source: trunk/src/xmlpatterns/parser/qxslttokenizer_p.h@ 281

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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_XSLTTokenizer_H
#define Patternist_XSLTTokenizer_H

#include <QQueue>
#include <QStack>
#include <QUrl>

#include "qmaintainingreader_p.h"
#include "qreportcontext_p.h"
#include "qtokenizer_p.h"
#include "qxslttokenlookup_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist
{
    /**
     * @short A TokenSource which contains one Tokenizer::Token.
     *
     * One possible way to optimize this is to let SingleTokenContainer
     * actually contain a list of tokens, such that XSLTTokenizer::queueToken()
     * could append to that, instead of instansiating a SingleTokenContainer
     * all the time.
     *
     * @author Frans Englich <[email protected]>
     */
    class SingleTokenContainer : public TokenSource
    {
    public:
        inline SingleTokenContainer(const Tokenizer::Token &token,
                                    const YYLTYPE &location);

        virtual Tokenizer::Token nextToken(YYLTYPE *const sourceLocator);
    private:
        const Tokenizer::Token m_token;
        const YYLTYPE          m_location;
        bool                   m_hasDelivered;
    };

    SingleTokenContainer::SingleTokenContainer(const Tokenizer::Token &token,
                                               const YYLTYPE &location) : m_token(token)
                                                                        , m_location(location)
                                                                        , m_hasDelivered(false)
    {
    }

    /**
     * @short Tokenizes XSL-T 2.0 documents.
     *
     * XSLTTokenizer takes in its constructor a pointer to a QIODevice which is
     * supposed to contain an XSL-T document. XSLTTokenizer then rewrites that
     * document into XQuery tokens delivered via nextToken(), which the regular
     * XQuery parser then reads. Hence, the XSL-T language is rewritten into
     * XQuery code, slightly extended to handle the featuress specific to
     * XSL-T.
     *
     * @author Frans Englich <[email protected]>
     */
    class XSLTTokenizer : public Tokenizer
                        , private MaintainingReader<XSLTTokenLookup>
    {
    public:
        /**
         * XSLTTokenizer do not own @p queryDevice.
         */
        XSLTTokenizer(QIODevice *const queryDevice,
                      const QUrl &location,
                      const ReportContext::Ptr &context,
                      const NamePool::Ptr &np);

        virtual Token nextToken(YYLTYPE *const sourceLocator);

        /**
         * For XSLT we don't need this mechanism, so we do nothing.
         */
        virtual int commenceScanOnly();

        /**
         * For XSLT we don't need this mechanism, so we do nothing.
         */
        virtual void resumeTokenizationFrom(const int position);

        virtual void setParserContext(const ParserContext::Ptr &parseInfo);

        virtual QUrl documentURI() const
        {
            return queryURI();
        }

    protected:
        virtual bool isAnyAttributeAllowed() const;

    private:
        inline void validateElement() const;

        YYLTYPE currentSourceLocator() const;

        enum State
        {
            OutsideDocumentElement,
            InsideStylesheetModule,
            InsideSequenceConstructor
        };

        enum VariableType
        {
            FunctionParameter,
            GlobalParameter,
            TemplateParameter,
            VariableDeclaration,
            VariableInstruction,
            WithParamVariable
        };

        void queueNamespaceDeclarations(TokenSource::Queue *const ts,
                                        QStack<Token> *const target,
                                        const bool isDeclaration = false);

        inline void queueToken(const Token &token,
                               TokenSource::Queue *const ts);
        void queueEmptySequence(TokenSource::Queue *const to);
        void queueSequenceType(const QString &expr);
        /**
         * If @p emptynessAllowed is @c true, the @c select attribute may
         * be empty while there also is no sequence constructor.
         */
        void queueSimpleContentConstructor(const ReportContext::ErrorCode code,
                                           const bool emptynessAllowed,
                                           TokenSource::Queue *const to,
                                           const bool selectOnlyFirst = false);
        /**
         * Tokenizes and queues @p expr as if it was an attribute value
         * template.
         */
        void queueAVT(const QString &expr,
                      TokenSource::Queue *const to);

        void hasWrittenExpression(bool &beacon);
        void commencingExpression(bool &hasWrittenExpression,
                                  TokenSource::Queue *const to);

        void outsideDocumentElement();
        void insideChoose(TokenSource::Queue *const to);
        void insideFunction();

        bool attributeYesNo(const QString &localName) const;

        /**
         * Scans/skips @c xsl:fallback elements only. This is the case of the
         * children of @c xsl:sequence, for instance.
         */
        void parseFallbacksOnly();

        /**
         * Returns true if the current element is either @c stylesheet
         * or the synonym @c transform.
         *
         * This function assumes that m_reader is positioned at an element
         * and that the namespace is XSL-T.
         */
        bool isStylesheetElement() const;

        /**
         * Returns true if the current element name is @p name.
         *
         * It is assumed that the namespace is XSL-T and that the current
         * state in m_reader is either QXmlStreamReader::StartElement or
         * QXmlStreamReader::EndElement.