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** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). | |
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** This file is part of the QtXmlPatterns module of the Qt Toolkit. | |
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** GNU General Public License Usage | |
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** file. Please review the following information to ensure the GNU General | |
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#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 |