/**
 * AmbientTalk/2 Project
 * ATMessageSend.java created on 26-jul-2006 at 14:58:25
 * (c) Programming Technology Lab, 2006 - 2007
 * Authors: Tom Van Cutsem & Stijn Mostinckx
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */
package edu.vub.at.objects.grammar;

import edu.vub.at.objects.ATNil;

/**
 * The public interface to a synchronous or asynchronous message send AG element.
 * 
 * Message sends of the form <code>o.m()</code> are transformed into <MESSAGE-SEND o <METHOD-INVOCATION m []>>
 * Message sends of the form <code>o<-m()</code> are transformed into <MESSAGE-SEND o <ASYNC-MESSAGE m []>>
 * Message sends of the form <code>o^m()</code> are transformed into <MESSAGE-SEND o <DELEGATION m []>>
 * Message sends of the form <code>o<+exp</code> are transformed into <MESSAGE-SEND o <EXPRESSION exp>>
 * 
 * @author tvcutsem
 */
public interface ATMessageSend extends ATExpression {

	/**
	 * The receiver may be any valid AmbientTalk expression
	 * Example: <code>`(f().m()).getReceiverExpression() == `(f())</code>
	 * @return the receiver of the message
	 */
	public ATExpression base_getReceiverExpression();
	
	/**
	 * @param rcv the new receiver
	 * @return nil
	 */
	public ATNil base_setReceiverExpression(ATExpression rcv);
	
	/**
	 * The message to be sent must be an AmbientTalk expression that evaluates
	 * to a message.
	 * Example: <code>`(f().m()).getMessageExpression() == `(.m())</code>
	 * @return the message expression
	 */
	public ATExpression base_getMessageExpression();
	
}