternMatch otherSig  = (IPatternMatch) obj;
+          return Objects.equals(specification(), otherSig.specification()) && Arrays.deepEquals(toArray(), otherSig.toArray());
+      }
+    }
+    
+    @Override
+    public Child specification() {
+      return Child.instance();
+    }
+    
+    /**
+     * Returns an empty, mutable match.
+     * Fields of the mutable match can be filled to create a partial match, usable as matcher input.
+     * 
+     * @return the empty match.
+     * 
+     */
+    public static Child.Match newEmptyMatch() {
+      return new Mutable(null, null);
+    }
+    
+    /**
+     * Returns a mutable (partial) match.
+     * Fields of the mutable match can be filled to create a partial match, usable as matcher input.
+     * 
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return the new, mutable (partial) match object.
+     * 
+     */
+    public static Child.Match newMutableMatch(final CompositeElement pParent, final Vertex pChild) {
+      return new Mutable(pParent, pChild);
+    }
+    
+    /**
+     * Returns a new (partial) match.
+     * This can be used e.g. to call the matcher with a partial match.
+     * <p>The returned match will be immutable. Use {@link #newEmptyMatch()} to obtain a mutable match object.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return the (partial) match object.
+     * 
+     */
+    public static Child.Match newMatch(final CompositeElement pParent, final Vertex pChild) {
+      return new Immutable(pParent, pChild);
+    }
+    
+    private static final class Mutable extends Child.Match {
+      Mutable(final CompositeElement pParent, final Vertex pChild) {
+        super(pParent, pChild);
+      }
+      
+      @Override
+      public boolean isMutable() {
+        return true;
+      }
+    }
+    
+    private static final class Immutable extends Child.Match {
+      Immutable(final CompositeElement pParent, final Vertex pChild) {
+        super(pParent, pChild);
+      }
+      
+      @Override
+      public boolean isMutable() {
+        return false;
+      }
+    }
+  }
+  
+  /**
+   * Generated pattern matcher API of the ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.child pattern,
+   * providing pattern-specific query methods.
+   * 
+   * <p>Use the pattern matcher on a given model via {@link #on(ViatraQueryEngine)},
+   * e.g. in conjunction with {@link ViatraQueryEngine#on(QueryScope)}.
+   * 
+   * <p>Matches of the pattern will be represented as {@link Match}.
+   * 
+   * <p>Original source:
+   * <code><pre>
+   * ///////////////////////////////
+   * // Extra
+   * //
+   * //{@literal @}Constraint(severity="error", message="error", key = {s})
+   * //pattern SynchronizedRegionDoesNotHaveParent(s : Synchronization, v : Vertex) {
+   * // find transition(_, v, s);
+   * // neg find child(_,v);
+   * //} or {
+   * // find transition(_, s, v);
+   * // neg find child(_,v);
+   * //}
+   * 
+   * pattern child(parent: CompositeElement, child: Vertex) {
+   *    CompositeElement.regions.vertices(parent, child);
+   * }
+   * </pre></code>
+   * 
+   * @see Match
+   * @see Child
+   * 
+   */
+  public static class Matcher extends BaseMatcher<Child.Match> {
+    /**
+     * Initializes the pattern matcher within an existing VIATRA Query engine.
+     * If the pattern matcher is already constructed in the engine, only a light-weight reference is returned.
+     * 
+     * @param engine the existing VIATRA Query engine in which this matcher will be created.
+     * @throws ViatraQueryRuntimeException if an error occurs during pattern matcher creation
+     * 
+     */
+    public static Child.Matcher on(final ViatraQueryEngine engine) {
+      // check if matcher already exists
+      Matcher matcher = engine.getExistingMatcher(querySpecification());
+      if (matcher == null) {
+          matcher = (Matcher)engine.getMatcher(querySpecification());
+      }
+      return matcher;
+    }
+    
+    /**
+     * @throws ViatraQueryRuntimeException if an error occurs during pattern matcher creation
+     * @return an initialized matcher
+     * @noreference This method is for internal matcher initialization by the framework, do not call it manually.
