/*
 * @(#)$Id: AttributeExp.java,v 1.12 2001/10/19 23:30:09 Bear Exp $
 *
 * Copyright 2001 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * This software is the proprietary information of Sun Microsystems, Inc.  
 * Use is subject to license terms.
 * 
 */
package com.sun.msv.grammar;

/**
 * Attribute declaration.
 * 
 * <p>
 * Attribute declaration consists of a NameClass that verifies attribute name
 * and an Expression that verifies the value of the attribute.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class AttributeExp extends Expression implements NameClassAndExpression {
	
	/** constraint over attribute name */
	public final NameClass nameClass;
	public final NameClass getNameClass() { return nameClass; }
	
	/** child expression */
	public final Expression exp;
	public final Expression getContentModel() { return exp; }
	
	public AttributeExp( NameClass nameClass, Expression exp ) {
		super( hashCode( nameClass, exp, HASHCODE_ATTRIBUTE ) );
		this.nameClass	= nameClass;
		this.exp		= exp;
	}
	
	public boolean equals( Object o ) {
		return this==o;
//		if(!(o instanceof AttributeExp))	return false;
//		return ((AttributeExp)o).nameClass.equals(nameClass)
//			&& ((AttributeExp)o).exp.equals(exp);
	}
	
	public Object visit( ExpressionVisitor visitor )				{ return visitor.onAttribute(this);	}
	public Expression visit( ExpressionVisitorExpression visitor )	{ return visitor.onAttribute(this); }
	public boolean visit( ExpressionVisitorBoolean visitor )		{ return visitor.onAttribute(this);	}
	public void visit( ExpressionVisitorVoid visitor )				{ visitor.onAttribute(this);	}
	
	protected boolean calcEpsilonReducibility() {
		return false;
	}
}