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Diffstat (limited to 'src/xmlpatterns/expr/qgeneralcomparison.cpp')
| -rw-r--r-- | src/xmlpatterns/expr/qgeneralcomparison.cpp | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qgeneralcomparison.cpp b/src/xmlpatterns/expr/qgeneralcomparison.cpp new file mode 100644 index 0000000000..b564c84ef0 --- /dev/null +++ b/src/xmlpatterns/expr/qgeneralcomparison.cpp @@ -0,0 +1,297 @@ +/**************************************************************************** +** +** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies). +** Contact: Qt Software Information (qt-info@nokia.com) +** +** This file is part of the QtXmlPatterns module of the Qt Toolkit. +** +** $QT_BEGIN_LICENSE:LGPL$ +** No Commercial Usage +** This file contains pre-release code and may not be distributed. +** You may use this file in accordance with the terms and conditions +** contained in the either Technology Preview License Agreement or the +** Beta Release License Agreement. +** +** GNU Lesser General Public License Usage +** Alternatively, 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 1.0, 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. +** +** If you are unsure which license is appropriate for your use, please +** contact the sales department at qt-sales@nokia.com. +** $QT_END_LICENSE$ +** +****************************************************************************/ + +#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 |