+     * 
+     */
+    public static Child.Matcher create() {
+      return new Matcher();
+    }
+    
+    private final static int POSITION_PARENT = 0;
+    
+    private final static int POSITION_CHILD = 1;
+    
+    private final static Logger LOGGER = ViatraQueryLoggingUtil.getLogger(Child.Matcher.class);
+    
+    /**
+     * Initializes the pattern matcher within an existing VIATRA Query engine.
+     * If the pattern matcher is already constructed in the engine, only a light-weight reference is returned.
+     * 
+     * @param engine the existing VIATRA Query engine in which this matcher will be created.
+     * @throws ViatraQueryRuntimeException if an error occurs during pattern matcher creation
+     * 
+     */
+    private Matcher() {
+      super(querySpecification());
+    }
+    
+    /**
+     * Returns the set of all matches of the pattern that conform to the given fixed values of some parameters.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return matches represented as a Match object.
+     * 
+     */
+    public Collection<Child.Match> getAllMatches(final CompositeElement pParent, final Vertex pChild) {
+      return rawStreamAllMatches(new Object[]{pParent, pChild}).collect(Collectors.toSet());
+    }
+    
+    /**
+     * Returns a stream of all matches of the pattern that conform to the given fixed values of some parameters.
+     * </p>
+     * <strong>NOTE</strong>: It is important not to modify the source model while the stream is being processed.
+     * If the match set of the pattern changes during processing, the contents of the stream is <strong>undefined</strong>.
+     * In such cases, either rely on {@link #getAllMatches()} or collect the results of the stream in end-user code.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return a stream of matches represented as a Match object.
+     * 
+     */
+    public Stream<Child.Match> streamAllMatches(final CompositeElement pParent, final Vertex pChild) {
+      return rawStreamAllMatches(new Object[]{pParent, pChild});
+    }
+    
+    /**
+     * Returns an arbitrarily chosen match of the pattern that conforms to the given fixed values of some parameters.
+     * Neither determinism nor randomness of selection is guaranteed.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return a match represented as a Match object, or null if no match is found.
+     * 
+     */
+    public Optional<Child.Match> getOneArbitraryMatch(final CompositeElement pParent, final Vertex pChild) {
+      return rawGetOneArbitraryMatch(new Object[]{pParent, pChild});
+    }
+    
+    /**
+     * Indicates whether the given combination of specified pattern parameters constitute a valid pattern match,
+     * under any possible substitution of the unspecified parameters (if any).
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return true if the input is a valid (partial) match of the pattern.
+     * 
+     */
+    public boolean hasMatch(final CompositeElement pParent, final Vertex pChild) {
+      return rawHasMatch(new Object[]{pParent, pChild});
+    }
+    
+    /**
+     * Returns the number of all matches of the pattern that conform to the given fixed values of some parameters.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return the number of pattern matches found.
+     * 
+     */
+    public int countMatches(final CompositeElement pParent, final Vertex pChild) {
+      return rawCountMatches(new Object[]{pParent, pChild});
+    }
+    
+    /**
+     * Executes the given processor on an arbitrarily chosen match of the pattern that conforms to the given fixed values of some parameters.
+     * Neither determinism nor randomness of selection is guaranteed.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @param processor the action that will process the selected match.
+     * @return true if the pattern has at least one match with the given parameter values, false if the processor was not invoked
+     * 
+     */
+    public boolean forOneArbitraryMatch(final CompositeElement pParent, final Vertex pChild, final Consumer<? super Child.Match> processor) {
+      return rawForOneArbitraryMatch(new Object[]{pParent, pChild}, processor);
+    }
+    
+    /**
+     * Returns a new (partial) match.
+     * This can be used e.g. to call the matcher with a partial match.
+     * <p>The returned match will be immutable. Use {@link #newEmptyMatch()} to obtain a mutable match object.
+     * @param pParent the fixed value of pattern parameter parent, or null if not bound.
+     * @param pChild the fixed value of pattern parameter child, or null if not bound.
+     * @return the (partial) match object.
