001    /*
002    // $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/QueryPart.java#1 $
003    // This software is subject to the terms of the Eclipse Public License v1.0
004    // Agreement, available at the following URL:
005    // http://www.eclipse.org/legal/epl-v10.html.
006    // Copyright (C) 1998-2002 Kana Software, Inc.
007    // Copyright (C) 2001-2009 Julian Hyde and others
008    // All Rights Reserved.
009    // You must accept the terms of that agreement to use this software.
010    //
011    // jhyde, 23 January, 1999
012    */
013    
014    package mondrian.olap;
015    import java.io.PrintWriter;
016    
017    /**
018     * Component of an MDX query (derived classes include Query, Axis, Exp, Level).
019     *
020     * @version $Id: //open/mondrian-release/3.2/src/main/mondrian/olap/QueryPart.java#1 $
021     * @author jhyde
022     */
023    public abstract class QueryPart implements Walkable {
024        /**
025         * Creates a QueryPart.
026         */
027        QueryPart() {
028        }
029    
030        /**
031         * Writes a string representation of this parse tree
032         * node to the given writer.
033         *
034         * @param pw writer
035         */
036        public void unparse(PrintWriter pw) {
037            pw.print(toString());
038        }
039    
040        // implement Walkable
041        public Object[] getChildren() {
042            // By default, a QueryPart is atomic (has no children).
043            return null;
044        }
045    }
046    
047    // End QueryPart.java