LR0Item.java

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 * This file is part of SableCC.                             *
 * See the file "LICENSE" for copyright information and the  *
 * terms and conditions for copying, distribution and        *
 * modification of SableCC.                                  *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package org.sablecc.sablecc;

import java.util.StringTokenizer;

@SuppressWarnings("rawtypes")
final class LR0Item implements Cloneable, Comparable {
    final int production;
    final int position;

    LR0Item(int production, int position) {
        this.production = production;
        this.position = position;
    }

    @Override
    public int compareTo(Object object) {
        LR0Item item = (LR0Item) object;

        int result = production - item.production;

        if (result == 0) {
            result = position - item.position;
        }

        return result;
    }

    @Override
    public Object clone() {
        return new LR0Item(production, position);
    }

    @Override
    public boolean equals(Object obj) {
        if ((obj == null) ||
                (obj.getClass() != this.getClass())) {
            return false;
        }

        LR0Item item = (LR0Item) obj;

        return (item.production == production) &&
                (item.position == position);
    }

    @Override
    public int hashCode() {
        return (production * 13) ^ (position * 17);
    }

    @Override
    public String toString() {
        StringBuffer result = new StringBuffer();
        String prodStr = (Production.production(production)).toString();
        int pos = 0;

        StringTokenizer list = new StringTokenizer(prodStr, "= ");

        // we know that there is at least one token (lhs)
        result.append(list.nextToken());
        result.append(" =");

        while (list.hasMoreElements()) {
            String tmp = list.nextToken();

            if (pos == position) {
                result.append(" * ");
                result.append(tmp);
            } else {
                result.append(" ");
                result.append(tmp);
            }

            pos++;
        }

        if (pos == position) {
            result.append(" *");
        }

        return "[ " + result + " ]";
    }
}