/**
* Copyright (c) 2002-2010 "Neo Technology,"
* Network Engine for Objects in Lund AB [http://neotechnology.com]
*
* This file is part of Neo4j.
*
* Neo4j is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.neo4j.graphdb.traversal;
import org.neo4j.graphdb.Path;
/**
* An evaluator which can "cut off" relationships so that they will not be
* traversed in the ongoing traversal. For any given position a prune evaluator
* can decide whether or not to prune whatever is beyond (i.e. after) that
* position or not.
*/
public interface PruneEvaluator
{
/**
* Default {@link PruneEvaluator}, does not prune any parts of the
* traversal.
*/
static final PruneEvaluator NONE = new PruneEvaluator()
{
public boolean pruneAfter( Path position )
{
return false;
}
};
/**
* Decides whether or not to prune after {@code position}. If {@code true}
* is returned the position won't be expanded and traversals won't be made
* beyond that position.
*
* @param position the {@link Path position} to decide whether or not to
* prune after.
* @return whether or not to prune after {@code position}.
*/
boolean pruneAfter( Path position );
}