Windows-4.7.4/src/xmlpatterns/expr/qgeneralcomparison.cpp - 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.
 **
 **
 **
 **
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include "qbuiltintypes_p.h"
 #include "qcommonsequencetypes_p.h"
 #include "qcommonvalues_p.h"
 #include "qebvextractor_p.h"
 #include "qitem_p.h"
 #include "qliteral_p.h"
 #include "qoptimizationpasses_p.h"
 #include "quntypedatomicconverter_p.h"
 #include "qvaluecomparison_p.h"

 #include "qgeneralcomparison_p.h"

 QT_BEGIN_NAMESPACE

 using namespace QPatternist;

 GeneralComparison::GeneralComparison(const Expression::Ptr &op1,
                                      const AtomicComparator::Operator op,
                                      const Expression::Ptr &op2,
                                      const bool isBackwardsCompat) : PairContainer(op1, op2)
                                                                    , m_operator(op)
                                                                    , m_isBackwardsCompat(isBackwardsCompat)
 {
 }

 bool GeneralComparison::generalCompare(const Item &op1,
                                        const Item &op2,
                                        const DynamicContext::Ptr &context) const
 {
     Q_ASSERT(op1);
     Q_ASSERT(op2);

     if(comparator())
         return compare(op1, op2, comparator(), m_operator);

     Expression::Ptr a1(new Literal(op1));
     Expression::Ptr a2(new Literal(op2));

     const AtomicComparator::Ptr comp(fetchGeneralComparator(a1, a2, context));
     /* The fetchGeneralComparator call may rewrite a1 and/or a2. */
     Q_ASSERT(a1);
     Q_ASSERT(a2);
     Q_ASSERT(comp);

     return compare(a1->evaluateSingleton(context),
                    a2->evaluateSingleton(context),
                    comp,
                    m_operator);
 }

 bool GeneralComparison::evaluateEBV(const DynamicContext::Ptr &context) const
 {
     const Item::Iterator::Ptr it1(m_operand1->evaluateSequence(context));
     Item item1(it1->next());

     if(!item1)
         return false;

     const Item::Iterator::Ptr it2(m_operand2->evaluateSequence(context));
     Item::List cache;
     Item item2;

     while(true)
     {
         item2 = it2->next();
         if(!item2)
             break;

         if(generalCompare(item1, item2, context))
             return true;

         cache.append(item2);
     }

     while(true)
     {
         item1 = it1->next();

         if(!item1)
             return false;

         const Item::List::const_iterator end(cache.constEnd());
         Item::List::const_iterator it(cache.constBegin());

         for(; it != end; ++it)
             if(generalCompare(item1, *it, context))
                 return true;
     }

     Q_ASSERT(false);
     return false;
 }

 Expression::Ptr GeneralComparison::compress(const StaticContext::Ptr &context)
 {
     const Expression::Ptr me(PairContainer::compress(context));

     if(me != this)
         return me;

     if(ValueComparison::isCaseInsensitiveCompare(m_operand1, m_operand2))
         useCaseInsensitiveComparator();

     return me;
 }

 Expression::Ptr GeneralComparison::typeCheck(const StaticContext::Ptr &context,
                                              const SequenceType::Ptr &reqType)
 {

     const Expression::Ptr me(PairContainer::typeCheck(context, reqType));

     const ItemType::Ptr t1(m_operand1->staticType()->itemType());
     const ItemType::Ptr t2(m_operand2->staticType()->itemType());

     if(*CommonSequenceTypes::Empty == *t1 ||
        *CommonSequenceTypes::Empty == *t2)
     {
         return wrapLiteral(CommonValues::BooleanFalse, context, this);
     }

     if(*BuiltinTypes::xsAnyAtomicType == *t1 ||
        *BuiltinTypes::xsAnyAtomicType == *t2)
         return me;

     prepareComparison(fetchGeneralComparator(m_operand1, m_operand2, context));

     if(!m_operand1->staticType()->cardinality().allowsMany() &&
        !m_operand2->staticType()->cardinality().allowsMany())
     {
         /* Rewrite to a ValueComparison whose operands uses typing rules
          * as for an general comparison(that's what's done above). */
         return rewrite(Expression::Ptr(new ValueComparison(m_operand1,
                                                            m_operator,
                                                            m_operand2))->typeCheck(context, reqType),
                        context);
     }
     else
         return me;
 }

 void GeneralComparison::updateType(ItemType::Ptr &type,
                                    const Expression::Ptr &source)
 {
     type = source->staticType()->itemType();
 }