+     * 
+     */
+    public Child.Match newMatch(final CompositeElement pParent, final Vertex pChild) {
+      return Child.Match.newMatch(pParent, pChild);
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    protected Stream<CompositeElement> rawStreamAllValuesOfparent(final Object[] parameters) {
+      return rawStreamAllValues(POSITION_PARENT, parameters).map(CompositeElement.class::cast);
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Set<CompositeElement> getAllValuesOfparent() {
+      return rawStreamAllValuesOfparent(emptyArray()).collect(Collectors.toSet());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Stream<CompositeElement> streamAllValuesOfparent() {
+      return rawStreamAllValuesOfparent(emptyArray());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * </p>
+     * <strong>NOTE</strong>: It is important not to modify the source model while the stream is being processed.
+     * If the match set of the pattern changes during processing, the contents of the stream is <strong>undefined</strong>.
+     * In such cases, either rely on {@link #getAllMatches()} or collect the results of the stream in end-user code.
+     *      
+     * @return the Stream of all values or empty set if there are no matches
+     * 
+     */
+    public Stream<CompositeElement> streamAllValuesOfparent(final Child.Match partialMatch) {
+      return rawStreamAllValuesOfparent(partialMatch.toArray());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * </p>
+     * <strong>NOTE</strong>: It is important not to modify the source model while the stream is being processed.
+     * If the match set of the pattern changes during processing, the contents of the stream is <strong>undefined</strong>.
+     * In such cases, either rely on {@link #getAllMatches()} or collect the results of the stream in end-user code.
+     *      
+     * @return the Stream of all values or empty set if there are no matches
+     * 
+     */
+    public Stream<CompositeElement> streamAllValuesOfparent(final Vertex pChild) {
+      return rawStreamAllValuesOfparent(new Object[]{null, pChild});
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Set<CompositeElement> getAllValuesOfparent(final Child.Match partialMatch) {
+      return rawStreamAllValuesOfparent(partialMatch.toArray()).collect(Collectors.toSet());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for parent.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Set<CompositeElement> getAllValuesOfparent(final Vertex pChild) {
+      return rawStreamAllValuesOfparent(new Object[]{null, pChild}).collect(Collectors.toSet());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    protected Stream<Vertex> rawStreamAllValuesOfchild(final Object[] parameters) {
+      return rawStreamAllValues(POSITION_CHILD, parameters).map(Vertex.class::cast);
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Set<Vertex> getAllValuesOfchild() {
+      return rawStreamAllValuesOfchild(emptyArray()).collect(Collectors.toSet());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Stream<Vertex> streamAllValuesOfchild() {
+      return rawStreamAllValuesOfchild(emptyArray());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * </p>
+     * <strong>NOTE</strong>: It is important not to modify the source model while the stream is being processed.
+     * If the match set of the pattern changes during processing, the contents of the stream is <strong>undefined</strong>.
+     * In such cases, either rely on {@link #getAllMatches()} or collect the results of the stream in end-user code.
+     *      
+     * @return the Stream of all values or empty set if there are no matches
+     * 
+     */
+    public Stream<Vertex> streamAllValuesOfchild(final Child.Match partialMatch) {
+      return rawStreamAllValuesOfchild(partialMatch.toArray());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * </p>
+     * <strong>NOTE</strong>: It is important not to modify the source model while the stream is being processed.
+     * If the match set of the pattern changes during processing, the contents of the stream is <strong>undefined</strong>.
+     * In such cases, either rely on {@link #getAllMatches()} or collect the results of the stream in end-user code.
+     *      
+     * @return the Stream of all values or empty set if there are no matches
+     * 
+     */
+    public Stream<Vertex> streamAllValuesOfchild(final CompositeElement pParent) {
+      return rawStreamAllValuesOfchild(new Object[]{pParent, null});
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Set<Vertex> getAllValuesOfchild(final Child.Match partialMatch) {
+      return rawStreamAllValuesOfchild(partialMatch.toArray()).collect(Collectors.toSet());
+    }
+    
+    /**
+     * Retrieve the set of values that occur in matches for child.
