/**
 * A very simple entry for a dictionary.  Note that while you can
 * change the value associated with an entry, you may not change
 * the key used.  This restriction simplifies the implementation of
 * dictionaries.
 *
 * @author Samuel A. Rebelsky
 * @version 1.0 of April 2000
 */
public class Entry {

    // +--------+----------------------------------------
    // | Fields |
    // +--------+

    /** The key of the entry.  Should never be null. */
    private Object key;

    /** 
     * The associated value.  May be null, although I'm not
     * sure what that would signify. 
     */
    private Object value;

    // +--------------+----------------------------------
    // | Constructors |
    // +--------------+

    /**  
     * Build a new entry for the table.
     */
    public Entry(Object finalKey, Object initialValue) {
        this.key = finalKey;
        this.value = initialValue;
    } // Entry(Object, Object)

    // +-----------+-------------------------------------
    // | Modifiers |
    // +-----------+

    /**
     * Change the value associated with a particular key.
     */
    public void setValue(Object newValue) {
        this.value = newValue;
    } // setValue(Object)

    // +------------+------------------------------------
    // | Extractors |
    // +------------+

    /**
     * Determine if this has the same key as another entry.
     */
    public boolean equals(Entry otherEntry) {
        return this.key.equals(otherEntry.key);
    } // equals(Entry)

    /**
     * Determine if this entry equals another object.  The
     * entry is only equal to another object if that object
     * is an entry with an equal key.
     */
    public boolean equals(Object other) {
        if (other instanceof Entry) {
            return this.equals((Entry) other);
        } // the other thing is an entry
        else {
            return false;
        } // the other thing is not an entry
    } // equals(Object)

    /**
     * Get the key of this entry.
     */
    public Object getKey() {
        return this.key;
    } // getKey()

    /**
     * Get the value of this entry.
     */
    public Object getValue() {
        return this.value;
    } // getValue()

    /**
     * Get the hash code of this entry.
     */
    public int hashCode() {
        return this.key.hashCode();
    } // hashCode()

} // class Entry