Package org.apache.tinkerpop.gremlin.process.traversal.step.map

Class VertexStepPlaceholder<E extends Element>

java.lang.Object

org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep<S,E>

org.apache.tinkerpop.gremlin.process.traversal.step.map.FlatMapStep<Vertex,E>

org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStepPlaceholder<E>

All Implemented Interfaces:

Serializable, AutoCloseable, Cloneable, Iterator<Traverser.Admin<E>>, Step<Vertex,E>, GValueHolder<Vertex,E>, VertexStepContract<E>

public class VertexStepPlaceholder<E extends Element>
extends FlatMapStep<Vertex,E>
implements GValueHolder<Vertex,E>, VertexStepContract<E>

Handles the logic of traversing to adjacent vertices or edges given a direction and edge labels for steps like, out, in, both, outE, inE, and bothE.

See Also:

Serialized Form

Field Summary

Fields inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

id, labels, nextEnd, nextStep, previousStep, starts, traversal, traverserStepIdAndLabelsSetByChild

Fields inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.map.VertexStepContract

CONCRETE_STEPS

Constructor Summary

Constructors

Constructor	Description
VertexStepPlaceholder(Traversal.Admin traversal, Class<E> returnClass, Direction direction, GValue<String>... edgeLabels)

Method Summary

Modifier and Type	Method	Description
VertexStep<E>	asConcreteStep()
VertexStepPlaceholder<E>	clone()	Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication.
void	close()
protected Iterator<E>	flatMap(Traverser.Admin<Vertex> traverser)
Direction	getDirection()
String[]	getEdgeLabels()
GValue<String>[]	getEdgeLabelsAsGValues()
Collection<GValue<?>>	getGValues()
Set<TraverserRequirement>	getRequirements()	Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly.
Class<E>	getReturnClass()
int	hashCode()
boolean	isParameterized()
boolean	returnsEdge()	Determines if the step returns edges.
boolean	returnsVertex()	Determines if the step returns vertices.
void	reverseDirection()
String	toString()
void	updateVariable(String name, Object value)

Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.map.FlatMapStep

closeIterator, processNextStart, reset

Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

addLabel, addStart, addStarts, clearLabels, equals, getId, getLabels, getNextStep, getPreviousStep, getStarts, getTraversal, hasNext, hasStarts, isTraverserStepIdAndLabelsSetByChild, next, prepareTraversalForNextStep, removeLabel, setId, setNextStep, setPreviousStep, setTraversal

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.GValueHolder

reduce

Methods inherited from interface java.util.Iterator

forEachRemaining, hasNext, next, remove

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.Step

addLabel, addStart, addStarts, clearLabels, equals, getId, getLabels, getNextStep, getPreviousStep, getTraversal, hasStarts, removeLabel, reset, setId, setNextStep, setPreviousStep, setTraversal

Constructor Detail

VertexStepPlaceholder

public VertexStepPlaceholder(Traversal.Admin traversal,
                             Class<E> returnClass,
                             Direction direction,
                             GValue<String>... edgeLabels)

Method Detail

getDirection

public Direction getDirection()

Specified by:

getDirection in interface VertexStepContract<E extends Element>

getEdgeLabels

public String[] getEdgeLabels()

Specified by:

getEdgeLabels in interface VertexStepContract<E extends Element>

getEdgeLabelsAsGValues

public GValue<String>[] getEdgeLabelsAsGValues()

Specified by:

getEdgeLabelsAsGValues in interface VertexStepContract<E extends Element>

getReturnClass

public Class<E> getReturnClass()

Specified by:

getReturnClass in interface VertexStepContract<E extends Element>

reverseDirection

public void reverseDirection()

Specified by:

reverseDirection in interface VertexStepContract<E extends Element>

returnsVertex

public boolean returnsVertex()

Determines if the step returns vertices.

Specified by:

returnsVertex in interface VertexStepContract<E extends Element>

returnsEdge

public boolean returnsEdge()

Determines if the step returns edges.

Specified by:

returnsEdge in interface VertexStepContract<E extends Element>

flatMap

protected Iterator<E> flatMap(Traverser.Admin<Vertex> traverser)

Specified by:

flatMap in class FlatMapStep<Vertex,E extends Element>

toString

public String toString()

Overrides:

toString in class AbstractStep<Vertex,E extends Element>

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractStep<Vertex,E extends Element>

clone

public VertexStepPlaceholder<E> clone()

Description copied from interface: Step

Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication. When cloning a step, it is important that the steps, the cloned step is equivalent to the state of the step when Step.reset() is called. Moreover, the previous and next steps should be set to EmptyStep.

Specified by:

clone in interface Step<Vertex,E extends Element>

Overrides:

clone in class AbstractStep<Vertex,E extends Element>

Returns:

The cloned step

getRequirements

public Set<TraverserRequirement> getRequirements()

Description copied from interface: Step

Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly. The provided default implements returns an empty set.

Specified by:

getRequirements in interface Step<Vertex,E extends Element>

Specified by:

getRequirements in interface VertexStepContract<E extends Element>

Returns:

the set of requirements

asConcreteStep

public VertexStep<E> asConcreteStep()

Specified by:

asConcreteStep in interface GValueHolder<Vertex,E extends Element>

isParameterized

public boolean isParameterized()

Specified by:

isParameterized in interface GValueHolder<Vertex,E extends Element>

updateVariable

public void updateVariable(String name,
                           Object value)

Specified by:

updateVariable in interface GValueHolder<Vertex,E extends Element>

getGValues

public Collection<GValue<?>> getGValues()

Specified by:

getGValues in interface GValueHolder<Vertex,E extends Element>

close

public void close()
           throws Exception

Specified by:

close in interface AutoCloseable

Throws:

Exception