* An escaped escape string is not treated as an escape string.
 *<li>
 * An escape string that does not precede a meta string (quotes or separator)
 * and is not at the end of a component is treated as an ordinary string.
 *<li>
 * A leading separator (the compound name string begins with
 * a separator) denotes a leading empty atomic component (consisting
 * of an empty string).
 * A trailing separator (the compound name string ends with
 * a separator) denotes a trailing empty atomic component.
 * Adjacent separators denote an empty atomic component.
 *</ol>
 * <p>
 * The string form of the compound name follows the syntax described above.
 * When the components of the compound name are turned into their
 * string representation, the reserved syntax rules described above are
 * applied (e.g. embedded separators are escaped or quoted)
 * so that when the same string is parsed, it will yield the same components
 * of the original compound name.
 *<p>
 *<h4>Multithreaded Access</h4>
 * A <tt>CompoundName</tt> instance is not synchronized against concurrent
 * multithreaded access. Multiple threads trying to access and modify a
 * <tt>CompoundName</tt> should lock the object.
 *
 * @author Rosanna Lee
 * @author Scott Seligman
 * @version 1.12 05/11/17
 * @since 1.3
 */

public class CompoundName implements Name {

    /**
      * Implementation of this compound name.
      * This field is initialized by the constructors and cannot be null.
      * It should be treated as a read-only variable by subclasses.
      */
    protected transient NameImpl impl;
    /**
      * Syntax properties for this compound name.
      * This field is initialized by the constructors and cannot be null.
      * It should be treated as a read-only variable by subclasses.
      * Any necessary changes to mySyntax should be made within constructors
      * and not after the compound name has been instantiated.
      */
    protected transient Properties mySyntax;

    /**
      * Constructs a new compound name instance using the components
      * specified in comps and syntax. This protected method is intended to be
      * to be used by subclasses of CompoundName when they override
      * methods such as clone(), getPrefix(), getSuffix().
      *
      * @param comps  A non-null enumeration of the components to add.
      *   Each element of the enumeration is of class String.
      *               The enumeration will be consumed to extract its
      *               elements. 
      * @param syntax	A non-null properties that specify the syntax of
      *			this compound name. See class description for
      *			contents of properties.
      */
    protected CompoundName(Enumeration<String> comps, Properties syntax) {
	if (syntax == null) {
	    throw new NullPointerException();
	}
	mySyntax = syntax;
	impl = new NameImpl(syntax, comps);
    }

    /**
      * Constructs a new compound name instance by parsing the string n
      * using the syntax specified by the syntax properties supplied.
      *
      * @param	n	The non-null string to parse.
      * @param syntax	A non-null list of properties that specify the syntax of
      *			this compound name.  See class description for
      *			contents of properties.
      * @exception	InvalidNameException If 'n' violates the syntax specified
      *			by <code>syntax</code>.
      */
    public CompoundName(String n, Properties syntax) throws InvalidNameException {
	if (syntax == null) {
	    throw new NullPointerException();
	}
	mySyntax = syntax;
	impl = new NameImpl(syntax, n);
    }

    /**
      * Generates the string representation of this compound name, using
      * the syntax rules of the compound name. The syntax rules
      * are described in the class description.
      * An empty component is represented by an empty string.
      *
      * The string representation thus generated can be passed to
      * the CompoundName constructor with the same syntax properties
      * to create a new equivalent compound name.
      *
      * @return A non-null string representation of this compound name.