Windows-4.7.4/src/xmlpatterns/expr/qoptimizerframework_p.h - platform/external/qt - Git at Google

 /****************************************************************************
 **
 ** 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_OptimizerFramework_H
 #define Patternist_OptimizerFramework_H

 #include <QSharedData>

 #include "qexpression_p.h"

 QT_BEGIN_HEADER

 QT_BEGIN_NAMESPACE

 namespace QPatternist
 {
     /**
      * @short A factory for creating Expression instances.
      *
      * ExpressionIdentifier is one of the building block of Patternist's
      * optimizer framework. An ExpressionIdentifier sub-class has
      * the responsibility of creating the Expression that should be
      * the result of the optimization.
      *
      * This class and sub-classes are never used on their own,
      * but in cooperation with OptimizationPass.
      *
      * @author Frans englich <frans.englich@nokia.com>
      * @ingroup Patternist_expressions
      */
     class ExpressionCreator : public QSharedData
     {
     public:
         typedef QExplicitlySharedDataPointer<ExpressionCreator> Ptr;

         /**
          * For some reason this constructor cannot be synthesized.
          */
         inline ExpressionCreator()
         {
         }

         virtual ~ExpressionCreator();
         /**
          * Creates an expression that has @p operands as operands.
          *
          * The Expression that is returned is guaranteed, by the caller,
          * to get a treatment identical to if the expression was created
          * in an ordinary compilation(via the parser, and so forth). That is,
          * Expression::typeCheck() and Expression::compress() stages will be
          * carried out on the returned expression.
          *
          * @returns an Expression::Ptr that never is non @c null, valid pointer
          */
         virtual Expression::Ptr create(const Expression::List &operands,
                                        const StaticContext::Ptr &context,
                                        const SourceLocationReflection *const) const = 0;

     private:
         Q_DISABLE_COPY(ExpressionCreator)
     };

     /**
      * @short Abstract base class for all classes that identify Expressions
      * based on some criteria.
      *
      * ExpressionIdentifier is one of the building block of Patternist's
      * optimizer framework. An ExpressionIdentifier sub-class has
      * the responsibility of determining whether a particular Expression
      * is the one an OptimizationPass should apply for.
      *
      * This class and sub-classes are never used on their own,
      * but in cooperation with OptimizationPass.
      *
      * @author Frans englich <frans.englich@nokia.com>
      * @ingroup Patternist_expressions
      */
     class ExpressionIdentifier : public QSharedData
     {
     public:
         typedef QExplicitlySharedDataPointer<ExpressionIdentifier> Ptr;
         typedef QList<ExpressionIdentifier::Ptr> List;

         /**
          * For some reason this constructor cannot be synthesized.
          */
         inline ExpressionIdentifier()
         {
         }

         virtual ~ExpressionIdentifier();
         /**
          * @param expr the Expression to be tested. This is guranteed
          * to always be a non @c null, valid pointer.
          *
          * @returns @c true if @p expr matches as according to this ExpressionIdentifier,
          * otherwise @c false.
          */
         virtual bool matches(const Expression::Ptr &expr) const = 0;

     private:
         Q_DISABLE_COPY(ExpressionIdentifier)
     };

     /**
      * @short Describes how a particular optimization pass should be carried out.
      *
      * OptimizationPass is essentially a declaration, which describes
      * how an optimization pass in the form of an AST rewrite should be done,
      * by describing what that should be rewritten into what how.
      *
      * Each OptimizationPass is applied to a "start" Expression. The Expression
      * that qualifies as a start Expression for the OptimizationPass in question is
      * determined by startIdentifier; if its ExpressionIdentifier::matches() function
      * returns @c true, the optimizer continues to apply this OptimizationPass.
      *
      * After a start Expression has been found, it is verified if the operands matches
      * as well by applying the ExpressionIdentifiers in operandIdentifiers to the
      * start Expression's operands. Similarly, if the operands matches what
      * operandIdentifiers requires, the optimizer continues to apply this OptimizationPass.
      *
      * At this stage, it has been concluded that the OptimizationPass validly applies, and
      * what now remains is to carry out the actual rewrite. The Expression rewritten
      * to is the one returned by ExpressionCreator::create(), when invoked via the resultCreator
      * variable.
      *
      * How these components, startIdentifier, operandIdentifiers, sourceExpression,
      * and resultCreator interacts with one another is described in more detail
      * in the member documentation as well as the classes they are instances of.
      *
      * @author Frans englich <frans.englich@nokia.com>
      * @ingroup Patternist_expressions
      */
     class OptimizationPass : public QSharedData
     {
     public:
         typedef QExplicitlySharedDataPointer<OptimizationPass> Ptr;
         typedef QList<OptimizationPass::Ptr> List;

