org.apache.jena.sparql.syntax.Element Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of jena-arq Show documentation
Show all versions of jena-arq Show documentation
ARQ is a SPARQL 1.1 query engine for Apache Jena
/*
* 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.sparql.syntax;
import org.apache.jena.sparql.serializer.FormatterElement ;
import org.apache.jena.sparql.util.NodeIsomorphismMap ;
/** Element - abstract class for all pattern elements */
public abstract class Element
{
public abstract void visit(ElementVisitor v) ;
@Override
public abstract int hashCode() ;
// If the labelMap is null, do .equals() on nodes, else map from
// bNode varables in one to bNodes variables in the other
public abstract boolean equalTo(Element el2, NodeIsomorphismMap isoMap) ;
@Override
final public boolean equals(Object el2)
{
if ( this == el2 ) return true ;
if ( ! ( el2 instanceof Element ) )
return false ;
return equalTo((Element)el2, null) ;
}
@Override
public String toString()
{
return FormatterElement.asString(this) ;
}
// Constants used in hashing to stop an element and it's subelement
// (if just one) having the same hash.
static final int HashBasicGraphPattern = 0xA1 ;
static final int HashGroup = 0xA2 ;
static final int HashUnion = 0xA3 ;
static final int HashOptional = 0xA4 ;
// static final int HashGraph = 0xA5 ; // Not needed
static final int HashExists = 0xA6 ;
static final int HashNotExists = 0xA7 ;
static final int HashPath = 0xA8 ;
static final int HashFetch = 0xA9 ;
}