text: /****************************************************************************
  **
  ** Copyright (C) 2016 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the QtXmlPatterns module of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:LGPL$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
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  **
  ** GNU Lesser General Public License Usage
  ** Alternatively, this file may be used under the terms of the GNU Lesser
  ** General Public License version 3 as published by the Free Software
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  ** packaging of this file. Please review the following information to
  ** ensure the GNU Lesser General Public License version 3 requirements
  ** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
  **
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  ** Alternatively, this file may be used under the terms of the GNU
  ** General Public License version 2.0 or (at your option) the GNU General
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  ****************************************************************************/
  
  //
  //  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_OptimizationBlocks_H
  #define Patternist_OptimizationBlocks_H
  
  #include <private/qatomiccomparator_p.h>
  #include <private/qexpression_p.h>
  #include <private/qoptimizerframework_p.h>
  
  QT_BEGIN_NAMESPACE
  
  namespace QPatternist
  {
      /**
       * @short Contains a set of common OptimizerPass instances.
       *
       * @author Frans englich <frans.englich@nokia.com>
       * @ingroup Patternist_expressions
       */
      namespace OptimizationPasses
      {
          /**
           * A list of OptimizerPass instances that performs the
           * following rewrites:
           *
           * - <tt>count([expr]) ne 0</tt> into <tt>exists([expr])</tt>
           * - <tt>count([expr]) != 0</tt> into <tt>exists([expr])</tt>
           * - <tt>0 ne count([expr])</tt> into <tt>exists([expr])</tt>
           * - <tt>0 != count([expr])</tt> into <tt>exists([expr])</tt>
           * - <tt>count([expr]) eq 0</tt> into <tt>empty([expr])</tt>
           * - <tt>count([expr]) = 0</tt> into <tt>empty([expr])</tt>
           * - <tt>0 eq count([expr])</tt> into <tt>empty([expr])</tt>
           * - <tt>0 = count([expr])</tt> into <tt>empty([expr])</tt>
           * - <tt>count([expr]) ge 1</tt> into <tt>exists([expr])</tt>
           * - <tt>count([expr]) >= 1</tt> into <tt>exists([expr])</tt>
           */
          extern OptimizationPass::List comparisonPasses;
  
          /**
           * A list of OptimizerPass instances that performs the
           * following rewrites:
           *
           * - <tt>for $var in [expr] return $var</tt> into <tt>[expr]</tt>
           */
          extern OptimizationPass::List forPasses;
  
          /**
           * A list of OptimizerPass instances that performs the
           * following rewrites:
           *
           * - <tt>if([expr of type xs:boolean]) then true() else false()</tt>
           *   into <tt>[expr of type xs:boolean]</tt>
           */
          extern OptimizationPass::List ifThenPasses;
  
          /**
           * A list of OptimizerPass instances that performs the
           * following rewrites:
           *
           * - <tt>fn:not(fn:exists([expr]))</tt> into <tt>fn:empty([expr])</tt>
           * - <tt>fn:not(fn:empty([expr]))</tt> into <tt>fn:exists([expr])</tt>
           */
          extern OptimizationPass::List notFN;
  
          /**
           * Initializes the data members in the OptimizationPasses namespace.
           *
           * This class is not supposed to be instantiated, but to be used via its init()
           * function. In fact, this class cannot be instantiated.
           *
           * @author Frans englich <frans.englich@nokia.com>
           */
          class Coordinator
          {
          public:
              /**
               * Initializes the members in the OptimizationPasses namespace.
               */
              static void init();
  
          private:
              Q_DISABLE_COPY(Coordinator)
              inline Coordinator();
          };
      }
  }
  
  QT_END_NAMESPACE
  
  #endif
  