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

Interface TraversalStrategies

All Superinterfaces:

Cloneable, Iterable<TraversalStrategy<?>>, Serializable

All Known Implementing Classes:

DefaultTraversalStrategies, EmptyTraversalStrategies

public interface TraversalStrategies
extends Serializable, Cloneable, Iterable<TraversalStrategy<?>>

A Traversal maintains a set of TraversalStrategy instances within a TraversalStrategies object. TraversalStrategies are responsible for compiling a traversal prior to its execution.

Author:

Marko A. Rodriguez (http://markorodriguez.com), Matthias Broecheler (me@matthiasb.com)

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	TraversalStrategies.GlobalCache

Field Summary

Fields

Modifier and Type	Field	Description
static List<Class<? extends TraversalStrategy>>	STRATEGY_CATEGORIES

Method Summary

Modifier and Type	Method	Description
TraversalStrategies	addStrategies(TraversalStrategy<?>... strategies)	Add all the provided TraversalStrategy instances to the current collection.
TraversalStrategies	clone()
default <T extends TraversalStrategy> Optional<T>	getStrategy(Class<T> traversalStrategyClass)	Return the TraversalStrategy instance associated with the provided class.
Iterator<TraversalStrategy<?>>	iterator()	Return an Iterator of the TraversalStrategy instances.
TraversalStrategies	removeStrategies(Class<? extends TraversalStrategy>... strategyClasses)	Remove all the provided TraversalStrategy classes from the current collection.
static Set<TraversalStrategy<?>>	sortStrategies(Set<TraversalStrategy<?>> strategies)	Sorts the list of provided strategies such that the TraversalStrategy.applyPost() and TraversalStrategy.applyPrior() dependencies are respected.
default List<TraversalStrategy<?>>	toList()	Return an immutable list of the TraversalStrategy instances.
static void	visit(Map<Class<? extends TraversalStrategy>,Set<Class<? extends TraversalStrategy>>> dependencyMap, List<Class<? extends TraversalStrategy>> sortedStrategyClasses, Set<Class<? extends TraversalStrategy>> seenStrategyClases, List<Class<? extends TraversalStrategy>> unprocessedStrategyClasses, Class<? extends TraversalStrategy> strategyClass)

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

STRATEGY_CATEGORIES

static final List<Class<? extends TraversalStrategy>> STRATEGY_CATEGORIES

Method Detail

toList

default List<TraversalStrategy<?>> toList()

Return an immutable list of the TraversalStrategy instances.

iterator

Iterator<TraversalStrategy<?>> iterator()

Return an Iterator of the TraversalStrategy instances.

Specified by:

iterator in interface Iterable<TraversalStrategy<?>>

getStrategy

default <T extends TraversalStrategy> Optional<T> getStrategy(Class<T> traversalStrategyClass)

Return the TraversalStrategy instance associated with the provided class.

Type Parameters:

T - the strategy class type

Parameters:

traversalStrategyClass - the class of the strategy to get

Returns:

an optional containing the strategy instance or not

addStrategies

TraversalStrategies addStrategies(TraversalStrategy<?>... strategies)

Add all the provided TraversalStrategy instances to the current collection. When all the provided strategies have been added, the collection is resorted. If a strategy class is found to already be defined, it is removed and replaced by the newly added one.

Parameters:

strategies - the traversal strategies to add

Returns:

the newly updated/sorted traversal strategies collection

removeStrategies

TraversalStrategies removeStrategies(Class<? extends TraversalStrategy>... strategyClasses)

Remove all the provided TraversalStrategy classes from the current collection. When all the provided strategies have been removed, the collection is resorted.

Parameters:

strategyClasses - the traversal strategies to remove by their class

Returns:

the newly updated/sorted traversal strategies collection

clone

TraversalStrategies clone()

sortStrategies

static Set<TraversalStrategy<?>> sortStrategies(Set<TraversalStrategy<?>> strategies)

Sorts the list of provided strategies such that the TraversalStrategy.applyPost() and TraversalStrategy.applyPrior() dependencies are respected.

Note, that the order may not be unique.

Parameters:

strategies - the traversal strategies to sort

visit

static void visit(Map<Class<? extends TraversalStrategy>,Set<Class<? extends TraversalStrategy>>> dependencyMap,
                  List<Class<? extends TraversalStrategy>> sortedStrategyClasses,
                  Set<Class<? extends TraversalStrategy>> seenStrategyClases,
                  List<Class<? extends TraversalStrategy>> unprocessedStrategyClasses,
                  Class<? extends TraversalStrategy> strategyClass)