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Diffstat (limited to 'src/xmlpatterns/expr/qcombinenodes.cpp')
-rw-r--r-- | src/xmlpatterns/expr/qcombinenodes.cpp | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qcombinenodes.cpp b/src/xmlpatterns/expr/qcombinenodes.cpp new file mode 100644 index 0000000..c953322 --- /dev/null +++ b/src/xmlpatterns/expr/qcombinenodes.cpp @@ -0,0 +1,172 @@ +/**************************************************************************** +** +** 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 "qcommonsequencetypes_p.h" +#include "qexceptiterator_p.h" +#include "qgenericsequencetype_p.h" +#include "qintersectiterator_p.h" +#include "qitemmappingiterator_p.h" +#include "qnodesort_p.h" +#include "qunioniterator_p.h" + +#include "qcombinenodes_p.h" + +QT_BEGIN_NAMESPACE + +using namespace QPatternist; + +CombineNodes::CombineNodes(const Expression::Ptr &operand1, + const Operator op, + const Expression::Ptr &operand2) : PairContainer(operand1, operand2), + m_operator(op) +{ + Q_ASSERT(op == Union || + op == Except || + op == Intersect); +} + +Item::Iterator::Ptr CombineNodes::evaluateSequence(const DynamicContext::Ptr &context) const +{ + const Item::Iterator::Ptr op1(m_operand1->evaluateSequence(context)); + const Item::Iterator::Ptr op2(m_operand2->evaluateSequence(context)); + + switch(m_operator) + { + case Intersect: + return Item::Iterator::Ptr(new IntersectIterator(op1, op2)); + case Except: + return Item::Iterator::Ptr(new ExceptIterator(op1, op2)); + default: + { + Q_ASSERT(m_operator == Union); + return Item::Iterator::Ptr(new UnionIterator(op1, op2)); + } + } +} + +Item CombineNodes::evaluateSingleton(const DynamicContext::Ptr &context) const +{ + return evaluateSequence(context)->next(); +} + +Expression::Ptr CombineNodes::typeCheck(const StaticContext::Ptr &context, + const SequenceType::Ptr &reqType) +{ + + const Expression::Ptr me(PairContainer::typeCheck(context, reqType)); + + m_operand1 = NodeSortExpression::wrapAround(m_operand1, context); + m_operand2 = NodeSortExpression::wrapAround(m_operand2, context); + + return me; +} + +bool CombineNodes::evaluateEBV(const DynamicContext::Ptr &context) const +{ + /* If it's the union operator, we can possibly avoid + * evaluating the second operand. */ + + if(m_operator == Union) + { + return m_operand1->evaluateEBV(context) || + m_operand2->evaluateEBV(context); + } + else + return PairContainer::evaluateEBV(context); +} + +QString CombineNodes::displayName(const Operator op) +{ + switch(op) + { + case Intersect: + return QLatin1String("intersect"); + case Except: + return QLatin1String("except"); + default: + { + Q_ASSERT(op == Union); + return QLatin1String("union"); + } + } +} + +SequenceType::Ptr CombineNodes::staticType() const +{ + const SequenceType::Ptr t1(m_operand1->staticType()); + const SequenceType::Ptr t2(m_operand2->staticType()); + + Cardinality card; + + /* Optimization: the cardinality can be better inferred for + * Intersect and Except, although it's not trivial code. */ + if(m_operator == Union) + card = t1->cardinality() | t2->cardinality(); + else /* Except. */ + card = Cardinality::zeroOrMore(); + + return makeGenericSequenceType(t1->itemType() | t2->itemType(), card); +} + +SequenceType::List CombineNodes::expectedOperandTypes() const +{ + SequenceType::List result; + result.append(CommonSequenceTypes::ZeroOrMoreNodes); + result.append(CommonSequenceTypes::ZeroOrMoreNodes); + return result; +} + +CombineNodes::Operator CombineNodes::operatorID() const +{ + return m_operator; +} + +ExpressionVisitorResult::Ptr CombineNodes::accept(const ExpressionVisitor::Ptr &visitor) const +{ + return visitor->visit(this); +} + +Expression::ID CombineNodes::id() const +{ + return IDCombineNodes; +} + +QT_END_NAMESPACE |