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

Class FoldStep<S,E>

java.lang.Object

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

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

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

All Implemented Interfaces:

Serializable, Cloneable, Iterator<Traverser.Admin<E>>, Step<S,E>, Barrier<E>, Generating<E,E>, MemoryComputing<E>

public final class FoldStep<S,E>
extends ReducingBarrierStep<S,E>

Author:

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

See Also:

• Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	FoldStep.FoldBiOperator<E>

Nested classes/interfaces inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.ReducingBarrierStep

ReducingBarrierStep.NonEmittingSeed

Field Summary

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

hasProcessedOnce, NON_EMITTING_SEED, reducingBiOperator, seedSupplier

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

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

Constructor Summary

Constructors

Constructor	Description
FoldStep(Traversal.Admin traversal)
FoldStep(Traversal.Admin traversal, Supplier<E> seed, BiFunction<E,S,E> foldFunction)

Method Summary

Modifier and Type	Method	Description
Set<TraverserRequirement>	getRequirements()	Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly.
boolean	isListFold()
E	projectTraverser(Traverser.Admin<S> traverser)

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

addBarrier, clone, done, generateSeedFromStarts, getBiOperator, getEmptyBarrier, getMemoryComputeKey, getSeedSupplier, hasNextBarrier, nextBarrier, processAllStarts, processNextStart, reset, setReducingBiOperator, setSeedSupplier

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

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

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.Generating

generateFinalResult

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

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

equals

Constructor Details

FoldStep

public FoldStep(Traversal.Admin traversal)

FoldStep

public FoldStep(Traversal.Admin traversal,
 Supplier<E> seed,
 BiFunction<E,S,E> foldFunction)

Method Details

projectTraverser

public E projectTraverser(Traverser.Admin<S> traverser)

Specified by:

projectTraverser in class ReducingBarrierStep<S,E>

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.

Returns:

the set of requirements

isListFold

public boolean isListFold()