C++ Ptr::dynamicContext方法代码示例

Expression::Ptr PatternPlatform::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr me(FunctionCall::compress(context));
    if(me != this)
        return me;

    if(m_operands.at(1)->is(IDStringValue))
    {
        const DynamicContext::Ptr dynContext(context->dynamicContext());

        m_pattern = parsePattern(m_operands.at(1)->evaluateSingleton(dynContext).stringValue(),
                                 dynContext);
        m_compiledParts |= PatternPrecompiled;
    }

    const Expression::Ptr flagOperand(m_operands.value(m_flagsPosition));

    if(!flagOperand)
    {
        m_flags = NoFlags;
        m_compiledParts |= FlagsPrecompiled;
    }
    else if(flagOperand->is(IDStringValue))
    {
        const DynamicContext::Ptr dynContext(context->dynamicContext());
        m_flags = parseFlags(flagOperand->evaluateSingleton(dynContext).stringValue(),
                             dynContext);
        m_compiledParts |= FlagsPrecompiled;
    }

    if(m_compiledParts == FlagsAndPattern)
        applyFlags(m_flags, m_pattern);

    return me;
}

Expression::Ptr AndExpression::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr newMe(PairContainer::compress(context));

    if(newMe != this)
        return newMe;

    /* Both operands mustn't be evaluated in order to be able to compress. */
    if(m_operand1->isEvaluated() && !m_operand1->evaluateEBV(context->dynamicContext()))
        return wrapLiteral(CommonValues::BooleanFalse, context, this);
    else if(m_operand2->isEvaluated() && !m_operand2->evaluateEBV(context->dynamicContext()))
        return wrapLiteral(CommonValues::BooleanFalse, context, this);
    else
        return Expression::Ptr(this);
}

Expression::Ptr Expression::constantPropagate(const StaticContext::Ptr &context) const
{
    Q_ASSERT(context);

    /* Optimization: We rewrite literals to literals here, which is pointless.
     * Maybe we should have a property which says "doesn't disable elimination
     * but don't eliminate me." */
    if(staticType()->cardinality().allowsMany())
    {
        Item::Iterator::Ptr it(evaluateSequence(context->dynamicContext()));
        Item::List result;
        Item item(it->next());

        while(item)
        {
            result.append(item);
            item = it->next();
        }

        switch(result.count())
        {
            case 0:
                return EmptySequence::create(this, context);
            case 1:
                return rewrite(Expression::Ptr(new Literal(result.first())), context);
            default:
                return rewrite(Expression::Ptr(new LiteralSequence(result)), context);
        }
    }
    else
    {
        const Item item(evaluateSingleton(context->dynamicContext()));

        if(item)
            return rewrite(Expression::Ptr(new Literal(item)), context);
        else
            return EmptySequence::create(this, context);
    }
}

Expression::Ptr ReplaceFN::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr me(PatternPlatform::compress(context));

    if(me != this)
        return me;

    if(m_operands.at(2)->is(IDStringValue))
    {
        const int capt = captureCount();
        if(capt == -1)
            return me;
        else
            m_replacementString = parseReplacement(captureCount(), context->dynamicContext());
    }

    return me;
}

Expression::Ptr DocFN::typeCheck(const StaticContext::Ptr &context,
                                 const SequenceType::Ptr &reqType)
{
    /* See the doxygen documentation for this function for the explanation
     * to why this implementation is here, as opposed to in
     * qsequencegeneratingfns.cpp. */

    Q_ASSERT(context);

    prepareStaticBaseURI(context);

    const Expression::Ptr uriOp(m_operands.first());

    if(!uriOp->isEvaluated())
        return Expression::Ptr(FunctionCall::typeCheck(context, reqType));

    const Item uriItem(uriOp->evaluateSingleton(context->dynamicContext()));

    if(!uriItem)
        return EmptySequence::create(this, context)->typeCheck(context, reqType); // TODO test this

    /* These two lines were previously in a separate function but are now duplicated
     * in DocFN::evaluateSingleton(), as part of a workaround for solaris-cc-64. */
    const QUrl mayRela(AnyURI::toQUrl<ReportContext::FODC0005>(uriItem.stringValue(), context, this));
    const QUrl uri(context->resolveURI(mayRela, staticBaseURI()));

    /* The URI is supplied statically, so, let's try to be clever. */
    Q_ASSERT_X(context->resourceLoader(), Q_FUNC_INFO,
               "No resource loader is set in the StaticContext.");
    m_type = context->resourceLoader()->announceDocument(uri, ResourceLoader::MayUse);

    if(m_type)
    {
        Q_ASSERT(CommonSequenceTypes::ZeroOrOneDocumentNode->matches(m_type));
        return Expression::Ptr(FunctionCall::typeCheck(context, reqType));
    }
    else
    {
        context->error(QtXmlPatterns::tr("It will not be possible to retrieve %1.").arg(formatURI(uri)),
                       ReportContext::FODC0002, this);
        return Expression::Ptr();
    }
}

Expression::Ptr IfThenClause::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr me(TripleContainer::compress(context));

    if(me != this)
        return me;

    /* All operands mustn't be evaluated in order for const folding to
     * be possible. Let's see how far we get. */

    if(m_operand1->isEvaluated())
    {
        if(m_operand1->evaluateEBV(context->dynamicContext()))
            return m_operand2;
        else
            return m_operand3;
    }
    else
        return me;
}

Expression::Ptr NormalizeUnicodeFN::compress(const StaticContext::Ptr &context)
{
    const Expression::Ptr me(FunctionCall::compress(context));
    if(me != this)
        return me;

    Q_ASSERT(m_operands.count() == 1 || m_operands.count() == 2);

    if(m_operands.count() == 1)
        m_normForm = QString::NormalizationForm_C;
    else if(m_operands.last()->is(IDStringValue))
    {
        m_normForm = static_cast<QString::NormalizationForm>(
                determineNormalizationForm(context->dynamicContext()));

        if(m_normForm == -1)
            return m_operands.first();

        /* Remove the operand since we don't need it anymore. */
        m_operands.removeLast();
    }

    return me;
}