org.apache.tinkerpop.gremlin.process.traversal

Interface Path

All Superinterfaces:

Cloneable, Iterable<Object>

public interface Path
extends Cloneable, Iterable<Object>

A Path denotes a particular walk through a Graph as defined by a Traversal. In abstraction, any Path implementation maintains two lists: a list of sets of labels and a list of objects. The list of labels are the labels of the steps traversed. The list of objects are the objects traversed.

Author:

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

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Path.Exceptions

Method Summary

Modifier and Type	Method and Description
Path	clone()
Path	extend(Object object, Set<String> labels) Add a new step to the path with an object and any number of associated labels.
Path	extend(Set<String> labels) Add labels to the head of the path.
default void	forEach(BiConsumer<Object,Set<String>> consumer)
default <A> A	get(int index) Get the object associated with the specified index into the path.
default <A> A	get(Pop pop, String label) Pop the object(s) associated with the label of the path.
default <A> A	get(String label) Get the object associated with the particular label of the path.
default boolean	hasLabel(String label) Return true if the path has the specified label, else return false.
default <A> A	head() Get the head of the path.
default boolean	isEmpty() Determine if the path is empty or not.
default boolean	isSimple() Determines whether the path is a simple or not.
default Iterator<Object>	iterator()
List<Set<String>>	labels() An ordered list of the labels associated with the path The set of labels for a particular step are ordered by the order in which extend(Object, Set) was called.
List<Object>	objects() An ordered list of the objects in the path.
default boolean	popEquals(Pop pop, Object other)
Path	retract(Set<String> labels) Remove labels from path.
default int	size() Get the number of step in the path.
default Stream<org.javatuples.Pair<Object,Set<String>>>	stream()
default Path	subPath(String fromLabel, String toLabel) Isolate a sub-path from the path object.

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Method Detail

size

default int size()

Get the number of step in the path.

Returns:

the size of the path

isEmpty

default boolean isEmpty()

Determine if the path is empty or not.

Returns:

whether the path is empty or not.

head

default <A> A head()

Get the head of the path.

Type Parameters:

A - the type of the head of the path

Returns:

the head of the path

extend

Path extend(Object object,
            Set<String> labels)

Add a new step to the path with an object and any number of associated labels.

Parameters:

object - the new head of the path

labels - the labels at the head of the path

Returns:

the extended path

extend

Path extend(Set<String> labels)

Add labels to the head of the path.

Parameters:

labels - the labels at the head of the path

Returns:

the path with added labels

retract

Path retract(Set<String> labels)

Remove labels from path.

Parameters:

labels - the labels to remove

Returns:

the path with removed labels

get

default <A> A get(String label)
           throws IllegalArgumentException

Get the object associated with the particular label of the path. If the path as multiple labels of the type, then return a List of those objects.

Type Parameters:

A - the type of the object associated with the label

Parameters:

label - the label of the path

Returns:

the object associated with the label of the path

Throws:

IllegalArgumentException - if the path does not contain the label

get

default <A> A get(Pop pop,
                  String label)
           throws IllegalArgumentException

Pop the object(s) associated with the label of the path.

Type Parameters:

A - the type of the object associated with the label

Parameters:

pop - first for least recent, last for most recent, and all for all in a list

label - the label of the path

Returns:

the object associated with the label of the path

Throws:

IllegalArgumentException - if the path does not contain the label

get

default <A> A get(int index)

Get the object associated with the specified index into the path.

Type Parameters:

A - the type of the object associated with the index

Parameters:

index - the index of the path

Returns:

the object associated with the index of the path

hasLabel

default boolean hasLabel(String label)

Return true if the path has the specified label, else return false.

Parameters:

label - the label to search for

Returns:

true if the label exists in the path

objects

List<Object> objects()

An ordered list of the objects in the path.

Returns:

the objects of the path

labels

List<Set<String>> labels()

An ordered list of the labels associated with the path The set of labels for a particular step are ordered by the order in which extend(Object, Set) was called.

Returns:

the labels of the path

clone

Path clone()

isSimple

default boolean isSimple()

Determines whether the path is a simple or not. A simple path has no cycles and thus, no repeated objects.

Returns:

Whether the path is simple or not

iterator

default Iterator<Object> iterator()

Specified by:

iterator in interface Iterable<Object>

forEach

default void forEach(BiConsumer<Object,Set<String>> consumer)

stream

default Stream<org.javatuples.Pair<Object,Set<String>>> stream()

popEquals

default boolean popEquals(Pop pop,
                          Object other)

subPath

default Path subPath(String fromLabel,
                     String toLabel)

Isolate a sub-path from the path object. The isolation is based solely on the path labels. The to-label is inclusive. Thus, from "b" to "c" would isolate the example path as follows a,[b,c],d. Note that if there are multiple path segments with the same label, then its the last occurrence that is isolated. For instance, from "b" to "c" would be a,b,[b,c,d,c].

Parameters:

fromLabel - The label to start recording the sub-path from.

toLabel - The label to end recording the sub-path to.

Returns:

the isolated sub-path.