+     * @return the Set of all values or empty set if there are no matches
+     * 
+     */
+    public Set<Vertex> getAllValuesOfchild(final CompositeElement pParent) {
+      return rawStreamAllValuesOfchild(new Object[]{pParent, null}).collect(Collectors.toSet());
+    }
+    
+    @Override
+    protected Child.Match tupleToMatch(final Tuple t) {
+      try {
+          return Child.Match.newMatch((CompositeElement) t.get(POSITION_PARENT), (Vertex) t.get(POSITION_CHILD));
+      } catch(ClassCastException e) {
+          LOGGER.error("Element(s) in tuple not properly typed!",e);
+          return null;
+      }
+    }
+    
+    @Override
+    protected Child.Match arrayToMatch(final Object[] match) {
+      try {
+          return Child.Match.newMatch((CompositeElement) match[POSITION_PARENT], (Vertex) match[POSITION_CHILD]);
+      } catch(ClassCastException e) {
+          LOGGER.error("Element(s) in array not properly typed!",e);
+          return null;
+      }
+    }
+    
+    @Override
+    protected Child.Match arrayToMatchMutable(final Object[] match) {
+      try {
+          return Child.Match.newMutableMatch((CompositeElement) match[POSITION_PARENT], (Vertex) match[POSITION_CHILD]);
+      } catch(ClassCastException e) {
+          LOGGER.error("Element(s) in array not properly typed!",e);
+          return null;
+      }
+    }
+    
+    /**
+     * @return the singleton instance of the query specification of this pattern
+     * @throws ViatraQueryRuntimeException if the pattern definition could not be loaded
+     * 
+     */
+    public static IQuerySpecification<Child.Matcher> querySpecification() {
+      return Child.instance();
+    }
+  }
+  
+  private Child() {
+    super(GeneratedPQuery.INSTANCE);
+  }
+  
+  /**
+   * @return the singleton instance of the query specification
+   * @throws ViatraQueryRuntimeException if the pattern definition could not be loaded
+   * 
+   */
+  public static Child instance() {
+    try{
+        return LazyHolder.INSTANCE;
+    } catch (ExceptionInInitializerError err) {
+        throw processInitializerError(err);
+    }
+  }
+  
+  @Override
+  protected Child.Matcher instantiate(final ViatraQueryEngine engine) {
+    return Child.Matcher.on(engine);
+  }
+  
+  @Override
+  public Child.Matcher instantiate() {
+    return Child.Matcher.create();
+  }
+  
+  @Override
+  public Child.Match newEmptyMatch() {
+    return Child.Match.newEmptyMatch();
+  }
+  
+  @Override
+  public Child.Match newMatch(final Object... parameters) {
+    return Child.Match.newMatch((ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.CompositeElement) parameters[0], (ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.Vertex) parameters[1]);
+  }
+  
+  /**
+   * Inner class allowing the singleton instance of {@link JvmGenericType: ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.Child (visibility: PUBLIC, simpleName: Child, identifier: ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.Child, deprecated: <unset>) (abstract: false, static: false, final: true, packageName: ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries) (interface: false, strictFloatingPoint: false, anonymous: false)} to be created 
+   *     <b>not</b> at the class load time of the outer class, 
+   *     but rather at the first call to {@link JvmGenericType: ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.Child (visibility: PUBLIC, simpleName: Child, identifier: ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.Child, deprecated: <unset>) (abstract: false, static: false, final: true, packageName: ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries) (interface: false, strictFloatingPoint: false, anonymous: false)#instance()}.
+   * 
+   * <p> This workaround is required e.g. to support recursion.
+   * 
+   */
+  private static class LazyHolder {
+    private final static Child INSTANCE = new Child();
+    
+    /**
+     * Statically initializes the query specification <b>after</b> the field {@link #INSTANCE} is assigned.
+     * This initialization order is required to support indirect recursion.
+     * 
+     * <p> The static initializer is defined using a helper field to work around limitations of the code generator.
