/*
 * Copyright (c) 2007 BUSINESS OBJECTS SOFTWARE LIMITED
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     * Redistributions of source code must retain the above copyright notice,
 *       this list of conditions and the following disclaimer.
 *  
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *  
 *     * Neither the name of Business Objects nor the names of its contributors
 *       may be used to endorse or promote products derived from this software
 *       without specific prior written permission.
 *  
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */


/*
 * ValueNodeTransformer.java
 * Creation date: (19/07/01 1:12:24 PM)
 * By: Michael Cheng
 */
package org.openquark.cal.valuenode;

import org.openquark.cal.compiler.TypeExpr;

/**
 * A ValueNodeTransformer's purpose is to transform (transfer data) between
 * two ValueNodes (as long as they are compatible).
 * Creation date: (19/07/01 1:12:24 PM)
 * @author Michael Cheng
 */
public interface ValueNodeTransformer {

    /**
     * Will return a new ValueNode ideally suited for handling targetTypeExpr.
     * If the sourceVN and the returned ValueNode are of a recognized 'data transferable'
     * combination, then the sourceVN's data value will be moved to the returned ValueNode 
     * (perhaps with some minor mutations like rounding numbers).
     */
    public ValueNode transform(ValueNodeBuilderHelper valueNodeBuilderHelper, ValueNode sourceVN, TypeExpr targetTypeExpr);
}