/*
* Copyright 2008 Fedora Commons
*
* 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.mulgara.sparql.parser;
import org.mulgara.sparql.parser.cst.BlankNode;
/**
* This class allocated names for anonymous variables used for indicating blank nodes in queries.
*
* @created Feb 19, 2008
* @author Paula Gearon
* @copyright © 2008 <a href="http://www.fedora-commons.org/">Fedora Commons</a>
* @licence <a href="{@docRoot}/../LICENCE.txt">Apache License, Version 2.0</a>
*/
public class VarNameAllocator {
/** A marker for variable names that is not valid in any query syntax */
private static final String ANON_MARKER = "*";
/** An incrementing value to make names unique */
private int counter = 0;
/**
* Create a unique BlankNode.
* @return The new blank node.
*/
public BlankNode allocate() {
return new BlankNode(ANON_MARKER + counter++);
}
/**
* Get the name for a new blank node.
* @return A unique name for a blank node.
*/
public String allocateName() {
return ANON_MARKER + counter++;
}
}