 AtomicComparator::Ptr GeneralComparison::fetchGeneralComparator(Expression::Ptr &op1,
                                                                 Expression::Ptr &op2,
                                                                 const ReportContext::Ptr &context) const
 {
     ItemType::Ptr t1(op1->staticType()->itemType());
     ItemType::Ptr t2(op2->staticType()->itemType());

     /* a. "If one of the atomic values is an instance of xs:untypedAtomic and
      *    the other is an instance of a numeric type, then the xs:untypedAtomic
      *    value is cast to the type xs:double." */
     if(BuiltinTypes::numeric->xdtTypeMatches(t1) &&
        BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2))
     {
         op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble));

         /* The types might have changed, reload. */
         updateType(t2, op2);
     }
     else if(BuiltinTypes::numeric->xdtTypeMatches(t2) &&
             BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1))
     {
         op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble));

         /* The types might have changed, reload. */
         updateType(t1, op1);
     }
     /* "If XPath 1.0 compatibility mode is true, a general comparison is
      *  evaluated by applying the following rules, in order:
      *  1. If either operand is a single atomic value that is an instance of
      *  xs:boolean, then the other operand is converted to xs:boolean by taking
      *  its effective boolean value."
      *
      * Notably, it's not conversion to boolean, it is EBV extraction.
      */
     else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(t1))
     {
         op2 = Expression::Ptr(new EBVExtractor(op2));
         updateType(t2, op2);
     }
     else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(t2))
     {
         op1 = Expression::Ptr(new EBVExtractor(op1));
         updateType(t1, op1);
     }
     /* b. "If one of the atomic values is an instance of xs:untypedAtomic and
      *    the other is an instance of xs:untypedAtomic or xs:string, then the
      *    xs:untypedAtomic value (or values) is (are) cast to the type xs:string."
      *
      * c. "If one of the atomic values is an instance of xs:untypedAtomic and the
      *    other is not an instance of xs:string, xs:untypedAtomic, or any numeric
      *    type, then the xs:untypedAtomic value is cast to the dynamic type of the
      *    other value." */
     else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1) &&
             !BuiltinTypes::xsString->xdtTypeMatches(t2) &&
             !BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2) &&
             !BuiltinTypes::xsAnyURI->xdtTypeMatches(t2))
     {
         op1 = Expression::Ptr(new UntypedAtomicConverter(op1, t2));
         updateType(t1, op1);
     }
     else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2) &&
             !BuiltinTypes::xsString->xdtTypeMatches(t1) &&
             !BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1) &&
             !BuiltinTypes::xsAnyURI->xdtTypeMatches(t1))
     {
         op2 = Expression::Ptr(new UntypedAtomicConverter(op2, t1));
         updateType(t2, op2);
     }

     /* d. "After performing the conversions described above, the atomic
      *     values are compared using one of the value comparison operators
      *     eq, ne, lt, le, gt, or ge, depending on whether the general comparison
      *     operator was =, !=, <, <=, >, or >=. The values have the required
      *     magnitude relationship if and only if the result of this value comparison
      *     is true." */

     return fetchComparator(t1, t2, context);
 }

 OptimizationPass::List GeneralComparison::optimizationPasses() const
 {
     Q_ASSERT(!OptimizationPasses::comparisonPasses.isEmpty());
     return OptimizationPasses::comparisonPasses;
 }

 SequenceType::List GeneralComparison::expectedOperandTypes() const
 {
     SequenceType::List result;
     result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
     result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
     return result;
 }

 SequenceType::Ptr GeneralComparison::staticType() const
 {
     return CommonSequenceTypes::ExactlyOneBoolean;
 }

 ExpressionVisitorResult::Ptr GeneralComparison::accept(const ExpressionVisitor::Ptr &visitor) const
 {
     return visitor->visit(this);
 }

 Expression::ID GeneralComparison::id() const
 {
     return IDGeneralComparison;
 }

