LR0ItemSet.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.Iterator;
import java.util.TreeMap;
import java.util.Vector;

@SuppressWarnings({"rawtypes", "unchecked"})
final class LR0ItemSet implements Cloneable, Comparable {
    private final TreeMap items;
    private int hashCode;

    LR0ItemSet() {
        items = new TreeMap();
    }

    private LR0ItemSet(LR0ItemSet set
    ) {
        items = (TreeMap) set.items.clone();
    }

    void set
            (LR0Item item) {
        if (items.put(item, item) == null) {
            hashCode += item.hashCode();
            modified_ = true;
        }
    }

    boolean get
            (LR0Item item) {
        return items.get(item) != null;
    }

    LR0Item[] items_;
    boolean modified_ = true;

    private void computeArray() {
        Vector itemVector = new Vector(0);

        for (Iterator e = items.keySet().iterator(); e.hasNext(); ) {
            itemVector.addElement(e.next());
        }

        items_ = new LR0Item[itemVector.size()];
        itemVector.copyInto(items_);
        modified_ = false;
    }

    LR0Item[] items() {
        if (modified_) {
            computeArray();
        }

        return items_;
    }

    @Override
    public String toString() {
        StringBuffer result = new StringBuffer();
        result.append("{");

        Production[] productions = Production.productions();
        boolean space = false;
        for (int i = 0; i < productions.length; i++) {
            int rightsideLength = productions[i].rightside().length;

            for (int j = 0; j <= rightsideLength; j++) {
                LR0Item item = new LR0Item(productions[i].index, j);
                if (get
                        (item)) {
                    if (space) {
                        result.append(",");
                    } else {
                        space = true;
                    }

                    result.append(item);
                }
            }

        }

        result.append("}");
        return result.toString();
    }

    @Override
    public Object clone() {
        return new LR0ItemSet(this);
    }

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

        LR0ItemSet set
                = (LR0ItemSet) obj;

        if (set.items.size() != items.size()) {
            return false;
        }

        for (Iterator e = items.keySet().iterator(); e.hasNext(); ) {
            if (!set.get((LR0Item) e.next())) {
                return false;
            }
        }

        return true;
    }

    @Override
    public int hashCode() {
        return hashCode;
    }

    @Override
    public int compareTo(Object object) {
        LR0ItemSet set
                = (LR0ItemSet) object;

        int result = items.size() - set.items.size();

        if (result == 0) {
            Iterator e = items.keySet().iterator();
            Iterator f = set.items.keySet().iterator();

            while (e.hasNext() && f.hasNext() && (result == 0)) {
                result = ((LR0Item) e.next()).compareTo(f.next());
            }

            if (result == 0) {
                if (e.hasNext()) {
                    return 1;
                }

                if (f.hasNext()) {
                    return -1;
                }
            }
        }

        return result;
    }

}