org.neo4j.graphdb.traversal

Class Evaluators

java.lang.Object

org.neo4j.graphdb.traversal.Evaluators

public abstract class Evaluators
extends Object

Common Evaluators useful during common traversals.

See Also:

Evaluator, TraversalDescription

Constructor Summary

Constructors

Constructor and Description
Evaluators()

Method Summary

Modifier and Type	Method and Description
static <STATE> PathEvaluator<STATE>	all()
static <STATE> PathEvaluator<STATE>	atDepth(int depth) Returns an Evaluator which only includes positions at depth and prunes everything deeper than that.
static <STATE> PathEvaluator<STATE>	endNodeIs(Evaluation evaluationIfMatch, Evaluation evaluationIfNoMatch, Node... possibleEndNodes) An Evaluator which will return evaluationIfMatch if Path.endNode() for a given path is any of nodes, else evaluationIfNoMatch.
static <STATE> PathEvaluator<STATE>	endNodeIsAtDepth(int depth, Node... possibleEndNodes) Returns Evaluators for paths with the specified depth and with an end node from the list of possibleEndNodes.
static PathEvaluator	excludeStartPosition()
static <STATE> PathEvaluator<STATE>	fromDepth(int depth) Returns an Evaluator which only includes positions from depth and deeper and never prunes anything.
static <STATE> PathEvaluator<STATE>	includeIfAcceptedByAny(Evaluator... evaluators) Whereas adding Evaluators to a TraversalDescription puts those evaluators in AND-mode this can group many evaluators in OR-mode.
static <STATE> PathEvaluator<STATE>	includeIfAcceptedByAny(PathEvaluator... evaluators) Whereas adding Evaluators to a TraversalDescription puts those evaluators in AND-mode this can group many evaluators in OR-mode.
static <STATE> PathEvaluator<STATE>	includeIfContainsAll(Node... nodes) Evaluator which decides to include a Path if all the nodes exist in it.
static <STATE> PathEvaluator<STATE>	includeWhereEndNodeIs(Node... nodes) Include paths with the specified end nodes.
static <STATE> PathEvaluator<STATE>	includeWhereLastRelationshipTypeIs(RelationshipType type, RelationshipType... orAnyOfTheseTypes)
static <STATE> PathEvaluator<STATE>	includingDepths(int minDepth, int maxDepth) Returns an Evaluator which only includes positions between depths minDepth and maxDepth.
static <STATE> PathEvaluator<STATE>	lastRelationshipTypeIs(Evaluation evaluationIfMatch, Evaluation evaluationIfNoMatch, RelationshipType type, RelationshipType... orAnyOfTheseTypes) Returns an Evaluator which compares the type of the last relationship in a Path to a given set of relationship types (one or more).If the type of the last relationship in a path is of one of the given types then evaluationIfMatch will be returned, otherwise evaluationIfNoMatch will be returned.
static <STATE> PathEvaluator<STATE>	pruneWhereEndNodeIs(Node... nodes)
static <STATE> PathEvaluator<STATE>	pruneWhereLastRelationshipTypeIs(RelationshipType type, RelationshipType... orAnyOfTheseTypes)
static <STATE> PathEvaluator<STATE>	toDepth(int depth) Returns an Evaluator which includes positions down to depth and prunes everything deeper than that.

Methods inherited from class java.lang.Object

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

Constructor Detail

Evaluators

public Evaluators()

Method Detail

all

public static <STATE> PathEvaluator<STATE> all()

Type Parameters:

STATE - the type of the state object.

Returns:

an evaluator which includes everything it encounters and doesn't prune anything.

excludeStartPosition

public static PathEvaluator excludeStartPosition()

Returns:

an evaluator which never prunes and includes everything except the first position, i.e. the the start node.

toDepth

public static <STATE> PathEvaluator<STATE> toDepth(int depth)

Returns an Evaluator which includes positions down to depth and prunes everything deeper than that.

Type Parameters:

STATE - the type of the state object.

Parameters:

depth - the max depth to traverse to.

Returns:

Returns an Evaluator which includes positions down to depth and prunes everything deeper than that.

fromDepth

public static <STATE> PathEvaluator<STATE> fromDepth(int depth)

Returns an Evaluator which only includes positions from depth and deeper and never prunes anything.

Type Parameters:

STATE - the type of the state object.

Parameters:

depth - the depth to start include positions from.

Returns:

Returns an Evaluator which only includes positions from depth and deeper and never prunes anything.

atDepth

public static <STATE> PathEvaluator<STATE> atDepth(int depth)

Returns an Evaluator which only includes positions at depth and prunes everything deeper than that.

Type Parameters:

STATE - the type of the state object.

Parameters:

depth - the depth to start include positions from.

Returns:

Returns an Evaluator which only includes positions at depth and prunes everything deeper than that.

includingDepths

public static <STATE> PathEvaluator<STATE> includingDepths(int minDepth,
                                                           int maxDepth)

Returns an Evaluator which only includes positions between depths minDepth and maxDepth. It prunes everything deeper than maxDepth.

Type Parameters:

STATE - the type of the state object.

Parameters:

minDepth - minimum depth a position must have to be included.

maxDepth - maximum depth a position must have to be included.

Returns:

Returns an Evaluator which only includes positions between depths minDepth and maxDepth. It prunes everything deeper than maxDepth.

lastRelationshipTypeIs

public static <STATE> PathEvaluator<STATE> lastRelationshipTypeIs(Evaluation evaluationIfMatch,
                                                                  Evaluation evaluationIfNoMatch,
                                                                  RelationshipType type,
                                                                  RelationshipType... orAnyOfTheseTypes)

Returns an Evaluator which compares the type of the last relationship in a Path to a given set of relationship types (one or more).If the type of the last relationship in a path is of one of the given types then evaluationIfMatch will be returned, otherwise evaluationIfNoMatch will be returned.

