org.neo4j.kernel.impl.traversal
Class TraversalDescriptionImpl

java.lang.Object
  org.neo4j.kernel.impl.traversal.TraversalDescriptionImpl

All Implemented Interfaces:

TraversalDescription

public final class TraversalDescriptionImpl
extends Object
implements TraversalDescription

Constructor Summary

TraversalDescriptionImpl()

Method Summary

TraversalDescription	breadthFirst() A convenience method for TraversalDescription.order(BranchOrderingPolicy) where a "preorder breadth first" selector is used.
TraversalDescription	depthFirst() A convenience method for TraversalDescription.order(BranchOrderingPolicy) where a "preorder depth first" selector is used.
TraversalDescription	evaluator(Evaluator evaluator) NOTE: Replaces TraversalDescription.filter(Predicate) and TraversalDescription.prune(PruneEvaluator).
TraversalDescription	expand(RelationshipExpander expander) Sets the RelationshipExpander as the expander of relationships, discarding all previous calls to TraversalDescription.relationships(RelationshipType) and TraversalDescription.relationships(RelationshipType, Direction).
TraversalDescription	filter(Predicate<Path> filter) Adds filter to the list of filters to use, i.e.
TraversalDescription	order(BranchOrderingPolicy selector) Sets the BranchOrderingPolicy to use.
TraversalDescription	prune(PruneEvaluator pruning) Adds pruning to the list of PruneEvaluators which are used to prune the traversal.
TraversalDescription	relationships(RelationshipType type) Adds type to the list of relationship types to traverse.
TraversalDescription	relationships(RelationshipType type, Direction direction) Adds type to the list of relationship types to traverse in the given direction.
Traverser	traverse(Node startNode) Traverse from startNode based on all the rules and behavior in this description.
TraversalDescription	uniqueness(UniquenessFactory uniqueness) Sets the UniquenessFactory for creating the UniquenessFilter to use.
TraversalDescription	uniqueness(UniquenessFactory uniqueness, Object parameter) Sets the UniquenessFactory for creating the UniquenessFilter to use.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TraversalDescriptionImpl

public TraversalDescriptionImpl()

Method Detail

traverse

public Traverser traverse(Node startNode)

Description copied from interface: TraversalDescription

Traverse from startNode based on all the rules and behavior in this description. A Traverser is returned which is used to step through the graph and getting results back. The traversal is not guaranteed to start before the Traverser is used.

Specified by:

traverse in interface TraversalDescription

Parameters:

startNode - the Node to start the traversal from.

Returns:

a Traverser used to step through the graph and to get results from.

uniqueness

public TraversalDescription uniqueness(UniquenessFactory uniqueness)

Description copied from interface: TraversalDescription

Sets the UniquenessFactory for creating the UniquenessFilter to use.

Specified by:

uniqueness in interface TraversalDescription

Parameters:

uniqueness - the UniquenessFactory the creator of the desired UniquenessFilter to use.

Returns:

a new traversal description with the new modifications.

uniqueness

public TraversalDescription uniqueness(UniquenessFactory uniqueness,
                                       Object parameter)

Description copied from interface: TraversalDescription

Sets the UniquenessFactory for creating the UniquenessFilter to use. It also accepts an extra parameter which is mandatory for certain uniqueness's, f.ex Uniqueness.NODE_RECENT.

Specified by:

uniqueness in interface TraversalDescription

Parameters:

uniqueness - the UniquenessFactory the creator of the desired UniquenessFilter to use.

Returns:

a new traversal description with the new modifications.

prune

public TraversalDescription prune(PruneEvaluator pruning)

Description copied from interface: TraversalDescription

Adds pruning to the list of PruneEvaluators which are used to prune the traversal. The semantics for many prune evaluators is that if any one of the added prune evaluators returns true it's considered OK to prune there.

Specified by:

prune in interface TraversalDescription

Parameters:

pruning - the PruneEvaluator to add to the list of prune evaluators to use.