         enum OperandsMatchMethod
         {
             /**
              * All operands must match in the same order the ExpressionMarkers do.
              */
             Sequential = 1,

             /**
              * Matches if all operands are matched, regardless of their order. This is
              * useful when an OptimizationPass is matching an Expression that has two operands
              * and that both of them can appear on the left or right hand as long as it is those
              * two.
              *
              * This comparison method only works when two operands
              * needs to be matched.
              */
             AnyOrder
         };

         /**
          * An ExpressionMarker identifies an operand Expression relatively
          * the start Expression by that each integer identifies a step
          * in a descending AST walk. For example an ExpressionMarker with
          * only one entry that is 0(zero), identifies the first operand of the
          * start Expression. An ExpressionMarker containing 1, 2 in that order
          * identifies the third operand of the second operand of the start Expression.
          */
         typedef QList<qint8> ExpressionMarker;

         /**
          * Creates an OptimizationPass and sets its public variables
          * to the corresponding values passed in this constructor.
          */
         OptimizationPass(const ExpressionIdentifier::Ptr &startID,
                          const ExpressionIdentifier::List &operandIDs,
                          const ExpressionMarker &sourceExpr,
                          const ExpressionCreator::Ptr &resultCtor = ExpressionCreator::Ptr(),
                          const OperandsMatchMethod matchMethod = Sequential);

         /**
          * The ExpressionIdentifier that must the Expression this OptimizationPass concerns.
          *
          * If this variable is @c null, it means that the start Expression does
          * not have to match any particular ExpressionIdentifier, but is fine as is.
          *
          * One might wonder what the purpose of this startIdentifier is, considering
          * that what start Expression an OptimizationPass can at all apply to is
          * naturally determined by what Expression::optimizationPasses() re-implementation that
          * returns this OptimizationPass. The reason is that in some cases an OptimizationPass
          * nevertheless doesn't apply. For example, optimizations applying to a ValueComparison
          * might depend on what operator that is in use.
          *
          * May be @c null or point to an ExpressionIdentifier.
          */
         const ExpressionIdentifier::Ptr startIdentifier;

         /**
          * In order for an OptimizationPass to apply, the start Expression's
          * operands must be matched with this list of ExpressionIdentifier instances.
          * The first ExpressionIdentifier is applied to the first operand, the second
          * ExpressionIdentifier to the second operand, and so forth until all operands
          * have been iterated.
          *
          * Entries in this list may be @c null, and those signals that the corresponding
          * operand is not constrained. For example, if the third ExpressionIdentifier in
          * the list is @c null, it signals that the third operand may be anykind of expression.
          *
          * May be empty or contain an arbitrary amount of objects or @c null pointers.
          */
         const ExpressionIdentifier::List operandIdentifiers;

         /**
          * Identifies the expression that should be part of the new expression
          * that this OptimizationPass rewrites to. If this list is empty, it
          * means that the result is not derived from the existing tree, and
          * that resultCreator will exclusively be used for creating the result
          * Expression.
          *
          * How the ExpressionMarker identifies an Expression is document in
          * its documentation.
          *
          * May be empty.
          */
         const ExpressionMarker sourceExpression;

         /**
          * This is the ExpressionCreator that will be used to create the
          * Expression which is the result. ExpressionCreator::create()
          * will be passed as operands the Expression that sourceExpression
          * specify, if any.
          *
          * If this variable is @c null, the result Expression will be the one
          * sourceExpression identifies.
          */
         const ExpressionCreator::Ptr resultCreator;

         const OperandsMatchMethod operandsMatchMethod;
     private:
         Q_DISABLE_COPY(OptimizationPass)
     };
 }