+     * 
+     */
+    private final static Object STATIC_INITIALIZER = ensureInitialized();
+    
+    public static Object ensureInitialized() {
+      INSTANCE.ensureInitializedInternal();
+      return null;
+    }
+  }
+  
+  private static class GeneratedPQuery extends BaseGeneratedEMFPQuery {
+    private final static Child.GeneratedPQuery INSTANCE = new GeneratedPQuery();
+    
+    private final PParameter parameter_parent = new PParameter("parent", "ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.CompositeElement", new EClassTransitiveInstancesKey((EClass)getClassifierLiteralSafe("YakinduMetamodel", "CompositeElement")), PParameterDirection.INOUT);
+    
+    private final PParameter parameter_child = new PParameter("child", "ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.Vertex", new EClassTransitiveInstancesKey((EClass)getClassifierLiteralSafe("YakinduMetamodel", "Vertex")), PParameterDirection.INOUT);
+    
+    private final List<PParameter> parameters = Arrays.asList(parameter_parent, parameter_child);
+    
+    private GeneratedPQuery() {
+      super(PVisibility.PUBLIC);
+    }
+    
+    @Override
+    public String getFullyQualifiedName() {
+      return "ca.mcgill.ecse.dslreasoner.standalone.test.yakindu.queries.child";
+    }
+    
+    @Override
+    public List<String> getParameterNames() {
+      return Arrays.asList("parent","child");
+    }
+    
+    @Override
+    public List<PParameter> getParameters() {
+      return parameters;
+    }
+    
+    @Override
+    public Set<PBody> doGetContainedBodies() {
+      setEvaluationHints(new QueryEvaluationHint(null, QueryEvaluationHint.BackendRequirement.UNSPECIFIED));
+      Set<PBody> bodies = new LinkedHashSet<>();
+      {
+          PBody body = new PBody(this);
+          PVariable var_parent = body.getOrCreateVariableByName("parent");
+          PVariable var_child = body.getOrCreateVariableByName("child");
+          new TypeConstraint(body, Tuples.flatTupleOf(var_parent), new EClassTransitiveInstancesKey((EClass)getClassifierLiteral("YakinduMetamodel", "CompositeElement")));
+          new TypeConstraint(body, Tuples.flatTupleOf(var_child), new EClassTransitiveInstancesKey((EClass)getClassifierLiteral("YakinduMetamodel", "Vertex")));
+          body.setSymbolicParameters(Arrays.<ExportedParameter>asList(
+             new ExportedParameter(body, var_parent, parameter_parent),
+             new ExportedParameter(body, var_child, parameter_child)
+          ));
+          //    CompositeElement.regions.vertices(parent, child)
+          new TypeConstraint(body, Tuples.flatTupleOf(var_parent), new EClassTransitiveInstancesKey((EClass)getClassifierLiteral("YakinduMetamodel", "CompositeElement")));
+          PVariable var__virtual_0_ = body.getOrCreateVariableByName(".virtual{0}");
+          new TypeConstraint(body, Tuples.flatTupleOf(var_parent, var__virtual_0_), new EStructuralFeatureInstancesKey(getFeatureLiteral("YakinduMetamodel", "CompositeElement", "regions")));
+          new TypeConstraint(body, Tuples.flatTupleOf(var__virtual_0_), new EClassTransitiveInstancesKey((EClass)getClassifierLiteral("YakinduMetamodel", "Region")));
+          PVariable var__virtual_1_ = body.getOrCreateVariableByName(".virtual{1}");
+          new TypeConstraint(body, Tuples.flatTupleOf(var__virtual_0_, var__virtual_1_), new EStructuralFeatureInstancesKey(getFeatureLiteral("YakinduMetamodel", "Region", "vertices")));
+          new TypeConstraint(body, Tuples.flatTupleOf(var__virtual_1_), new EClassTransitiveInstancesKey((EClass)getClassifierLiteral("YakinduMetamodel", "Vertex")));
+          new Equality(body, var__virtual_1_, var_child);
+          bodies.add(body);
+      }
+      return bodies;
+    }
+  }
+}