org.janusgraph.graphdb.query

Interface JanusGraphPredicate

All Superinterfaces:

BiPredicate<Object,Object>

All Known Implementing Classes:

AndJanusPredicate, Cmp, ConnectiveJanusPredicate, Contain, Geo, OrJanusPredicate, Text

public interface JanusGraphPredicate
extends BiPredicate<Object,Object>

A special kind of BiPredicate which marks all the predicates that are natively supported by JanusGraph and known to the query optimizer. Contains some custom methods that JanusGraph needs for query answering and evaluation.

This class contains a subclass used to convert Tinkerpop's BiPredicate implementations to the corresponding JanusGraph predicates.

Author:

Matthias Broecheler ([email protected])

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	JanusGraphPredicate.Converter

Method Summary

Modifier and Type	Method and Description
boolean	hasNegation() Whether this predicate has a predicate that is semantically its negation.
boolean	isQNF() Returns true if this predicate is in query normal form.
boolean	isValidCondition(Object condition) Whether the given condition is a valid condition for this predicate.
boolean	isValidValueType(Class<?> clazz) Whether the given class is a valid data type for a value to which this predicate may be applied.
JanusGraphPredicate	negate() Returns the negation of this predicate if it exists, otherwise an exception is thrown.
boolean	test(Object value, Object condition)

Methods inherited from interface java.util.function.BiPredicate

and, or

Method Detail

isValidCondition

boolean isValidCondition(Object condition)

Whether the given condition is a valid condition for this predicate.

For instance, the Cmp.GREATER_THAN would require that the condition is comparable and not null.

Parameters:

condition -

Returns:

isValidValueType

boolean isValidValueType(Class<?> clazz)

Whether the given class is a valid data type for a value to which this predicate may be applied.

For instance, the Cmp.GREATER_THAN can only be applied to Comparable values.

Parameters:

clazz -

Returns:

hasNegation

boolean hasNegation()

Whether this predicate has a predicate that is semantically its negation. For instance, Cmp.EQUAL and Cmp.NOT_EQUAL are negatives of each other.

Returns:

negate

JanusGraphPredicate negate()

Returns the negation of this predicate if it exists, otherwise an exception is thrown. Check hasNegation() first.

Specified by:

negate in interface BiPredicate<Object,Object>

Returns:

isQNF

boolean isQNF()

Returns true if this predicate is in query normal form.

Returns:

test

boolean test(Object value,
             Object condition)

Specified by:

test in interface BiPredicate<Object,Object>