Package org.neo4j.graphdb.traversal

Interface TraversalBranch

All Superinterfaces:
Iterable<Entity>, Path
public interface TraversalBranch extends Path
Represents a position and a PathExpander with a traversal context, for example parent and an iterator of relationships to go next. It's a base to write a BranchSelector on top of.

  • Method Details

    • parent

      TraversalBranch parent()
      The parent expansion source which created this TraversalBranch.
      Returns:
      the parent of this expansion source.

    • next

      TraversalBranch next(PathExpander expander, TraversalContext metadata)
      Returns the next expansion source from the expanded relationships from the current node.
      Parameters:
      expander - an expander to decide which relationships to follow
      metadata - the context of the traversal
      Returns:
      the next expansion source from this expansion source.

    • expanded

      int expanded()
      Returns the number of relationships this expansion source has expanded. In this count isn't included the relationship which led to coming here (since that could also be traversed, although skipped, when expanding this source).
      Returns:
      the number of relationships this expansion source has expanded.

    • prune

      void prune()
      Explicitly tell this branch to be pruned so that consecutive calls to next(PathExpander, TraversalContext) is guaranteed to return null.

    • continues

      boolean continues()
      Returns:
      whether or not the traversal should continue further along this branch.

    • includes

      boolean includes()
      Returns:
      whether or not this branch (the Path representation of this branch at least) should be included in the result of this traversal, i.e. returned as one of the Paths from f.ex. TraversalDescription.traverse(org.neo4j.graphdb.Node...)

    • evaluation

      void evaluation(Evaluation eval)
      Can change evaluation outcome in a negative direction. For example to force pruning.
      Parameters:
      eval - the Evaluation to AND with the current evaluation.

    • initialize

      void initialize(PathExpander expander, TraversalContext metadata)
      Initializes this TraversalBranch, the relationship iterator, Evaluation etc.
      Parameters:
      expander - PathExpander to use for getting relationships.
      metadata - TraversalContext to update on progress.

    • state

      Object state()
      Returns the state associated with this branch. Why is this of type Object? The state object type only exists when specifying the expander in the TraversalDescription, not anywhere else. So in the internals of the traversal the state type is unknown and ignored.
      Returns:
      the state associated with this branch.