 QT_END_NAMESPACE

 QT_END_HEADER

 #endif
	/****************************************************************************
	**
	** 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_OptimizerFramework_H
	#define Patternist_OptimizerFramework_H

	#include <QSharedData>

	#include "qexpression_p.h"

	QT_BEGIN_HEADER

	QT_BEGIN_NAMESPACE

	namespace QPatternist
	{
	/**
	* @short A factory for creating Expression instances.
	*
	* ExpressionIdentifier is one of the building block of Patternist's
	* optimizer framework. An ExpressionIdentifier sub-class has
	* the responsibility of creating the Expression that should be
	* the result of the optimization.
	*
	* This class and sub-classes are never used on their own,
	* but in cooperation with OptimizationPass.
	*
	* @author Frans englich <frans.englich@nokia.com>
	* @ingroup Patternist_expressions
	*/
	class ExpressionCreator : public QSharedData
	{
	public:
	typedef QExplicitlySharedDataPointer<ExpressionCreator> Ptr;

	/**
	* For some reason this constructor cannot be synthesized.
	*/
	inline ExpressionCreator()
	{
	}

	virtual ~ExpressionCreator();
	/**
	* Creates an expression that has @p operands as operands.
	*
	* The Expression that is returned is guaranteed, by the caller,
	* to get a treatment identical to if the expression was created
	* in an ordinary compilation(via the parser, and so forth). That is,
	* Expression::typeCheck() and Expression::compress() stages will be
	* carried out on the returned expression.
	*
	* @returns an Expression::Ptr that never is non @c null, valid pointer
	*/
	virtual Expression::Ptr create(const Expression::List &operands,
	const StaticContext::Ptr &context,
	const SourceLocationReflection *const) const = 0;

	private:
	Q_DISABLE_COPY(ExpressionCreator)
	};

	/**
	* @short Abstract base class for all classes that identify Expressions
	* based on some criteria.
	*
	* ExpressionIdentifier is one of the building block of Patternist's
	* optimizer framework. An ExpressionIdentifier sub-class has
	* the responsibility of determining whether a particular Expression
	* is the one an OptimizationPass should apply for.
	*
	* This class and sub-classes are never used on their own,
	* but in cooperation with OptimizationPass.
	*
	* @author Frans englich <frans.englich@nokia.com>
	* @ingroup Patternist_expressions
	*/
	class ExpressionIdentifier : public QSharedData
	{
	public:
	typedef QExplicitlySharedDataPointer<ExpressionIdentifier> Ptr;
	typedef QList<ExpressionIdentifier::Ptr> List;

	/**
	* For some reason this constructor cannot be synthesized.
	*/
	inline ExpressionIdentifier()
	{
	}

	virtual ~ExpressionIdentifier();
	/**
	* @param expr the Expression to be tested. This is guranteed
	* to always be a non @c null, valid pointer.
	*
	* @returns @c true if @p expr matches as according to this ExpressionIdentifier,
	* otherwise @c false.
	*/
	virtual bool matches(const Expression::Ptr &expr) const = 0;

	private:
	Q_DISABLE_COPY(ExpressionIdentifier)
	};

	/**
	* @short Describes how a particular optimization pass should be carried out.
	*
	* OptimizationPass is essentially a declaration, which describes
	* how an optimization pass in the form of an AST rewrite should be done,
	* by describing what that should be rewritten into what how.
	*
	* Each OptimizationPass is applied to a "start" Expression. The Expression
	* that qualifies as a start Expression for the OptimizationPass in question is
	* determined by startIdentifier; if its ExpressionIdentifier::matches() function
	* returns @c true, the optimizer continues to apply this OptimizationPass.
	*
	* After a start Expression has been found, it is verified if the operands matches
	* as well by applying the ExpressionIdentifiers in operandIdentifiers to the
	* start Expression's operands. Similarly, if the operands matches what
	* operandIdentifiers requires, the optimizer continues to apply this OptimizationPass.
	*
	* At this stage, it has been concluded that the OptimizationPass validly applies, and
	* what now remains is to carry out the actual rewrite. The Expression rewritten
	* to is the one returned by ExpressionCreator::create(), when invoked via the resultCreator
	* variable.
	*
	* How these components, startIdentifier, operandIdentifiers, sourceExpression,
	* and resultCreator interacts with one another is described in more detail
	* in the member documentation as well as the classes they are instances of.
	*
	* @author Frans englich <frans.englich@nokia.com>
	* @ingroup Patternist_expressions
	*/
	class OptimizationPass : public QSharedData
	{
	public:
	typedef QExplicitlySharedDataPointer<OptimizationPass> Ptr;
	typedef QList<OptimizationPass::Ptr> List;

	enum OperandsMatchMethod
	{
	/**
	* All operands must match in the same order the ExpressionMarkers do.
	*/
	Sequential = 1,

