FlatTuple.java

/*******************************************************************************
 * Copyright (c) 2004-2008 Gabor Bergmann and Daniel Varro
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Gabor Bergmann - initial API and implementation
 *******************************************************************************/

package org.eclipse.incquery.runtime.rete.tuple;

import java.util.Arrays;

/**
 * @author Gabor Bergmann Default Tuple implementation
 */
public class FlatTuple extends Tuple {

    /**
     * Array of substituted values. DO NOT MODIFY! Use Constructor to build a new instance instead.
     */
    private final Object[] elements;

    /**
     * Creates a Tuple instance, fills it with the given array. @pre: no elements are null
     * 
     * @param elements
     *            array of substitution values
     */
    public FlatTuple(Object[] elements) {
        this.elements = elements;
        calcHash();
    }

    /**
     * Creates a Tuple instance of size one, fills it with the given object.
     * 
     * @pre: o!=null
     * 
     * @param o
     *            the single substitution
     */
    public FlatTuple(Object o) {
        elements = new Object[1];
        elements[0] = o;
        calcHash();
    }

    /**
     * Creates a Tuple instance of size two, fills it with the given objects.
     * 
     * @pre: o1!=null, o2!=null
     */
    public FlatTuple(Object o1, Object o2) {
        elements = new Object[2];
        elements[0] = o1;
        elements[1] = o2;
        calcHash();
    }

    /**
     * Creates a Tuple instance of size three, fills it with the given objects.
     * 
     * @pre: o1!=null, o2!=null, o3!=null
     */
    public FlatTuple(Object o1, Object o2, Object o3) {
        elements = new Object[3];
        elements[0] = o1;
        elements[1] = o2;
        elements[2] = o3;
        calcHash();
    }

    @Override
    public Object get(int index) {
        return elements[index];
    }

    @Override
    public int getSize() {
        return elements.length;
    }

    @Override
    public Object[] getElements() {
        return elements;
    }

    @Override
    protected boolean internalEquals(Tuple other) {
        if (other instanceof FlatTuple) {
            return Arrays.equals(elements, ((FlatTuple) other).elements);
        } else
            return super.internalEquals(other);
    }

}