C++ Ptr::is方法代码示例

void CallTargetDescription::checkCallsiteCircularity(CallTargetDescription::List &signList,
                                                     const Expression::Ptr expr)
{
    Q_ASSERT(expr);

    if(expr->is(Expression::IDUserFunctionCallsite))
    {
        CallTargetDescription::List::const_iterator it(signList.constBegin());
        const CallTargetDescription::List::const_iterator end(signList.constEnd());
        CallSite *const callsite = static_cast<CallSite *>(expr.data());

        for(; it != end; ++it)
        {
            if(callsite->configureRecursion(*it))
            {
                /* A callsite inside the function body to the function. This user function
                 * is recursive if it's to the same function, in other words. Which it was
                 * if configureRecursion() returned true. */

                /* Now we continue and check the arguments of the callsite. That is, the arguments.
                 * This catches for instance local:foo(local:foo(3)). */
                checkArgumentsCircularity(signList, expr);
                return;
            }
        }
        /* Check the body of the function so this callsite isn't "indirectly" a
         * recursive call to the function we're checking. XQTS test case
         * default_namespace-011 is an example of this. */
        signList.append(callsite->callTargetDescription());
        checkCallsiteCircularity(signList, callsite->body());
    }

    checkArgumentsCircularity(signList, expr); /* We're done in this case. */
}

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 GenericPredicate::create(const Expression::Ptr &sourceExpression,
                                         const Expression::Ptr &predicateExpression,
                                         const StaticContext::Ptr &context,
                                         const QSourceLocation &location)
{
    Q_ASSERT(sourceExpression);
    Q_ASSERT(predicateExpression);
    Q_ASSERT(context);
    const ItemType::Ptr type(predicateExpression->staticType()->itemType());

    if(predicateExpression->is(IDIntegerValue) &&
       predicateExpression->as<Literal>()->item().as<Numeric>()->toInteger() == 1)
    { /* Handle [1] */
        return createFirstItem(sourceExpression);
    }
    else if(BuiltinTypes::numeric->xdtTypeMatches(type))
    { /* A numeric predicate, other than [1]. */
        /* TODO at somepoint we'll return a specialized expr here, NumericPredicate or so.
         * Dependency analysis is a bit tricky, since the contained expression can depend on
         * some loop component. */
        return Expression::Ptr(new GenericPredicate(sourceExpression, predicateExpression));
    }
    else if(*CommonSequenceTypes::Empty == *type)
    {
        return EmptySequence::create(predicateExpression.data(), context);
    }
    else if(*BuiltinTypes::item == *type ||
            *BuiltinTypes::xsAnyAtomicType == *type)
    {
        /* The type couldn't be narrowed at compile time, so we use
         * a generic predicate. This check is before the CommonSequenceTypes::EBV check,
         * because the latter matches these types as well. */
        return Expression::Ptr(new GenericPredicate(sourceExpression, predicateExpression));
    }
    else if(CommonSequenceTypes::EBV->itemType()->xdtTypeMatches(type))
    {
        return Expression::Ptr(new TruthPredicate(sourceExpression, predicateExpression));
    }
    else
    {
        context->error(QtXmlPatterns::tr("A value of type %1 cannot be a "
                                         "predicate. A predicate must have "
                                         "either a numeric type or an "
                                         "Effective Boolean Value type.")
                       .arg(formatType(context->namePool(),
                                       sourceExpression->staticType())),
                       ReportContext::FORG0006, location);
        return Expression::Ptr(); /* Silence compiler warning. */
    }
}

bool ByIDIdentifier::matches(const Expression::Ptr &expr) const
{
    return expr->is(m_id);
}