com.sun.msv.grammar.util.RefExpRemover Maven / Gradle / Ivy
/*
* @(#)$Id: RefExpRemover.java,v 1.5 2003/06/09 20:37:21 kk122374 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.util;
import java.util.Set;
import com.sun.msv.grammar.AttributeExp;
import com.sun.msv.grammar.ElementExp;
import com.sun.msv.grammar.Expression;
import com.sun.msv.grammar.ExpressionCloner;
import com.sun.msv.grammar.ExpressionPool;
import com.sun.msv.grammar.OtherExp;
import com.sun.msv.grammar.ReferenceExp;
/**
* removes all ReferenceExp from AGM.
*
* when named expression is nullSet, it cannot be used.
* by replacing ReferenceExp by its definition, those unavailable expressions
* will be properly removed from AGM.
*
* @author Kohsuke KAWAGUCHI
*/
public class RefExpRemover extends ExpressionCloner {
/** set of visited ElementExps */
private final Set visitedElements = new java.util.HashSet();
private final boolean recursive;
/**
* @param _recursive
*
* If true, this object behaves destructively. It recursively
* visits all the reachable expressions and removes ReferenceExps.
* In this process, this object changes the content model of
* ElementExps.
*
*
* If false, this object doesn't visit the content models of child
* elements, therefore, it behaves non-destructively. Nothing in the
* original expression will be touched.
*/
public RefExpRemover(ExpressionPool pool, boolean _recursive) {
super(pool);
this.recursive = _recursive;
}
public Expression onElement(ElementExp exp) {
if (!recursive)
// do not touch child elements.
return exp;
if (!visitedElements.contains(exp)) {
// remove refs from this content model
visitedElements.add(exp);
exp.contentModel = exp.contentModel.visit(this);
}
if (exp.contentModel == Expression.nullSet)
return Expression.nullSet; // this element is not allowed
else
return exp;
}
public Expression onAttribute(AttributeExp exp) {
Expression content = exp.exp.visit(this);
if (content == Expression.nullSet)
return Expression.nullSet; // this attribute is not allowed
else
return pool.createAttribute(exp.nameClass, content);
}
public Expression onRef(ReferenceExp exp) {
return exp.exp.visit(this);
}
public Expression onOther(OtherExp exp) {
return exp.exp.visit(this);
}
}