/*
* @(#)$Id: OccurrenceExp.java,v 1.1 2002/07/26 21:50:13 kk122374 Exp $
*
* Copyright 2002 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.xmlschema;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.OtherExp;
/**
* Used to mark a occurrence constraint which cannot
* be easily represented by primitive expressions.
*
* <p>
* This expression is just a marker, and the exp field
* of this instance still contains the precise expression
* of the occurrence constraint.
*
* <p>
* For example, if A is maxOccurs=5 and minOccurs=3,
* then the exp field of this instance will be:
* <code>A,A,A,(A,A?)?</code>, the maxOccurs field
* will be 5, the minOccurs field will be 3, and
* the itemExp field will hold a reference to <code>A</code>.
*
* <p>
* Note that MSV doesn't using this marker by itself.
* It is intended to help other applications that use
* the AGM of MSV.
*
* <p>
* Also note that this expression will not
* be used in the following cases to avoid excessive allocation
* of this expression:
*
* <ul>
* <li>when maxOccurs=unbounded and minOccurs is 1 or 0
* <li>when maxOccurs=1
* </ul>
*
* <p>
* Those cases can be expressed quite nicely with existing primitives
* So the client shouldn't find it difficuult to process them.
* I appreciate any feedback on this issue.
*
* @author
* Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
*/
public class OccurrenceExp extends OtherExp {
public OccurrenceExp(
Expression preciseExp,
int maxOccurs, int minOccurs, Expression itemExp ) {
super(preciseExp);
this.maxOccurs = maxOccurs;
this.minOccurs = minOccurs;
this.itemExp = itemExp;
}
/** Maximum occurence. -1 to indicate "unbounded" */
public final int maxOccurs;
/** Minimum occurence. -1 to indicate "unbounded" */
public final int minOccurs;
/**
* The unit of repetition.
*/
public final Expression itemExp;
}