C++ Ptr::setFocusIterator方法代码示例

Item GenericPredicate::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    const Item::Iterator::Ptr focus(m_operand1->evaluateSequence(context));
    const DynamicContext::Ptr newContext(context->createFocus());
    newContext->setFocusIterator(focus);
    return mapToItem(focus->next(), newContext);
}

Item::Iterator::Ptr ApplyTemplate::evaluateSequence(const DynamicContext::Ptr &context) const
{
    const TemplateMode::Ptr templateMode(effectiveMode(context));
    const Template::Ptr &templateMatch = findTemplate(context, templateMode);

    if(templateMatch)
        return templateMatch->body->evaluateSequence(templateMatch->createContext(this, context, false));
    else
    {
        /* None of our templates matched. Proceed with a built-in. */
        const Item current(context->contextItem());
        // TODO it can be an atomic value?
        const QXmlNodeModelIndex::NodeKind kind(current.asNode().kind());

        if(kind == QXmlNodeModelIndex::Element || kind == QXmlNodeModelIndex::Document)
        {
            pDebug() << "No template match, using builtin template for element() | document-node()";

            const Item::Iterator::Ptr focusIterator(makeItemMappingIterator<Item>(ConstPtr(this),
                                                    current.asNode().iterate(QXmlNodeModelIndex::AxisChild),
                                                    context));

            const DynamicContext::Ptr focus(context->createFocus());
            focus->setFocusIterator(focusIterator);
            return makeSequenceMappingIterator<Item>(ConstPtr(this), focusIterator, focus);
        }
        return CommonValues::emptyIterator;
    }
}

Item::Iterator::Ptr GenericPredicate::evaluateSequence(const DynamicContext::Ptr &context) const
{
    const Item::Iterator::Ptr focus(m_operand1->evaluateSequence(context));
    const DynamicContext::Ptr newContext(context->createFocus());
    newContext->setFocusIterator(focus);

    return makeItemMappingIterator<Item>(ConstPtr(this),
                                         focus,
                                         newContext);
}

void Path::evaluateToSequenceReceiver(const DynamicContext::Ptr &context) const
{
    /* Note, we use the old context for m_operand1. */
    const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));

    const DynamicContext::Ptr focus(context->createFocus());
    focus->setFocusIterator(source);

    while(source->next())
        m_operand2->evaluateToSequenceReceiver(focus);
}

Item::Iterator::Ptr Path::evaluateSequence(const DynamicContext::Ptr &context) const
{
    /* Note, we use the old context for m_operand1. */
    const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));

    const DynamicContext::Ptr focus(context->createFocus());
    focus->setFocusIterator(source);

    const Item::Iterator::Ptr result(makeSequenceMappingIterator<Item>(ConstPtr(this), source, focus));

    if(m_checkXPTY0018)
    {
        /* This is an expensive code path, but it should happen very rarely. */

        enum FoundItem
        {
            FoundNone,
            FoundNode,
            FoundAtomicValue
        } hasFound = FoundNone;

        Item::List whenChecked;

        Item next(result->next());

        while(next)
        {
            const FoundItem found = next.isAtomicValue() ? FoundAtomicValue : FoundNode;

            if(hasFound != FoundNone && hasFound != found)
            {
                /* It's an atomic value and we've already found a node. Mixed content. */
                context->error(QtXmlPatterns::tr("The last step in a path must contain either nodes "
                                                 "or atomic values. It cannot be a mixture between the two."),
                               ReportContext::XPTY0018, this);
            }
            else
                hasFound = found;

            whenChecked.append(next);
            next = result->next();
        }

        return makeListIterator(whenChecked);
    }
    else
        return result;
}

Item Path::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    /* This function is called if both operands' cardinality is exactly-one. Therefore
     * we manually go forward in the focus by calling next().
     *
     * We don't check for XPTY0018, only in evaluateSequence(), since if we're guaranteed
     * to evaluate to one item, we can only evaluate to one node or one atomic value.
     */

    /* Note, we use the old context for m_operand1. */
    const Item::Iterator::Ptr source(m_operand1->evaluateSequence(context));

    const DynamicContext::Ptr focus(context->createFocus());
    focus->setFocusIterator(source);

    /* This test is needed because if the focus is empty, we don't want to(nor can't) evaluate
     * the next step. */
    // TODO Why are we at all invoked then?
    if(source->next())
        return m_operand2->evaluateSingleton(focus);
    else
        return Item();
}