Type Parameters:

STATE - the type of the state object.

Parameters:

evaluationIfMatch - the Evaluation to return if the type of the last relationship in the path matches any of the given types.

evaluationIfNoMatch - the Evaluation to return if the type of the last relationship in the path doesn't match any of the given types.

type - the (first) type (of possibly many) to match the last relationship in paths with.

orAnyOfTheseTypes - additional types to match the last relationship in paths with.

Returns:

an Evaluator which compares the type of the last relationship in a Path to a given set of relationship types.

includeWhereLastRelationshipTypeIs

public static <STATE> PathEvaluator<STATE> includeWhereLastRelationshipTypeIs(RelationshipType type,
                                                                              RelationshipType... orAnyOfTheseTypes)

Type Parameters:

STATE - the type of the state object.

Parameters:

type - the (first) type (of possibly many) to match the last relationship in paths with.

orAnyOfTheseTypes - types to match the last relationship in paths with. If any matches it's considered a match.

Returns:

an Evaluator which compares the type of the last relationship in a Path to a given set of relationship types.

See Also:

Uses {@link Evaluation#INCLUDE_AND_CONTINUE} for {@code evaluationIfMatch} and {@link Evaluation#EXCLUDE_AND_CONTINUE} for {@code evaluationIfNoMatch}.

pruneWhereLastRelationshipTypeIs

public static <STATE> PathEvaluator<STATE> pruneWhereLastRelationshipTypeIs(RelationshipType type,
                                                                            RelationshipType... orAnyOfTheseTypes)

Type Parameters:

STATE - the type of the state object.

Parameters:

type - the (first) type (of possibly many) to match the last relationship in paths with.

orAnyOfTheseTypes - types to match the last relationship in paths with. If any matches it's considered a match.

Returns:

an Evaluator which compares the type of the last relationship in a Path to a given set of relationship types.

See Also:

Uses {@link Evaluation#INCLUDE_AND_PRUNE} for {@code evaluationIfMatch} and {@link Evaluation#INCLUDE_AND_CONTINUE} for {@code evaluationIfNoMatch}.

endNodeIs

public static <STATE> PathEvaluator<STATE> endNodeIs(Evaluation evaluationIfMatch,
                                                     Evaluation evaluationIfNoMatch,
                                                     Node... possibleEndNodes)

An Evaluator which will return evaluationIfMatch if Path.endNode() for a given path is any of nodes, else evaluationIfNoMatch.

Type Parameters:

STATE - the type of the state object.

Parameters:

evaluationIfMatch - the Evaluation to return if the Path.endNode() is any of the nodes in nodes.

evaluationIfNoMatch - the Evaluation to return if the Path.endNode() doesn't match any of the nodes in nodes.

possibleEndNodes - a set of nodes to match to end nodes in paths.

Returns:

an Evaluator which will return evaluationIfMatch if Path.endNode() for a given path is any of nodes, else evaluationIfNoMatch.

includeWhereEndNodeIs

public static <STATE> PathEvaluator<STATE> includeWhereEndNodeIs(Node... nodes)

Include paths with the specified end nodes. Uses Evaluators#endNodeIs(Evaluation, Evaluation, Node...) with Evaluation.INCLUDE_AND_CONTINUE for evaluationIfMatch and Evaluation.EXCLUDE_AND_CONTINUE for evaluationIfNoMatch.

Type Parameters:

STATE - the type of the state object.

Parameters:

nodes - end nodes for paths to be included in the result.

Returns:

paths where the end node is one of nodes

pruneWhereEndNodeIs

public static <STATE> PathEvaluator<STATE> pruneWhereEndNodeIs(Node... nodes)

includeIfContainsAll

public static <STATE> PathEvaluator<STATE> includeIfContainsAll(Node... nodes)

Evaluator which decides to include a Path if all the nodes exist in it.

Type Parameters:

STATE - the type of the state object.

Parameters:

nodes - Nodes that must exist in a Path for it to be included.

Returns:

Evaluation.INCLUDE_AND_CONTINUE if all nodes exist in a given Path, otherwise Evaluation.EXCLUDE_AND_CONTINUE.

includeIfAcceptedByAny

public static <STATE> PathEvaluator<STATE> includeIfAcceptedByAny(PathEvaluator... evaluators)

Whereas adding Evaluators to a TraversalDescription puts those evaluators in AND-mode this can group many evaluators in OR-mode.

Type Parameters:

STATE - the type of the state object.

Parameters:

evaluators - represented as one evaluators. If any of the evaluators decides to include a path it will be included.

Returns:

an Evaluator which decides to include a path if any of the supplied evaluators wants to include it.

includeIfAcceptedByAny

public static <STATE> PathEvaluator<STATE> includeIfAcceptedByAny(Evaluator... evaluators)

Whereas adding Evaluators to a TraversalDescription puts those evaluators in AND-mode this can group many evaluators in OR-mode.

Type Parameters:

STATE - the type of the state object.

Parameters:

evaluators - represented as one evaluators. If any of the evaluators decides to include a path it will be included.

Returns:

an Evaluator which decides to include a path if any of the supplied evaluators wants to include it.

endNodeIsAtDepth

public static <STATE> PathEvaluator<STATE> endNodeIsAtDepth(int depth,
                                                            Node... possibleEndNodes)

Returns Evaluators for paths with the specified depth and with an end node from the list of possibleEndNodes.

Type Parameters:

STATE - the type of the state object.

Parameters:

depth - The exact depth to filter the returned path evaluators.

possibleEndNodes - Filter for the possible nodes to end the path on.

Returns:

Evaluators for paths with the specified depth and with an end node from the list of possibleEndNodes.