Class StringWme

Java/SMLJava/src/main/java/edu/umich/soar/StringWme.java:12–118

Wrapper for String valued working memory elements. @author voigtjr

 * 
 */
public class StringWme implements Wme
{
    /**
     * Create working memory element instance with no value. The value will be
     * set (and underlying SML Wme created) on first update.
     * 
     * @param parent
     *            Parent identifier
     * @param attr
     *            Attribute
     * @return Wme ready for update
     */
    public static StringWme newInstance(Identifier parent, String attr)
    {
        return new StringWme(parent, attr);
    }

    /**
     * Create working memory element instance with known initial value.
     * 
     * @param parent
     *            Parent identifier
     * @param attr
     *            Attribute
     * @param val
     *            Initial value
     * @return Wme ready for update
     */
    public static StringWme newInstance(Identifier parent, String attr,
            String val)
    {
        StringWme temp = new StringWme(parent, attr);
        temp.update(val);
        return temp;
    }

    private final Identifier parent;

    private final String attr;

    private StringElement wme;

    private StringWme(Identifier parent, String attr)
    {
        this.parent = parent;
        this.attr = attr;
    }

    /**
     * <p>
     * Update to possibly new value. See Agent.BlinkIfNoChange()
     * 
     * @param val
     *            The new value
     * @throws NullPointerException
     *             if val is null
     */
    public void update(String val)