/*
This file is part of the algoviz@vt collection of algorithm
visualizations.

This program is free software: you can redistribute it and/or
modify it under the terms of the GNU General Public License as
published by the Free Software Foundation, either version 3
of the License, or (at your option) any later version.

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 distribution. If not, see
<http://www.gnu.org/licenses/>.
*/

/**
 * Binary Node Abstract Data Type.
 * 
 * @author Andrew Whitaker (aawhitak)
 * 
 * Developed for Undergraduate Research Spring '08 for the Algorithm
 * Visualizations project.
 * 
 * @param <T>
 */

public interface BinNodeADT<T, E>
{
    T key();

    /**
     * @return The value held by this node.
     */
    E val();

    /**
     * Sets the value in this node.
     * 
     * @param val
     *                The new value to give the node.
     */
    void setVal(E val);

    /**
     * @return This node's left child, null if it doesn't exist.
     */
    BinNodeADT<T, E> left();

    /**
     * @return This node's right child, null if it doesn't exist.
     */
    BinNodeADT<T, E> right();

    /**
     * Sets the left child of this node.
     * 
     * @param l
     *                The new left child.
     */
    void setLeft(BinNodeADT<T, E> l);

    /**
     * Sets the right child of this node.
     * 
     * @param r
     *                The new right child.
     */
    void setRight(BinNodeADT<T, E> r);

    /**
     * @return True if this node is a leaf (has no children), false otherwise.
     */
    boolean isLeaf();
}