C++ Ptr::evaluateSingleton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 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();
    }
}

QRegExp PatternPlatform::pattern(const DynamicContext::Ptr &context) const
{
    if(m_compiledParts == FlagsAndPattern) /* This is the most common case. */
    {
        Q_ASSERT(m_pattern.isValid());
        return m_pattern;
    }

    QRegExp retvalPattern;
    Flags flags;

    /* Compile the flags, if necessary. */
    if(m_compiledParts.testFlag(FlagsPrecompiled))
        flags = m_flags;
    else
    {
        const Expression::Ptr flagsOp(m_operands.value(m_flagsPosition));

        if(flagsOp)
            flags = parseFlags(flagsOp->evaluateSingleton(context).stringValue(), context);
        else
            flags = NoFlags;
    }

    /* Compile the pattern, if necessary. */
    if(m_compiledParts.testFlag(PatternPrecompiled))
        retvalPattern = m_pattern;
    else
    {
        retvalPattern = parsePattern(m_operands.at(1)->evaluateSingleton(context).stringValue(),
                                     context);

    }

    applyFlags(flags, retvalPattern);

    Q_ASSERT(m_pattern.isValid());
    return retvalPattern;
}