Package org.apache.tinkerpop.gremlin.gql

Class QueryEdge

java.lang.Object

org.apache.tinkerpop.gremlin.gql.QueryEdge

public final class QueryEdge
extends Object

Represents an edge pattern element in a GQL MATCH clause. An edge connects a source QueryVertex to a target QueryVertex with an optional variable name, optional label constraint, a traversal direction, and optional property predicates on the edge itself.

Direction semantics follow the GQL arrow notation:

• -[:L]-> is Direction.OUT — edge goes from source to target
• <-[:L]- is Direction.IN — edge goes from target to source
• -[:L]- is Direction.BOTH — undirected, either direction matches

Constructor Summary

Constructors

Constructor	Description
QueryEdge(String variable, String label, Direction direction, QueryVertex source, QueryVertex target)
QueryEdge(String variable, String label, Direction direction, QueryVertex source, QueryVertex target, List<PropertyPredicate> predicates)

Method Summary

Modifier and Type	Method	Description
Direction	getDirection()	Returns the traversal direction: Direction.OUT, Direction.IN, or Direction.BOTH.
String	getLabel()	Returns the label constraint for this edge, or null if unconstrained.
List<PropertyPredicate>	getPredicates()	Returns the property equality predicates on this edge, or an empty list if none were specified.
QueryVertex	getSource()	Returns the source (left-hand) vertex of this edge pattern.
QueryVertex	getTarget()	Returns the target (right-hand) vertex of this edge pattern.
String	getVariable()	Returns the variable name bound to this edge, or null if anonymous.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

QueryEdge

public QueryEdge(String variable,
 String label,
 Direction direction,
 QueryVertex source,
 QueryVertex target,
 List<PropertyPredicate> predicates)

QueryEdge

public QueryEdge(String variable,
 String label,
 Direction direction,
 QueryVertex source,
 QueryVertex target)

Method Details

getVariable

public String getVariable()

Returns the variable name bound to this edge, or null if anonymous.

getLabel

public String getLabel()

Returns the label constraint for this edge, or null if unconstrained.

getDirection

public Direction getDirection()

Returns the traversal direction: Direction.OUT, Direction.IN, or Direction.BOTH.

getSource

public QueryVertex getSource()

Returns the source (left-hand) vertex of this edge pattern.

getTarget

public QueryVertex getTarget()

Returns the target (right-hand) vertex of this edge pattern.

getPredicates

public List<PropertyPredicate> getPredicates()

Returns the property equality predicates on this edge, or an empty list if none were specified.

toString

public String toString()

Overrides:

toString in class Object