Gremlin DSLs in Java with DSE Graph

dr.patients("55600064").                 // find a patient by id

   prescriptions(Rx.CURRENT).            // get prescriptions they are currently prescribed

     consider("lipitor", "40mg").        // for purpose of analysis add lipitor to that list

     consider("lunesta", "1mg").         // for purpose of analysis add lunesta to that list

   interactions(Type.DRUG, Level.SEVERE) // find possible drug interactions that are severe

schema.vertexLabel("movie").properties("movieId","title","year","duration","country","production").create();

schema.vertexLabel("person").properties("personId","name").create();

schema.edgeLabel("actor").connection("movie","person").create();

g.V().has("movie", "title","Young Guns").out("actor")

killr.movies("Young Guns").actors()

public class KillrVideoTraversalSource extends GraphTraversalSource {

  public KillrVideoTraversalSource(Graph graph) {

    super(graph);

  }

  public KillrVideoTraversalSource(Graph graph, TraversalStrategies strategies) {

    super(graph, strategies);

  }

  public KillrVideoTraversal<Vertex, Vertex> movies(String title) {

    // implementation omitted for brevity

  }

}

killr.movies("Young Guns")

killr.movies("Young Guns").out("actors").in("actors")

// not possible because actors() is not a method GraphTraversal which is returned by in()

killr.movies("Young Guns").out("actors").in("actors").actors()

// possible with casting which isn't ideal

((KillrVideoTraversal) killr.movies("Young Guns").out("actors").in("actors")).actors()

@GremlinDsl

public interface KillrVideoTraversalDsl<S, E> extends GraphTraversal.Admin<S, E> {

}

@GremlinDsl(traversalSource = "com.killrvideo.KillrVideoTraversalSourceDsl")

public interface KillrVideoTraversalDsl<S, E> extends GraphTraversal.Admin<S, E> {

}

public class KillrVideoTraversalSourceDsl extends GraphTraversalSource {

    public KillrVideoTraversalSourceDsl(final Graph graph, final TraversalStrategies traversalStrategies) {

        super(graph, traversalStrategies);

    }

    public KillrVideoTraversalSourceDsl(final Graph graph) {

        super(graph);

    }

}

@GremlinDsl(traversalSource = "com.killrvideo.KillrVideoTraversalSourceDsl")

public interface KillrVideoTraversalDsl<S, E> extends GraphTraversal.Admin<S, E> {

    public default GraphTraversal<S, Vertex> actors() {

        return out("actor").hasLabel("person");

    }

}

public class KillrVideoTraversalSourceDsl extends GraphTraversalSource {

    public KillrVideoTraversalSourceDsl(final Graph graph, final TraversalStrategies traversalStrategies) {

        super(graph, traversalStrategies);

    }

    public KillrVideoTraversalSourceDsl(final Graph graph) {

        super(graph);

    }

     public GraphTraversal<Vertex, Vertex> movies(String... titles) {

       GraphTraversal traversal = this.clone().V();       

       traversal = traversal.hasLabel("movie");

        if (titles.length == 1)

            traversal = traversal.has("title", titles[0]);

        else if (titles.length > 1)

            traversal = traversal.has("title", P.within(titles));

        return traversal;

    }

}

DseCluster dseCluster = DseCluster.builder()

                                  .addContactPoint("127.0.0.1")

                                  .build();

DseSession dseSession = dseCluster.connect();

KillrVideoTraversalSource killr = DseGraph.traversal(dseSession,

        new GraphOptions().setGraphName("killrvideo"), KillrVideoTraversalSource.class)

killr.movies("Young Guns").actors().values("name").toList();

public interface KillrVideoTraversal<S, E> extends KillrVideoTraversalDsl<S, E> {

  @Override

  default KillrVideoTraversal<S, Vertex> actors() {

    return (KillrVideoTraversal) KillrVideoTraversalDsl.super.actors();

  }

  // other DSL steps from the full project omitted for brevity

  @Override

  default KillrVideoTraversal<S, Vertex> out(String... edgeLabels) {

    return (KillrVideoTraversal) KillrVideoTraversalDsl.super.out(edgeLabels);

  }

  // remaining Graph steps omitted for brevity

}

public class KillrVideoTraversalSource extends KillrVideoTraversalSourceDsl {

  public KillrVideoTraversalSource(Graph graph) {

    super(graph);

  }

  public KillrVideoTraversalSource(Graph graph, TraversalStrategies strategies) {

    super(graph, strategies);

  }

  @Override

  public KillrVideoTraversal<Vertex, Vertex> movies(String title, String... additionalTitles) {

    KillrVideoTraversalSource clone = this.clone();

    return new DefaultKillrVideoTraversal (clone, super.movies(title,additionalTitles).asAdmin());

  }

  // remaining DSL steps omitted for brevity

  @Override

  public KillrVideoTraversalSource withStrategies(TraversalStrategy... traversalStrategies) {

    return (KillrVideoTraversalSource) super.withStrategies(traversalStrategies);

  }

  // remaining Graph steps omitted for brevity

}

killr.movie("m100000", "Manos: The Hands of Fate", "USA", "Sun City Films", 1966, 70).

        ensure(actor("p1000000", "Tom Neyman")).

        ensure(actor("p1000001", "John Reynolds")).

        ensure(actor("p1000002", "Diane Mahree"))

g.V().

  has("movie", "movieId", "m100000").

  fold().

  coalesce(

    __.unfold(),

    __.addV("movie").property("movieId", "m100000")).

  property("title", "Manos: The Hands of Fate").

  property("country", "USA").

  property("production", "Sun City Films").

  property("year", 1966).

  property("duration", 70).as("^movie").

  sideEffect(coalesce(out("actor").has("person", "personId", "p1000000"),

                      coalesce(V().has("person", "personId", "p1000000"),

                               addV("person").property("personId", "p1000000")).

                      property("name", "Tom Neyman").

                      addE("actor").

                        from("^movie").

                      inV())).

  sideEffect(coalesce(out("actor").has("person", "personId", "p1000001"),

                      coalesce(V().has("person", "personId", "p1000001"),

                               addV("person").property("personId", "p1000001")).

                      property("name", "John Reynolds").

                      addE("actor").

                        from("^movie").

                      inV())).

  sideEffect(coalesce(out("actor").has("person", "personId", "p1000002"),

                      coalesce(V().has("person", "personId", "p1000002"),

                               addV("person").property("personId", "p1000002")).

                      property("name", "Diane Mahree").

                      addE("actor").

                        from("^movie").

                      inV())).

dr.patients("55600064").                 // find a patient by id

   prescriptions(Rx.CURRENT).            // get prescriptions they are currently prescribed

     consider("lipitor", "40mg").        // for purpose of analysis add lipitor to that list

     consider("lunesta", "1mg").         // for purpose of analysis add lunesta to that list

   interactions(Type.DRUG, Level.SEVERE) // find possible drug interactions that are severe