/*
 ***** BEGIN LICENSE BLOCK *****
 * Version: EPL 1.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 1.0 (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.eclipse.org/legal/epl-v10.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2001-2002 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
 * Copyright (C) 2004-2005 Thomas E Enebo <enebo@acm.org>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/
package org.jruby.ast;

import org.jruby.ast.types.IArityNode;
import org.jruby.lexer.yacc.ISourcePosition;
import org.jruby.runtime.Arity;

/**
 * Base class of any node which can be assigned to.
 */
public abstract class AssignableNode extends Node implements IArityNode {
    private Node valueNode;
    
    public AssignableNode(ISourcePosition position) {
        super(position);
    }
    
    public AssignableNode(ISourcePosition position, Node valueNode) {
        super(position);
        
        assert valueNode != null : "valueNode is not null";
        
        this.valueNode = valueNode;
    }
    
    /**
     * Gets the valueNode.
     * @return Returns a Node
     */
    public Node getValueNode() {
        return valueNode;
    }
    
    /**
     * Sets the valueNode.
     * @param valueNode The valueNode to set
     */
    public void setValueNode(Node valueNode) {
        this.valueNode = valueNode == null ? NilImplicitNode.NIL : valueNode;
    }
    
    /**
     * Almost all assignables are only assigned a single value.
     */
    public Arity getArity() {
        return Arity.singleArgument();
    }
}
