/* $Id: Namespace.java 17892 2010-01-12 21:21:35Z linus $
 *****************************************************************************
 * Copyright (c) 2009 Contributors - see below
 * 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:
 *    mvw
 *****************************************************************************
 *
 * Some portions of this file was previously release using the BSD License:
 */

// Copyright (c) 2003-2006 The Regents of the University of California. All
// Rights Reserved. Permission to use, copy, modify, and distribute this
// software and its documentation without fee, and without a written
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package org.argouml.uml.util.namespace;

import java.util.Iterator;

/**
 * The Namespace interface provides methods and constants which any class
 * dealing with namespaces needs to implement.
 *
 * @author mkl
 *
 */
public interface Namespace {

    /**
     * the scope token for java.
     */
    public static final String JAVA_NS_TOKEN = ".";

    /**
     * the scope token for uml.
     */
    public static final String UML_NS_TOKEN = "::";

    /**
     * the scope token for c++.
     */
    public static final String CPP_NS_TOKEN = "::";

    /**
     * returns the namespace which is common to both namespaces, e.g.
     * <code>org.argouml.model</code>
     * and <code>org.argouml.util</code> have <code>org.argouml</code> in
     * common.
     *
     * @param namespace
     *            a namespace
     * @return the common or empty namespace
     */
    Namespace getCommonNamespace(Namespace namespace);

    /**
     * returns the base of a namespace, e.g. the base of
     * <code>org.argouml.util</code>
     * is <code>org.argouml</code>.
     *
     * @return base namespace
     */
    Namespace getBaseNamespace();

    /**
     * add another element to a namespace.
     *
     * @param element the element to add
     */
    void pushNamespaceElement(NamespaceElement element);

    /**
     * reduces the innermost namespace element,
     * e.g. <code>org.argouml.model</code>
     * will return <code>model</code>, and change the namespace
     * to <code>org.argouml</code>.
     *
     * @return the popped element.
     */
    NamespaceElement popNamespaceElement();

    /**
     * return the innermost namespace element without removing it.
     *
     * @return the innermost namespace element
     */
    NamespaceElement peekNamespaceElement();

    /**
     * namespaces usually have a scope operator when used in representational
     * form. see also the predifined constants.
     *
     * @param token
     *            the token to use from now on.
     */
    void setDefaultScopeToken(String token);

    /**
     * return an iterator to the namespace elements.
     *
     * @return an iterator of NamespaceElements.
     */
    Iterator iterator();

    /**
     * check if the namespace is empty.
     *
     * @return true if empty
     */
    boolean isEmpty();

    /**
     * return a string representation of the namespace with the given token.
     * The existence of the method implies that classes also must implement
     * toString() in a reasonable manner using the default token.
     *
     * @param token the token to be converted
     * @return a string representation of the namespace
     */
    String toString(String token);
}