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3 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
4 ** Contact: http://www.qt-project.org/
6 ** This file is part of the QtXmlPatterns module of the Qt Toolkit.
8 ** $QT_BEGIN_LICENSE:LGPL$
9 ** GNU Lesser General Public License Usage
10 ** This file may be used under the terms of the GNU Lesser General Public
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21 ** GNU General Public License Usage
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40 ****************************************************************************/
42 #include "qcommonsequencetypes_p.h"
43 #include "qexceptiterator_p.h"
44 #include "qgenericsequencetype_p.h"
45 #include "qintersectiterator_p.h"
46 #include "qitemmappingiterator_p.h"
47 #include "qnodesort_p.h"
48 #include "qunioniterator_p.h"
50 #include "qcombinenodes_p.h"
54 using namespace QPatternist;
56 CombineNodes::CombineNodes(const Expression::Ptr &operand1,
58 const Expression::Ptr &operand2) : PairContainer(operand1, operand2),
61 Q_ASSERT(op == Union ||
66 Item::Iterator::Ptr CombineNodes::evaluateSequence(const DynamicContext::Ptr &context) const
68 const Item::Iterator::Ptr op1(m_operand1->evaluateSequence(context));
69 const Item::Iterator::Ptr op2(m_operand2->evaluateSequence(context));
74 return Item::Iterator::Ptr(new IntersectIterator(op1, op2));
76 return Item::Iterator::Ptr(new ExceptIterator(op1, op2));
79 Q_ASSERT(m_operator == Union);
80 return Item::Iterator::Ptr(new UnionIterator(op1, op2));
85 Item CombineNodes::evaluateSingleton(const DynamicContext::Ptr &context) const
87 return evaluateSequence(context)->next();
90 Expression::Ptr CombineNodes::typeCheck(const StaticContext::Ptr &context,
91 const SequenceType::Ptr &reqType)
94 const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
96 m_operand1 = NodeSortExpression::wrapAround(m_operand1, context);
97 m_operand2 = NodeSortExpression::wrapAround(m_operand2, context);
102 bool CombineNodes::evaluateEBV(const DynamicContext::Ptr &context) const
104 /* If it's the union operator, we can possibly avoid
105 * evaluating the second operand. */
107 if(m_operator == Union)
109 return m_operand1->evaluateEBV(context) ||
110 m_operand2->evaluateEBV(context);
113 return PairContainer::evaluateEBV(context);
116 QString CombineNodes::displayName(const Operator op)
121 return QLatin1String("intersect");
123 return QLatin1String("except");
126 Q_ASSERT(op == Union);
127 return QLatin1String("union");
132 SequenceType::Ptr CombineNodes::staticType() const
134 const SequenceType::Ptr t1(m_operand1->staticType());
135 const SequenceType::Ptr t2(m_operand2->staticType());
139 /* Optimization: the cardinality can be better inferred for
140 * Intersect and Except, although it's not trivial code. */
141 if(m_operator == Union)
142 card = t1->cardinality() | t2->cardinality();
144 card = Cardinality::zeroOrMore();
146 return makeGenericSequenceType(t1->itemType() | t2->itemType(), card);
149 SequenceType::List CombineNodes::expectedOperandTypes() const
151 SequenceType::List result;
152 result.append(CommonSequenceTypes::ZeroOrMoreNodes);
153 result.append(CommonSequenceTypes::ZeroOrMoreNodes);
157 CombineNodes::Operator CombineNodes::operatorID() const
162 ExpressionVisitorResult::Ptr CombineNodes::accept(const ExpressionVisitor::Ptr &visitor) const
164 return visitor->visit(this);
167 Expression::ID CombineNodes::id() const
169 return IDCombineNodes;