Returns:

a new traversal description with the new modifications.

filter

public TraversalDescription filter(Predicate<Path> filter)

Description copied from interface: TraversalDescription

Adds filter to the list of filters to use, i.e. a filter to decide which positions are OK to return or not. Each position is represented by a Path from the start node of the traversal to the current node. The current node is the Path.endNode() of the path. Each Path must be accepted by all added filter for it to be returned from the traverser. For adding a filter which returns paths accepted by any filters, see Traversal.returnAcceptedByAny(Predicate...) for convenience.

Specified by:

filter in interface TraversalDescription

Parameters:

filter - the Predicate to add to the list of filters.

Returns:

a new traversal description with the new modifications.

evaluator

public TraversalDescription evaluator(Evaluator evaluator)

Description copied from interface: TraversalDescription

NOTE: Replaces TraversalDescription.filter(Predicate) and TraversalDescription.prune(PruneEvaluator). Adds evaluator to the list of evaluators which will control the behaviour of the traversal. Each Evaluator can decide whether or not to include a position in the traverser result, i.e. return it from the Traverser iterator and also whether to continue down that path or to prune, so that the traverser won't continue further down that path. Multiple Evaluators can be added. For a path to be included in the result, all evaluators must agree to include it, i.e. returning either Evaluation.INCLUDE_AND_CONTINUE or Evaluation.INCLUDE_AND_PRUNE. For making the traversal continue down that path all evaluators must agree to continue from that path, i.e. returning either Evaluation.INCLUDE_AND_CONTINUE or Evaluation.EXCLUDE_AND_CONTINUE.

Specified by:

evaluator in interface TraversalDescription

Returns:

a new traversal description with the new modifications.

order

public TraversalDescription order(BranchOrderingPolicy selector)

Description copied from interface: TraversalDescription

Sets the BranchOrderingPolicy to use. A BranchSelector is the basic decisions in the traversal of "where to go next". Examples of default implementations are "breadth first" and "depth first", which can be set with convenience methods TraversalDescription.breadthFirst() and TraversalDescription.depthFirst().

Specified by:

order in interface TraversalDescription

Parameters:

selector - the factory which creates the BranchSelector to use with the traversal.

Returns:

a new traversal description with the new modifications.

depthFirst

public TraversalDescription depthFirst()

Description copied from interface: TraversalDescription

A convenience method for TraversalDescription.order(BranchOrderingPolicy) where a "preorder depth first" selector is used. Positions which are deeper than the current position will be returned before positions on the same depth. See http://en.wikipedia.org/wiki/Depth-first_search

Specified by:

depthFirst in interface TraversalDescription

Returns:

a new traversal description with the new modifications.

breadthFirst

public TraversalDescription breadthFirst()

Description copied from interface: TraversalDescription

A convenience method for TraversalDescription.order(BranchOrderingPolicy) where a "preorder breadth first" selector is used. All positions with the same depth will be returned before advancing to the next depth. See http://en.wikipedia.org/wiki/Breadth-first_search

Specified by:

breadthFirst in interface TraversalDescription

Returns:

a new traversal description with the new modifications.

relationships

public TraversalDescription relationships(RelationshipType type)

Description copied from interface: TraversalDescription

Adds type to the list of relationship types to traverse. There's no priority or order in which types to traverse.

Specified by:

relationships in interface TraversalDescription

Parameters:

type - the RelationshipType to add to the list of types to traverse.

Returns:

a new traversal description with the new modifications.

relationships

public TraversalDescription relationships(RelationshipType type,
                                          Direction direction)

Description copied from interface: TraversalDescription

Adds type to the list of relationship types to traverse in the given direction. There's no priority or order in which types to traverse.

Specified by:

relationships in interface TraversalDescription

Parameters:

type - the RelationshipType to add to the list of types to traverse.

direction - the Direction to traverse this type of relationship in.

Returns:

a new traversal description with the new modifications.

expand

public TraversalDescription expand(RelationshipExpander expander)

Description copied from interface: TraversalDescription

Sets the RelationshipExpander as the expander of relationships, discarding all previous calls to TraversalDescription.relationships(RelationshipType) and TraversalDescription.relationships(RelationshipType, Direction).

Specified by:

expand in interface TraversalDescription

Parameters:

expander - the RelationshipExpander to use.

Returns:

a new traversal description with the new modifications.