Package org.apache.tinkerpop.gremlin.process.traversal.traverser

Interface NL_SL_Traverser<T>

All Superinterfaces:

Attachable<T>, Cloneable, Comparable<Traverser<T>>, Serializable, Traverser<T>, Traverser.Admin<T>

All Known Implementing Classes:

B_LP_NL_O_P_S_SE_SL_Traverser, B_LP_NL_O_S_SE_SL_Traverser, B_LP_O_P_S_SE_SL_Traverser, B_LP_O_S_SE_SL_Traverser, B_NL_O_S_SE_SL_Traverser, B_O_S_SE_SL_Traverser, LP_NL_O_OB_P_S_SE_SL_Traverser, LP_NL_O_OB_S_SE_SL_Traverser, LP_O_OB_P_S_SE_SL_Traverser, LP_O_OB_S_SE_SL_Traverser, NL_O_OB_S_SE_SL_Traverser, O_OB_S_SE_SL_Traverser

public interface NL_SL_Traverser<T>
extends Traverser.Admin<T>

Intermediate helper interface for Traversers that support loops. Implementations are expected to override either the single or nested loop functions depending on the type of loop TraverserRequirement they are using.

Note: it would be nice to separate the TraverserRequirement.SINGLE_LOOP vs TraverserRequirement.NESTED_LOOP logic into different traverser interfaces in the future however the current Traverser class hierarchy makes that difficult as Traversers that support nested loops extend from Traversers that support single loops but override all single loop logic with nested loop logic.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.tinkerpop.gremlin.structure.util.Attachable

Attachable.Exceptions, Attachable.Method

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

Traverser.Admin<T>

Field Summary

Fields inherited from interface org.apache.tinkerpop.gremlin.structure.util.Attachable

logger

Fields inherited from interface org.apache.tinkerpop.gremlin.process.traversal.Traverser.Admin

HALT

Method Summary

Modifier and Type	Method	Description
default void	copyNestedLoops(Stack<LabelledCounter> targetNestedLoops, org.apache.commons.collections.map.ReferenceMap targetLoopNames)
default Set<String>	getLoopNames()	If this traverser supports loops then return the loop names if any.
TraverserRequirement	getLoopRequirement()
default int	getNestedLoopCount(String loopName)
default org.apache.commons.collections.map.ReferenceMap	getNestedLoopNames()	Override this method to support nested loops.
default Stack<LabelledCounter>	getNestedLoops()	Override this method to support nested loops.
default short	getSingleLoopCount()	Override this method to support single loop.
default String	getSingleLoopName()	Override this method to support single loop.
default String	getSingleLoopStepLabel()	Override this method to support single loop.
default TraverserRequirement	getValidLoopRequirement()
default void	incrLoops()	Increment the number of times the traverser has gone through a looping section of traversal.
default void	initialiseLoops(String stepLabel, String loopName)	Initialises loops depending on the getLoopRequirement() loop type.
default void	initialiseNestedLoops(String stepLabel, String loopName)
default int	loops()	Return the number of times the traverser has gone through a looping section of a traversal.
default int	loops(String loopName)	Obtain a loop count for a named loop or for the current loop count for single loops or the latest loop count for nested loops.
default void	resetLoops()	Resets loops depending on the getLoopRequirement() loop type.
default void	setSingleLoopCount(short loops)	Override this method to support single loop.
default void	setSingleLoopName(String loopName)	Override this method to support single loop.
default void	setSingleLoopStepLabel(String stepLabel)	Override this method to support single loop.

Methods inherited from interface org.apache.tinkerpop.gremlin.structure.util.Attachable

get

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

asAdmin, bulk, clone, compareTo, get, path, path, path, sack, sack, sideEffects, sideEffects

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.Traverser.Admin

addLabels, attach, detach, dropLabels, dropPath, getSideEffects, getStepId, getTags, isHalted, keepLabels, merge, set, setBulk, setSideEffects, setStepId, split, split

Method Detail

getLoopRequirement

TraverserRequirement getLoopRequirement()

Returns:

the supported loop type - either TraverserRequirement.NESTED_LOOP or TraverserRequirement.SINGLE_LOOP

getNestedLoops

default Stack<LabelledCounter> getNestedLoops()

Override this method to support nested loops.

Returns:

the Stack of LabelledCounter which holds the nested loops.

getNestedLoopNames

default org.apache.commons.collections.map.ReferenceMap getNestedLoopNames()

Override this method to support nested loops.

Returns:

the ReferenceMap where key=loop name and value=reference to the LabelledCounter.

getSingleLoopCount

default short getSingleLoopCount()

Override this method to support single loop.

Returns:

the single loop count.

setSingleLoopCount

default void setSingleLoopCount(short loops)

Override this method to support single loop. Sets the single loop count.

getSingleLoopName

default String getSingleLoopName()

Override this method to support single loop.

Returns:

the single loop name.

setSingleLoopName

default void setSingleLoopName(String loopName)

Override this method to support single loop. Sets the single loop name.

getSingleLoopStepLabel

default String getSingleLoopStepLabel()

Override this method to support single loop.

Returns:

the single loop step label.

setSingleLoopStepLabel

default void setSingleLoopStepLabel(String stepLabel)

Override this method to support single loop. Sets the single loop step label.

incrLoops

default void incrLoops()

Description copied from interface: Traverser.Admin

Increment the number of times the traverser has gone through a looping section of traversal.

Specified by:

incrLoops in interface Traverser.Admin<T>

loops

default int loops()

Description copied from interface: Traverser

Return the number of times the traverser has gone through a looping section of a traversal.

Specified by:

loops in interface Traverser<T>

Returns:

the current loop count for single loops or the latest loop count for nested loops.

loops

default int loops(String loopName)

Obtain a loop count for a named loop or for the current loop count for single loops or the latest loop count for nested loops.

Specified by:

loops in interface Traverser<T>

Parameters:

loopName - the optional name applied to the loop

Returns:

the count for the loop identified by the given loopName or current loop count for single loops or latest loop for nested loops.

initialiseLoops

default void initialiseLoops(String stepLabel,
                             String loopName)

Initialises loops depending on the getLoopRequirement() loop type.

Specified by:

initialiseLoops in interface Traverser.Admin<T>

Parameters:

stepLabel - the label of the step initialising the loops.

loopName - the optional user defined name for referencing the loop counter

resetLoops

default void resetLoops()

Resets loops depending on the getLoopRequirement() loop type.

Specified by:

resetLoops in interface Traverser.Admin<T>

getLoopNames

default Set<String> getLoopNames()

Description copied from interface: Traverser.Admin

If this traverser supports loops then return the loop names if any.

Specified by:

getLoopNames in interface Traverser.Admin<T>

Returns:

the loop names that can be used to reference loops.

getValidLoopRequirement

default TraverserRequirement getValidLoopRequirement()

initialiseNestedLoops

default void initialiseNestedLoops(String stepLabel,
                                   String loopName)

getNestedLoopCount

default int getNestedLoopCount(String loopName)

copyNestedLoops

default void copyNestedLoops(Stack<LabelledCounter> targetNestedLoops,
                             org.apache.commons.collections.map.ReferenceMap targetLoopNames)