	/**
	* Matches if all operands are matched, regardless of their order. This is
	* useful when an OptimizationPass is matching an Expression that has two operands
	* and that both of them can appear on the left or right hand as long as it is those
	* two.
	*
	* This comparison method only works when two operands
	* needs to be matched.
	*/
	AnyOrder
	};

	/**
	* An ExpressionMarker identifies an operand Expression relatively
	* the start Expression by that each integer identifies a step
	* in a descending AST walk. For example an ExpressionMarker with
	* only one entry that is 0(zero), identifies the first operand of the
	* start Expression. An ExpressionMarker containing 1, 2 in that order
	* identifies the third operand of the second operand of the start Expression.
	*/
	typedef QList<qint8> ExpressionMarker;

	/**
	* Creates an OptimizationPass and sets its public variables
	* to the corresponding values passed in this constructor.
	*/
	OptimizationPass(const ExpressionIdentifier::Ptr &startID,
	const ExpressionIdentifier::List &operandIDs,
	const ExpressionMarker &sourceExpr,
	const ExpressionCreator::Ptr &resultCtor = ExpressionCreator::Ptr(),
	const OperandsMatchMethod matchMethod = Sequential);

	/**
	* The ExpressionIdentifier that must the Expression this OptimizationPass concerns.
	*
	* If this variable is @c null, it means that the start Expression does
	* not have to match any particular ExpressionIdentifier, but is fine as is.
	*
	* One might wonder what the purpose of this startIdentifier is, considering
	* that what start Expression an OptimizationPass can at all apply to is
	* naturally determined by what Expression::optimizationPasses() re-implementation that
	* returns this OptimizationPass. The reason is that in some cases an OptimizationPass
	* nevertheless doesn't apply. For example, optimizations applying to a ValueComparison
	* might depend on what operator that is in use.
	*
	* May be @c null or point to an ExpressionIdentifier.
	*/
	const ExpressionIdentifier::Ptr startIdentifier;

	/**
	* In order for an OptimizationPass to apply, the start Expression's
	* operands must be matched with this list of ExpressionIdentifier instances.
	* The first ExpressionIdentifier is applied to the first operand, the second
	* ExpressionIdentifier to the second operand, and so forth until all operands
	* have been iterated.
	*
	* Entries in this list may be @c null, and those signals that the corresponding
	* operand is not constrained. For example, if the third ExpressionIdentifier in
	* the list is @c null, it signals that the third operand may be anykind of expression.
	*
	* May be empty or contain an arbitrary amount of objects or @c null pointers.
	*/
	const ExpressionIdentifier::List operandIdentifiers;

	/**
	* Identifies the expression that should be part of the new expression
	* that this OptimizationPass rewrites to. If this list is empty, it
	* means that the result is not derived from the existing tree, and
	* that resultCreator will exclusively be used for creating the result
	* Expression.
	*
	* How the ExpressionMarker identifies an Expression is document in
	* its documentation.
	*
	* May be empty.
	*/
	const ExpressionMarker sourceExpression;

	/**
	* This is the ExpressionCreator that will be used to create the
	* Expression which is the result. ExpressionCreator::create()
	* will be passed as operands the Expression that sourceExpression
	* specify, if any.
	*
	* If this variable is @c null, the result Expression will be the one
	* sourceExpression identifies.
	*/
	const ExpressionCreator::Ptr resultCreator;

	const OperandsMatchMethod operandsMatchMethod;
	private:
	Q_DISABLE_COPY(OptimizationPass)
	};
	}

	QT_END_NAMESPACE

	QT_END_HEADER

	#endif