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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_ExpressionVariableReference_H
#define Patternist_ExpressionVariableReference_H

#include "qvariabledeclaration_p.h"
#include "qvariablereference_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{
    /**
     * @short A reference to a variable declared with <tt>declare variable</tt> or @c let.
     *
     * It's also used by variable bindings in @c case branches of the @c typeswitch
     * expression.
     *
     * This AST node is only used up until the typeCheck() stage. Therefore it
     * has no functions for evaluation, such as evaluateSequence().
     *
     * @author Frans Englich <fenglich@trolltech.com>
     * @ingroup Patternist_expressions
     */
    class ExpressionVariableReference : public VariableReference
    {
    public:
        ExpressionVariableReference(const VariableSlotID slot,
                                    const VariableDeclaration::Ptr &varDecl);

        virtual bool evaluateEBV(const DynamicContext::Ptr &context) const;
        virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const;
        virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const;

        virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context,
                                          const SequenceType::Ptr &reqType);
        virtual SequenceType::Ptr staticType() const;
        virtual ID id() const;
        virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const;

        inline const Expression::Ptr &sourceExpression() const;
        inline const VariableDeclaration::Ptr &variableDeclaration() const;
    private:
        const VariableDeclaration::Ptr m_varDecl;
    };

    inline const Expression::Ptr &ExpressionVariableReference::sourceExpression() const
    {
        return m_varDecl->expression();
    }

    inline const VariableDeclaration::Ptr &ExpressionVariableReference::variableDeclaration() const
    {
        return m_varDecl;
    }

}

QT_END_NAMESPACE

QT_END_HEADER

#endif