Subversion Repositories mkgmap

/*
 * Copyright (C) 2008 Steve Ratcliffe
 *
 *  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.
 *
 *
 * Author: Steve Ratcliffe
 * Create date: 08-Nov-2008
 */
package uk.me.parabola.mkgmap.osmstyle.eval;

import uk.me.parabola.mkgmap.reader.osm.Element;
import uk.me.parabola.mkgmap.scan.SyntaxException;

/**
 * An open parenthesis.  This is treated specially.
 * @author Steve Ratcliffe
 */
public class OpenOp extends AbstractOp {

        public OpenOp() {
                setType(NodeType.OPEN_PAREN);
        }

        public boolean eval(Element el) {
                throw new SyntaxException("Programming error, trying to eval an open parenthesis");
        }

        /**
         * This is used when placing this on the top of the stack, for that
         * purpose it has a very high priority and will not cause anything
         * below to execute.
         */
        public int priority() {
                return 100;
        }

        /**
         * This is called when it is on the top of the stack.  In this case all
         * other operations have a higher priority.
         * @param other The other operation.
         * @return Always returns false.
         */
        public boolean hasHigherPriority(Op other) {
                return false;
        }
}