/*
 * @(#)$Id: TREXGrammar.java,v 1.9 2001/10/12 01:36:59 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.trex;

import com.sun.msv.grammar.*;
import com.sun.msv.reader.datatype.DataTypeVocabularyMap;

/**
 * TREX grammar, which is expressed as <grammar> element.
 * 
 * <p>
 * The <code>exp</code> field keeps the start pattern.
 * 
 * @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
 */
public class TREXGrammar extends ReferenceExp implements Grammar{
	
	static final public class RefContainer extends ReferenceContainer {
		public ReferenceExp getOrCreate( String name ) {
			return super._getOrCreate(name);
		}
		protected ReferenceExp createReference( String name ) {
			return new ReferenceExp(name);
		}
	}
	
	/** named patterns which are defined by using <define> element.
	 * 
	 * this is a map from pattern name to RefPattern object
	 */
	public final RefContainer namedPatterns = new RefContainer();
	
	/** gets the start pattern.
	 * 
	 * The pattern defined under <start> element.
	 * This pattern will be used to verify document element.
	 */
	public Expression getTopLevel() { return this.exp; }
	
	/** ExpressionPool that is associated with this grammar */
	public final ExpressionPool pool;
	public ExpressionPool getPool() { return pool; }
	
	/** in case of nested grammar, this variable points to the parent grammar.
	 *  Otherwise null.
	 */
	protected final TREXGrammar parentGrammar;
	
	/**
	 * gets a parent TREXGrammar.
	 * 
	 * In case of nested grammar, the parent grammar will be returned.
	 * Otherwise, it returns null.
	 */
	public final TREXGrammar getParentGrammar() { return parentGrammar; }
	
	/**
	 * data type vocabularies used and defined by this grammar.
	 */
	public final DataTypeVocabularyMap dataTypes = new DataTypeVocabularyMap();
	
	/**
	 * 
	 * @param parentGrammar
	 *		this object is used to resolve <ref> element with parent
	 *		attribute.
	 */
	public TREXGrammar( ExpressionPool pool, TREXGrammar parentGrammar ) {
		super(null);
		this.pool = pool;
		this.parentGrammar = parentGrammar;
	}
	
	public TREXGrammar( ExpressionPool pool )	{ this(pool,null); }
	public TREXGrammar() { this(new ExpressionPool(),null); }
}