 QT_END_NAMESPACE
	/****************************************************************************
	**
	** 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.
	**
	**
	**
	**
	**
	** $QT_END_LICENSE$
	**
	****************************************************************************/

	#include "qbuiltintypes_p.h"
	#include "qcommonsequencetypes_p.h"
	#include "qcommonvalues_p.h"
	#include "qebvextractor_p.h"
	#include "qitem_p.h"
	#include "qliteral_p.h"
	#include "qoptimizationpasses_p.h"
	#include "quntypedatomicconverter_p.h"
	#include "qvaluecomparison_p.h"

	#include "qgeneralcomparison_p.h"

	QT_BEGIN_NAMESPACE

	using namespace QPatternist;

	GeneralComparison::GeneralComparison(const Expression::Ptr &op1,
	const AtomicComparator::Operator op,
	const Expression::Ptr &op2,
	const bool isBackwardsCompat) : PairContainer(op1, op2)
	, m_operator(op)
	, m_isBackwardsCompat(isBackwardsCompat)
	{
	}

	bool GeneralComparison::generalCompare(const Item &op1,
	const Item &op2,
	const DynamicContext::Ptr &context) const
	{
	Q_ASSERT(op1);
	Q_ASSERT(op2);

	if(comparator())
	return compare(op1, op2, comparator(), m_operator);

	Expression::Ptr a1(new Literal(op1));
	Expression::Ptr a2(new Literal(op2));

	const AtomicComparator::Ptr comp(fetchGeneralComparator(a1, a2, context));
	/* The fetchGeneralComparator call may rewrite a1 and/or a2. */
	Q_ASSERT(a1);
	Q_ASSERT(a2);
	Q_ASSERT(comp);

	return compare(a1->evaluateSingleton(context),
	a2->evaluateSingleton(context),
	comp,
	m_operator);
	}

	bool GeneralComparison::evaluateEBV(const DynamicContext::Ptr &context) const
	{
	const Item::Iterator::Ptr it1(m_operand1->evaluateSequence(context));
	Item item1(it1->next());

	if(!item1)
	return false;

	const Item::Iterator::Ptr it2(m_operand2->evaluateSequence(context));
	Item::List cache;
	Item item2;

	while(true)
	{
	item2 = it2->next();
	if(!item2)
	break;

	if(generalCompare(item1, item2, context))
	return true;

	cache.append(item2);
	}

	while(true)
	{
	item1 = it1->next();

	if(!item1)
	return false;

	const Item::List::const_iterator end(cache.constEnd());
	Item::List::const_iterator it(cache.constBegin());

	for(; it != end; ++it)
	if(generalCompare(item1, *it, context))
	return true;
	}

	Q_ASSERT(false);
	return false;
	}

	Expression::Ptr GeneralComparison::compress(const StaticContext::Ptr &context)
	{
	const Expression::Ptr me(PairContainer::compress(context));

	if(me != this)
	return me;

	if(ValueComparison::isCaseInsensitiveCompare(m_operand1, m_operand2))
	useCaseInsensitiveComparator();

	return me;
	}

	Expression::Ptr GeneralComparison::typeCheck(const StaticContext::Ptr &context,
	const SequenceType::Ptr &reqType)
	{

	const Expression::Ptr me(PairContainer::typeCheck(context, reqType));

	const ItemType::Ptr t1(m_operand1->staticType()->itemType());
	const ItemType::Ptr t2(m_operand2->staticType()->itemType());

	if(CommonSequenceTypes::Empty == t1 \|\|
	CommonSequenceTypes::Empty == t2)
	{
	return wrapLiteral(CommonValues::BooleanFalse, context, this);
	}

	if(BuiltinTypes::xsAnyAtomicType == t1 \|\|
	BuiltinTypes::xsAnyAtomicType == t2)
	return me;

	prepareComparison(fetchGeneralComparator(m_operand1, m_operand2, context));

	if(!m_operand1->staticType()->cardinality().allowsMany() &&
	!m_operand2->staticType()->cardinality().allowsMany())
	{
	/* Rewrite to a ValueComparison whose operands uses typing rules
	* as for an general comparison(that's what's done above). */
	return rewrite(Expression::Ptr(new ValueComparison(m_operand1,
	m_operator,
	m_operand2))->typeCheck(context, reqType),
	context);
	}
	else
	return me;
	}

	void GeneralComparison::updateType(ItemType::Ptr &type,
	const Expression::Ptr &source)
	{
	type = source->staticType()->itemType();
	}

