source: trunk/src/xmlpatterns/parser/qparsercontext_p.h@ 1023

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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;

        /**
         * This is a temporary stack, used for keeping variables in scope,
         * such as for function arguments & let clauses.
         */
        VariableDeclaration::Stack variables;

        inline bool isXSLT() const
        {
            return languageAccent == QXmlQuery::XSLT20;
        }

        const StaticContext::Ptr staticContext;
        /**
         * We don't store a Tokenizer::Ptr here, because then we would get a
         * circular referencing between ParserContext and XSLTTokenizer, and
         * hence they would never destruct.
         */
        Tokenizer *const tokenizer;
        const QXmlQuery::QueryLanguage languageAccent;

        /**
         * Only used in the case of XSL-T. Is the name of the initial template
         * to call. If null, no name was provided, and regular template
         * matching should be done.
         */
        QXmlName initialTemplateName;

        /**
         * Used when parsing direct element constructors. It is used
         * for ensuring tags are well-balanced.
         */
        QStack<QXmlName> tagStack;

        /**
         * The actual expression, the Query. This member may be @c null,
         * such as in the case of an XQuery library module.
         */
        Expression::Ptr queryBody;

        /**
         * The user functions declared in the prolog.
         */
        UserFunction::List userFunctions;

        /**
         * Contains all calls to user defined functions.
         */
        UserFunctionCallsite::List userFunctionCallsites;

        /**
         * All variables declared with <tt>declare variable</tt>.
         */
        VariableDeclaration::List declaredVariables;

        inline VariableSlotID currentPositionSlot() const
        {
            return m_positionSlot;
        }

        inline VariableSlotID currentExpressionSlot() const
        {
            return m_expressionSlot;
        }

        inline void restoreNodeTestSource()
        {
            nodeTestSource = BuiltinTypes::element;
        }

        inline VariableSlotID allocateCacheSlot()
        {
            return ++m_evaluationCacheSlot;
        }

        inline VariableSlotID allocateCacheSlots(const int count)
        {
            const VariableSlotID retval = m_evaluationCacheSlot + 1;
            m_evaluationCacheSlot += count + 1;
            return retval;
        }

        ItemType::Ptr nodeTestSource;

        QStack<Expression::Ptr> typeswitchSource;

        /**
         * The library module namespace set with <tt>declare module</tt>.
         */
        QXmlName::NamespaceCode moduleNamespace;

        /**
         * When a direct element constructor is processed, resolvers are
         * created in order to carry the namespace declarations. In such case,
         * the old resolver is pushed here.
         */
        QStack<NamespaceResolver::Ptr> resolvers;

        /**
         * This is used for handling the following obscene case:
         *
         * - <tt>\<e\>{1}{1}\<\/e\></tt> produce <tt>\<e\>11\</e\></tt>
         * - <tt>\<e\>{1, 1}\<\/e\></tt> produce <tt>\<e\>1 1\</e\></tt>
         *
         * This boolean tracks whether the previous reduction inside element
         * content was done with an enclosed expression.
         */
        bool isPreviousEnclosedExpr;

        int elementConstructorDepth;

        QStack<bool> scanOnlyStack;

        QStack<OrderBy::Stability> orderStability;

        /**
         * Whether any prolog declaration that must occur after the first
         * group has been encountered.
         */
        bool hasSecondPrologPart;

        bool preserveNamespacesMode;
        bool inheritNamespacesMode;

        /**
         * Contains all named templates. Since named templates
         * can also have rules, each body may also be in templateRules.