/*
* @(#)$Id: SequenceState.java,v 1.6 2001/05/01 18:13:02 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.reader;
import com.sun.msv.grammar.Expression;
/**
* state that creates SequenceExp.
*
* @author <a href="mailto:kohsuke.kawaguchi@eng.sun.com">Kohsuke KAWAGUCHI</a>
*/
public class SequenceState extends ExpressionWithChildState {
public SequenceState() {
this(false);
}
public SequenceState( boolean allowEmptySequence ) {
this.allowEmptySequence = allowEmptySequence;
}
protected boolean allowEmptySequence;
protected Expression initialExpression() {
return allowEmptySequence?Expression.epsilon:null;
}
protected Expression castExpression( Expression exp, Expression child ) {
// first one.
if( exp==null ) return child;
return reader.pool.createSequence(exp,child);
}
}