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//
// W A R N I N G
// -------------
//
// This file is not part of the Qt API. It exists purely as an
// implementation detail. This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
#ifndef Patternist_ReturnOrderBy_H
#define Patternist_ReturnOrderBy_H
#include "qorderby_p.h"
#include "qunlimitedcontainer_p.h"
QT_BEGIN_HEADER
QT_BEGIN_NAMESPACE
namespace QPatternist
{
/**
* @short Together with OrderBy, it implements XQuery 1.0's order by expression.
*
* ReturnOrderBy evaluates the sort keys and values, and hands it over to
* OrderBy, which is an AST ancestor, using SortTuples.
*
* @author Frans Englich
* @ingroup Patternist_expressions
*/
class ReturnOrderBy : public UnlimitedContainer
{
public:
/**
* In @p operands the first item is the return expression, and the
* rest, which is at least one, are the sort keys.
*/
ReturnOrderBy(const OrderBy::Stability stability,
const OrderBy::OrderSpec::Vector &oSpecs,
const Expression::List &operands);
virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const;
virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;
virtual SequenceType::Ptr staticType() const;
virtual SequenceType::List expectedOperandTypes() const;
virtual Expression::Ptr compress(const StaticContext::Ptr &context);
virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;
virtual ID id() const;
inline OrderBy::OrderSpec::Vector orderSpecs() const
{
return m_orderSpecs;
}
inline OrderBy::Stability stability() const
{
return m_stability;
}
/**
* In the case of that we don't have a for-expression beloning us, but
* only a let clause, this ReturnOrderBy breaks if it stays in the AST.
* So, by default we assume that we should write ourselves away, unless
* this function is called. The associated ForClause will call it
* during typeCheck(), if it exists.
*/
inline void setStay(const bool a)
{
m_flyAway = !a;
}
virtual Properties properties() const;
private:
/**
* This variable is unfortunately only used at compile time. However,
* it's tricky to get rid of it due to how QueryTransformParser would
* have to be adapted.
*/
const OrderBy::Stability m_stability;
OrderBy::OrderSpec::Vector m_orderSpecs;
/**
* @see stay()
*/
bool m_flyAway;
};
}
QT_END_NAMESPACE
QT_END_HEADER
#endif