org.janusgraph.graphdb.query.JanusGraphPredicate Maven / Gradle / Ivy
// Copyright 2017 JanusGraph Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package org.janusgraph.graphdb.query;
import org.janusgraph.core.attribute.Cmp;
import java.util.function.BiPredicate;
/**
* A special kind of {@link 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 {@link BiPredicate} implementations to the corresponding JanusGraph predicates.
*
* @author Matthias Broecheler ([email protected])
*/
public interface JanusGraphPredicate extends BiPredicate {
/**
* Whether the given condition is a valid condition for this predicate.
*
* For instance, the {@link Cmp#GREATER_THAN} would require that the condition is comparable and not null.
*
* @param condition
* @return
*/
boolean isValidCondition(Object condition);
/**
* Whether the given class is a valid data type for a value to which this predicate may be applied.
*
* For instance, the {@link Cmp#GREATER_THAN} can only be applied to {@link Comparable} values.
*
* @param clazz
* @return
*/
boolean isValidValueType(Class clazz);
/**
* Whether this predicate has a predicate that is semantically its negation.
* For instance, {@link Cmp#EQUAL} and {@link Cmp#NOT_EQUAL} are negatives of each other.
*
* @return
*/
boolean hasNegation();
/**
* Returns the negation of this predicate if it exists, otherwise an exception is thrown. Check {@link #hasNegation()} first.
* @return
*/
@Override
JanusGraphPredicate negate();
/**
* Returns true if this predicate is in query normal form.
* @return
*/
boolean isQNF();
@Override
boolean test(Object value, Object condition);
}