/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.jena.rdf.model;
import java.util.function.Predicate;
/** A Statement selector.
*
* <p>Model includes list and query methods which will return all the
* statements which are selected by a selector object. This is the interface
* of such selector objects.
*
*/
public interface Selector extends Predicate<Statement> {
/**
Answer true iff this Selector is completely characterised by its subject,
predicate, and object fields. If so, the <code>test</code> predicate need
not be called to decide if a statement is acceptable. This allows query engines
lattitude for optimisation (and our memory-based implementation both exploits
this licence).
*/
boolean isSimple();
/**
Answer the only subject Resource that this Selector will match, or null if it
can match more that a single resource.
*/
Resource getSubject();
/**
Answer the only predicate Property that this Selector will match, or null
if it can match more than a single property.
*/
Property getPredicate();
/**
Answer the only RDFNode object that this Selector will match, or null if
it can match more than a single node.
*/
RDFNode getObject();
}