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/****************************************************************************
**
** Copyright (C) 2015 The Qt Company Ltd.
** Contact: http://www.qt.io/licensing/
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL21$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see http://www.qt.io/terms-conditions. For further
** information use the contact form at http://www.qt.io/contact-us.
**
** 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 or version 3 as published by the Free
** Software Foundation and appearing in the file LICENSE.LGPLv21 and
** LICENSE.LGPLv3 included in the packaging of this file. Please review the
** following information to ensure the GNU Lesser General Public License
** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** As a special exception, The Qt Company gives you certain additional
** rights. These rights are described in The Qt Company LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** $QT_END_LICENSE$
**
****************************************************************************/
#include "qcardinalityverifier_p.h"
#include "qcommonsequencetypes_p.h"
#include "qemptysequence_p.h"
#include "qabstractxmlforwarditerator_p.h"
#include "qliteral_p.h"
#include "qsequencemappingiterator_p.h"
#include "qexpressionsequence_p.h"
QT_BEGIN_NAMESPACE
using namespace QPatternist;
ExpressionSequence::ExpressionSequence(const Expression::List &ops) : UnlimitedContainer(ops)
{
Q_ASSERT_X(1 < ops.count(), Q_FUNC_INFO,
"It makes no sense to have an ExpressionSequence containing less than two expressions.");
}
Item::Iterator::Ptr ExpressionSequence::mapToSequence(const Expression::Ptr &expr,
const DynamicContext::Ptr &context) const
{
return expr->evaluateSequence(context);
}
Item::Iterator::Ptr ExpressionSequence::evaluateSequence(const DynamicContext::Ptr &context) const
{
return makeSequenceMappingIterator<Item>(ConstPtr(this),
makeListIterator(m_operands),
context);
}
void ExpressionSequence::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
{
Expression::List::const_iterator it(m_operands.constBegin());
const Expression::List::const_iterator end(m_operands.constEnd());
Expression::List result;
for(; it != end; ++it)
(*it)->evaluateToSequenceReceiver(context);
}
Expression::Ptr ExpressionSequence::compress(const StaticContext::Ptr &context)
{
const Expression::Ptr me(UnlimitedContainer::compress(context));
if(me != this)
return me;
Expression::List::const_iterator it(m_operands.constBegin());
const Expression::List::const_iterator end(m_operands.constEnd());
Expression::List result;
for(; it != end; ++it)
{
const ID Id = (*it)->id();
/* Remove empty sequences. This is rather important because we have some steps in the parser that
* intentionally, unconditionally and for temporary reasons create expressions like (expr, ()). Of course,
* empty sequences also occur as part of optimizations.
*
* User function call sites that are of type empty-sequence() must be avoided since
* they may contain calls to fn:error(), which we would rewrite away otherwise. */
if(Id != IDUserFunctionCallsite && (*it)->staticType()->cardinality().isEmpty())
{
/* Rewrite "(1, (), 2)" into "(1, 2)" by not
* adding (*it) to result. */
continue;
}
else if(Id == IDExpressionSequence)
{
/* Rewrite "(1, (2, 3), 4)" into "(1, 2, 3, 4)" */
Expression::List::const_iterator seqIt((*it)->operands().constBegin());
const Expression::List::const_iterator seqEnd((*it)->operands().constEnd());
for(; seqIt != seqEnd; ++seqIt)
result.append(*seqIt);
} else if (Id == IDLiteralSequence) {
/* Rewrite "(1, (2, 3), 4)" into "(1, 2, 3, 4)" */
// Note: LiteralSequence does not use the dynamic context, so we pass in a nullptr.
Item::Iterator::Ptr seqIt = (*it)->evaluateSequence(DynamicContext::Ptr(Q_NULLPTR));
while (!seqIt->next().isNull())
result.append(Literal::Ptr(new Literal(seqIt->current())));
}
else
result.append(*it);
}
if(result.isEmpty())
return EmptySequence::create(this, context);
else if(result.count() == 1)
return result.first();
else
{
m_operands = result;
return me;
}
}
Expression::Ptr ExpressionSequence::typeCheck(const StaticContext::Ptr &context,
const SequenceType::Ptr &reqType)
{
Q_ASSERT(reqType);
Expression::List::iterator it(m_operands.begin());
const Expression::List::iterator end(m_operands.end());
/* We treat the cardinality differently here by allowing the empty sequence
* for each individual Expression, since the Cardinality can be conformed to by
* the ExpressionSequence as a whole(which we check for at the end). */
const SequenceType::Ptr testOnlyIT(makeGenericSequenceType(reqType->itemType(),
Cardinality::empty() |
reqType->cardinality()));
for(; it != end; ++it)
*it = (*it)->typeCheck(context, testOnlyIT);
/* The above loop is only guaranteed to find item type errors, but the cardinality
* can still be wrong since the operands were treated individually. */
return CardinalityVerifier::verifyCardinality(Expression::Ptr(this), reqType->cardinality(), context);
}
Expression::Properties ExpressionSequence::properties() const
{
const Expression::List::const_iterator end(m_operands.constEnd());
Expression::List::const_iterator it;
bool allEvaled = true;
Expression::Properties props(DisableElimination); /* Why do we have this flag? */
for(it = m_operands.constBegin(); it != end; ++it)
{
const Expression::Properties newp((*it)->properties());
props |= newp;
if((newp & IsEvaluated) != IsEvaluated)
{
allEvaled = false;
break;
}
}
if(!allEvaled)
props &= ~IsEvaluated; /* Remove IsEvaluated. */
/* One of our children might need the focus, but we don't, so
* cut it out. */
return props & ~RequiresFocus;
}
SequenceType::Ptr ExpressionSequence::staticType() const
{
return operandsUnionType<ProductOfCardinality>();
}
SequenceType::List ExpressionSequence::expectedOperandTypes() const
{
SequenceType::List result;
/* ExpressionSequence is a bit strange type wise since it has an
* infinite amount of operands. */
result.append(CommonSequenceTypes::ZeroOrMoreItems);
return result;
}
ExpressionVisitorResult::Ptr ExpressionSequence::accept(const ExpressionVisitor::Ptr &visitor) const
{
return visitor->visit(this);
}
Expression::ID ExpressionSequence::id() const
{
return IDExpressionSequence;
}
QT_END_NAMESPACE
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