/*
* xtc - The eXTensible Compiler
* Copyright (C) 2004-2007 Robert Grimm
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
* USA.
*/
package xtc.parser;
import java.io.IOException;
/**
* An optional grammar element.
*
* @author Robert Grimm
* @version $Revision: 1.9 $
*/
public class Option extends Quantification {
/**
* Create a new option.
*
* @param element The optional grammar element.
*/
public Option(Element element) {
super(element);
}
public Tag tag() {
return Tag.OPTION;
}
public int hashCode() {
return element.hashCode();
}
public boolean equals(Object o) {
if (this == o) return true;
if (! (o instanceof Option)) return false;
return element.equals(((Option)o).element);
}
public void write(Appendable out) throws IOException {
element.write(out);
out.append('?');
}
}