/*
* 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.util.ArrayList;
import java.util.List;
/**
* An ordered choice of grammar elements.
*
* @author Robert Grimm
* @version $Revision: 1.14 $
*/
public class OrderedChoice extends Element {
/** The ordered list of sequences. */
public List<Sequence> alternatives;
/** Create a new ordered choice with no choices. */
public OrderedChoice() {
this.alternatives = new ArrayList<Sequence>();
}
/**
* Create a new ordered choice.
*
* @param alternatives The list of alternatives.
*/
public OrderedChoice(List<Sequence> alternatives) {
this.alternatives = alternatives;
}
/**
* Create a new ordered choice with the specified element as its
* only alternative. The constructor {@link
* Sequence#ensure(Element) ensures} that the element is a sequence.
* It also copies the element's location into the newly created
* choice.
*
* @param element The element.
*/
public OrderedChoice(Element element) {
alternatives = new ArrayList<Sequence>(1);
alternatives.add(Sequence.ensure(element));
setLocation(element);
}
public Tag tag() {
return Tag.CHOICE;
}
public int hashCode() {
return alternatives.hashCode();
}
public boolean equals(Object o) {
if (this == o) return true;
if (! (o instanceof OrderedChoice)) return false;
return alternatives.equals(((OrderedChoice)o).alternatives);
}
}