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

Class SelectOneStep<S,E>

java.lang.Object

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

org.apache.tinkerpop.gremlin.process.traversal.step.map.MapStep<S,E>

org.apache.tinkerpop.gremlin.process.traversal.step.map.SelectOneStep<S,E>

All Implemented Interfaces:

Serializable, Cloneable, Iterator<Traverser<E>>, Step<S,E>, PathProcessor, Scoping, TraversalParent

public final class SelectOneStep<S,E>
extends MapStep<S,E>
implements TraversalParent, Scoping, PathProcessor

Author:

Marko A. Rodriguez (http://markorodriguez.com)

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.Scoping

Scoping.Variable

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.process.traversal.step.PathProcessor

PathProcessor.ElementRequirement

Field Summary

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

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

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

TYPICAL_GLOBAL_REQUIREMENTS, TYPICAL_GLOBAL_REQUIREMENTS_ARRAY, TYPICAL_LOCAL_REQUIREMENTS, TYPICAL_LOCAL_REQUIREMENTS_ARRAY

Constructor Summary

Constructors

Constructor and Description
SelectOneStep(Traversal.Admin traversal, Pop pop, String selectKey)

Method Summary

Modifier and Type	Method and Description
void	addLocalChild(Traversal.Admin<?,?> selectTraversal)
SelectOneStep<S,E>	clone() Cloning is used to duplicate steps for the purpose of traversal optimization and OLTP replication.
List<Traversal.Admin<S,E>>	getLocalChildren()
Set<TraverserRequirement>	getRequirements() Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly.
Set<String>	getScopeKeys()
int	hashCode()
protected E	map(Traverser.Admin<S> traverser)
String	toString()

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

processNextStart

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

addLabel, addStart, addStarts, equals, getId, getLabels, getNextStep, getPreviousStep, getTraversal, hasNext, next, removeLabel, reset, 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.TraversalParent

addGlobalChild, asStep, getGlobalChildren, getSelfAndChildRequirements, integrateChild, removeGlobalChild, removeLocalChild

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

getNullableScopeValue, getScopeValue

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

getMaxRequirement

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

equals

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Constructor Detail

SelectOneStep

public SelectOneStep(Traversal.Admin traversal,
                     Pop pop,
                     String selectKey)

Method Detail

map

protected E map(Traverser.Admin<S> traverser)

Specified by:

map in class MapStep<S,E>

toString

public String toString()

Overrides:

toString in class AbstractStep<S,E>

clone

public SelectOneStep<S,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 reset() is called. Moreover, the previous and next steps should be set to EmptyStep.

Specified by:

clone in interface Step<S,E>

Overrides:

clone in class AbstractStep<S,E>

Returns:

The cloned step

hashCode

public int hashCode()

Overrides:

hashCode in class AbstractStep<S,E>

getLocalChildren

public List<Traversal.Admin<S,E>> getLocalChildren()

Specified by:

getLocalChildren in interface TraversalParent

addLocalChild

public void addLocalChild(Traversal.Admin<?,?> selectTraversal)

Specified by:

addLocalChild in interface TraversalParent

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<S,E>

Returns:

the set of requirements

getScopeKeys

public Set<String> getScopeKeys()

Specified by:

getScopeKeys in interface Scoping