source: trunk/src/xmlpatterns/parser/qparsercontext_p.h@ 686

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** This file is part of the QtXmlPatterns module of the Qt Toolkit.
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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_ParserContext_H
#define Patternist_ParserContext_H

#include <QFlags>
#include <QSharedData>
#include <QStack>
#include <QStringList>
#include <QtGlobal>
#include <QXmlQuery>

#include "qbuiltintypes_p.h"
#include "qfunctionsignature_p.h"
#include "qorderby_p.h"
#include "qtemplatemode_p.h"
#include "quserfunctioncallsite_p.h"
#include "quserfunction_p.h"
#include "qvariabledeclaration_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{
    class Tokenizer;

    /**
     * @short Contains data used when parsing and tokenizing.
     *
     * When ExpressionFactory::create() is called, an instance of this class
     * is passed to the scanner and parser. It holds all information that is
     * needed to create the expression.
     *
     * @author Frans Englich <[email protected]>
     */
    class ParserContext : public QSharedData
    {
    public:
        typedef QExplicitlySharedDataPointer<ParserContext> Ptr;

        enum PrologDeclaration
        {
            BoundarySpaceDecl               = 1,
            DefaultCollationDecl            = 2,
            BaseURIDecl                     = 4,
            ConstructionDecl                = 8,
            OrderingModeDecl                = 16,
            EmptyOrderDecl                  = 32,
            CopyNamespacesDecl              = 64,
            DeclareDefaultElementNamespace  = 128,
            DeclareDefaultFunctionNamespace = 256
        };

        typedef QFlags<PrologDeclaration> PrologDeclarations;

        /**
         * Constructs a ParserContext instance.
         *
         * @param context the static context as defined in XPath. This contain
         * namespace bindings, error handler, and other information necessary
         * for creating an XPath expression.
         * @param lang the particular XPath language sub-set that should be parsed
         * @param tokenizer the Tokenizer to use.
         * @see ExpressionFactory::LanguageAccent
         */
        ParserContext(const StaticContext::Ptr &context,
                      const QXmlQuery::QueryLanguage lang,
                      Tokenizer *const tokenizer);

        /**
         * @short Removes the recently pushed variables from
         * scope. The amount of removed variables is @p amount.
         *
         * finalizePushedVariable() can be seen as popping the variable.
         *
         */
        void finalizePushedVariable(const int amount = 1,
                                    const bool shouldPop = true);

        inline VariableSlotID allocatePositionalSlot()
        {
            ++m_positionSlot;
            return m_positionSlot;
        }

        inline VariableSlotID allocateExpressionSlot()
        {
            const VariableSlotID retval = m_expressionSlot;
            ++m_expressionSlot;
            return retval;
        }

        inline VariableSlotID allocateGlobalVariableSlot()
        {
            ++m_globalVariableSlot;
            return m_globalVariableSlot;
        }

        inline bool hasDeclaration(const PrologDeclaration decl) const
        {
            return m_prologDeclarations.testFlag(decl);
        }

        inline void registerDeclaration(const PrologDeclaration decl)
        {
            m_prologDeclarations |= decl;
        }

        /**
         * The namespaces declared with <tt>declare namespace</tt>.
         */
        QStringList declaredPrefixes;