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Diffstat (limited to 'src/xmlpatterns/expr/qnodecomparison.cpp')
| -rw-r--r-- | src/xmlpatterns/expr/qnodecomparison.cpp | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/src/xmlpatterns/expr/qnodecomparison.cpp b/src/xmlpatterns/expr/qnodecomparison.cpp new file mode 100644 index 0000000..2b70bf9 --- /dev/null +++ b/src/xmlpatterns/expr/qnodecomparison.cpp @@ -0,0 +1,184 @@ +/**************************************************************************** +** +** 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 "qcommonvalues_p.h" +#include "qemptysequence_p.h" +#include "qinteger_p.h" +#include "qschemanumeric_p.h" +#include "qrangeiterator_p.h" + +#include "qnodecomparison_p.h" + +QT_BEGIN_NAMESPACE + +using namespace QPatternist; + +NodeComparison::NodeComparison(const Expression::Ptr &operand1, + const QXmlNodeModelIndex::DocumentOrder op, + const Expression::Ptr &operand2) + : PairContainer(operand1, operand2) + , m_op(op) +{ + Q_ASSERT(op == QXmlNodeModelIndex::Precedes || + op == QXmlNodeModelIndex::Follows || + op == QXmlNodeModelIndex::Is); +} + +Item NodeComparison::evaluateSingleton(const DynamicContext::Ptr &context) const +{ + switch(evaluate(context)) + { + case True: + return CommonValues::BooleanTrue; + case False: + return CommonValues::BooleanFalse; + default: + return Item(); + } +} + +bool NodeComparison::evaluateEBV(const DynamicContext::Ptr &context) const +{ + switch(evaluate(context)) + { + case True: + return true; + default: + /* We include the empty sequence here. */ + return false; + } +} + +NodeComparison::Result NodeComparison::evaluate(const DynamicContext::Ptr &context) const +{ + const Item op1(m_operand1->evaluateSingleton(context)); + if(!op1) + return Empty; + + const Item op2(m_operand2->evaluateSingleton(context)); + if(!op2) + return Empty; + + /* We just returns an arbitrary value, since there's no order defined for nodes from different + * models, except for that the return value must be stable. */ + if(op1.asNode().model() != op2.asNode().model()) + return False; + + switch(m_op) + { + case QXmlNodeModelIndex::Is: + return op1.asNode().is(op2.asNode()) ? True : False; + case QXmlNodeModelIndex::Precedes: + return op1.asNode().compareOrder(op2.asNode()) == QXmlNodeModelIndex::Precedes ? True : False; + default: + { + Q_ASSERT(m_op == QXmlNodeModelIndex::Follows); + return op1.asNode().compareOrder(op2.asNode()) == QXmlNodeModelIndex::Follows ? True : False; + } + } +} + + +SequenceType::List NodeComparison::expectedOperandTypes() const +{ + SequenceType::List result; + result.append(CommonSequenceTypes::ZeroOrOneNode); + result.append(CommonSequenceTypes::ZeroOrOneNode); + return result; +} + +Expression::Ptr NodeComparison::compress(const StaticContext::Ptr &context) +{ + const Expression::Ptr me(PairContainer::compress(context)); + + if(me != this) + /* We're already rewritten. */ + return me; + + if(m_operand1->staticType()->cardinality().isEmpty() || + m_operand2->staticType()->cardinality().isEmpty()) + { + // TODO issue a warning in the @p context saying that one of the operands + // were empty, and that the expression always result in the empty sequence + // (which never is the intent, right?). + return EmptySequence::create(this, context); + } + + return Expression::Ptr(this); +} + +QString NodeComparison::displayName(const QXmlNodeModelIndex::DocumentOrder op) +{ + switch(op) + { + case QXmlNodeModelIndex::Is: + return QLatin1String("is"); + case QXmlNodeModelIndex::Precedes: + return QLatin1String("<<"); + default: + { + Q_ASSERT(op == QXmlNodeModelIndex::Follows); + return QLatin1String(">>"); + } + } +} + +SequenceType::Ptr NodeComparison::staticType() const +{ + if(m_operand1->staticType()->cardinality().allowsEmpty() || + m_operand2->staticType()->cardinality().allowsEmpty()) + return CommonSequenceTypes::ZeroOrOneBoolean; + else + return CommonSequenceTypes::ExactlyOneBoolean; +} + +QXmlNodeModelIndex::DocumentOrder NodeComparison::operatorID() const +{ + return m_op; +} + +ExpressionVisitorResult::Ptr NodeComparison::accept(const ExpressionVisitor::Ptr &visitor) const +{ + return visitor->visit(this); +} + +QT_END_NAMESPACE |