text: /****************************************************************************
  **
  ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
  ** All rights reserved.
  ** Contact: Nokia Corporation (qt-info@nokia.com)
  **
  ** This file is part of the QtXmlPatterns module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
  ** GNU Lesser General Public License Usage
  ** This file may be used under the terms of the GNU Lesser General Public
  ** License version 2.1 as published by the Free Software Foundation and
  ** appearing in the file LICENSE.LGPL included in the packaging of this
  ** file. Please review the following information to ensure the GNU Lesser
  ** General Public License version 2.1 requirements will be met:
  ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
  **
  ** In addition, as a special exception, Nokia gives you certain additional
  ** rights. These rights are described in the Nokia Qt LGPL Exception
  ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
  **
  ** GNU General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU General
  ** Public License version 3.0 as published by the Free Software Foundation
  ** and appearing in the file LICENSE.GPL included in the packaging of this
  ** file. Please review the following information to ensure the GNU General
  ** Public License version 3.0 requirements will be met:
  ** http://www.gnu.org/copyleft/gpl.html.
  **
  ** Other Usage
  ** Alternatively, this file may be used in accordance with the terms and
  ** conditions contained in a signed written agreement between you and Nokia.
  **
  **
  **
  **
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/
  
  //
  //  W A R N I N G
  //  -------------
  //
  // This file is not part of the Qt API.  It exists purely as an
  // implementation detail.  This header file may change from version to
  // version without notice, or even be removed.
  //
  // We mean it.
  
  #ifndef Patternist_EmptySequence_H
  #define Patternist_EmptySequence_H
  
  #include "qemptycontainer_p.h"
  
  QT_BEGIN_HEADER
  
  QT_BEGIN_NAMESPACE
  
  namespace QPatternist
  {
      /**
       * @short Implements the value instance of empty sequence: <tt>()</tt>.
       *
       * @author Frans Englich <frans.englich@nokia.com>
       * @ingroup Patternist_xdm
       */
      class EmptySequence : public EmptyContainer
      {
      public:
          /**
           * @short Creates an EmptySequence that is a replacement for @p
           * replacementFor.
           *
           * @see EmptySequence()
           */
          static Expression::Ptr create(const Expression *const replacementFor,
                                        const StaticContext::Ptr &context);
  
  
          /**
           * @short Creates an instance of EmptySequence.
           *
           * @note In most cases create() should be used, since it takes care of
           * adjusting source location annotations.
           *
           * @see create()
           */
          inline EmptySequence()
          {
          }
  
          virtual QString stringValue() const;
  
          /**
           * @returns always an empty iterator, an instance of EmptyIterator.
           */
          virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &) const;
  
          /**
           * @returns always @c null.
           */
          virtual Item evaluateSingleton(const DynamicContext::Ptr &) const;
  
          /**
           * Does nothing.
           */
          virtual void evaluateToSequenceReceiver(const DynamicContext::Ptr &) const;
  
          /**
           * @returns always @c false.
           */
          virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;
  
          /**
           * @returns always CommonSequenceTypes::Empty
           */
          virtual ItemType::Ptr type() const;
  
          /**
           * @returns always CommonSequenceTypes::Empty
           */
          virtual SequenceType::Ptr staticType() const;
  
          virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
          virtual ID id() const;
          virtual Properties properties() const;
      };
  }
  
  QT_END_NAMESPACE
  
  QT_END_HEADER
  
  #endif
  