	AtomicComparator::Ptr GeneralComparison::fetchGeneralComparator(Expression::Ptr &op1,
	Expression::Ptr &op2,
	const ReportContext::Ptr &context) const
	{
	ItemType::Ptr t1(op1->staticType()->itemType());
	ItemType::Ptr t2(op2->staticType()->itemType());

	/* a. "If one of the atomic values is an instance of xs:untypedAtomic and
	* the other is an instance of a numeric type, then the xs:untypedAtomic
	* value is cast to the type xs:double." */
	if(BuiltinTypes::numeric->xdtTypeMatches(t1) &&
	BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2))
	{
	op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble));

	/* The types might have changed, reload. */
	updateType(t2, op2);
	}
	else if(BuiltinTypes::numeric->xdtTypeMatches(t2) &&
	BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1))
	{
	op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble));

	/* The types might have changed, reload. */
	updateType(t1, op1);
	}
	/* "If XPath 1.0 compatibility mode is true, a general comparison is
	* evaluated by applying the following rules, in order:
	* 1. If either operand is a single atomic value that is an instance of
	* xs:boolean, then the other operand is converted to xs:boolean by taking
	* its effective boolean value."
	*
	* Notably, it's not conversion to boolean, it is EBV extraction.
	*/
	else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(t1))
	{
	op2 = Expression::Ptr(new EBVExtractor(op2));
	updateType(t2, op2);
	}
	else if(m_isBackwardsCompat && BuiltinTypes::xsBoolean->xdtTypeMatches(t2))
	{
	op1 = Expression::Ptr(new EBVExtractor(op1));
	updateType(t1, op1);
	}
	/* b. "If one of the atomic values is an instance of xs:untypedAtomic and
	* the other is an instance of xs:untypedAtomic or xs:string, then the
	* xs:untypedAtomic value (or values) is (are) cast to the type xs:string."
	*
	* c. "If one of the atomic values is an instance of xs:untypedAtomic and the
	* other is not an instance of xs:string, xs:untypedAtomic, or any numeric
	* type, then the xs:untypedAtomic value is cast to the dynamic type of the
	* other value." */
	else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1) &&
	!BuiltinTypes::xsString->xdtTypeMatches(t2) &&
	!BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2) &&
	!BuiltinTypes::xsAnyURI->xdtTypeMatches(t2))
	{
	op1 = Expression::Ptr(new UntypedAtomicConverter(op1, t2));
	updateType(t1, op1);
	}
	else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2) &&
	!BuiltinTypes::xsString->xdtTypeMatches(t1) &&
	!BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1) &&
	!BuiltinTypes::xsAnyURI->xdtTypeMatches(t1))
	{
	op2 = Expression::Ptr(new UntypedAtomicConverter(op2, t1));
	updateType(t2, op2);
	}

	/* d. "After performing the conversions described above, the atomic
	* values are compared using one of the value comparison operators
	* eq, ne, lt, le, gt, or ge, depending on whether the general comparison
	* operator was =, !=, <, <=, >, or >=. The values have the required
	* magnitude relationship if and only if the result of this value comparison
	* is true." */

	return fetchComparator(t1, t2, context);
	}

	OptimizationPass::List GeneralComparison::optimizationPasses() const
	{
	Q_ASSERT(!OptimizationPasses::comparisonPasses.isEmpty());
	return OptimizationPasses::comparisonPasses;
	}

	SequenceType::List GeneralComparison::expectedOperandTypes() const
	{
	SequenceType::List result;
	result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
	result.append(CommonSequenceTypes::ZeroOrMoreAtomicTypes);
	return result;
	}

	SequenceType::Ptr GeneralComparison::staticType() const
	{
	return CommonSequenceTypes::ExactlyOneBoolean;
	}

	ExpressionVisitorResult::Ptr GeneralComparison::accept(const ExpressionVisitor::Ptr &visitor) const
	{
	return visitor->visit(this);
	}

	Expression::ID GeneralComparison::id() const
	{
	return IDGeneralComparison;
	}

	QT_END_NAMESPACE