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** This file is part of the QtXmlPatterns module of the Qt Toolkit.

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#include "qabstractfloat_p.h"

#include "qboolean_p.h"

#include "qbuiltintypes_p.h"

#include "qcommonsequencetypes_p.h"

#include "qemptysequence_p.h"

#include "qfirstitempredicate_p.h"

#include "qgenericsequencetype_p.h"

#include "qitemmappingiterator_p.h"

#include "qliteral_p.h"

#include "qpatternistlocale_p.h"

#include "qtruthpredicate_p.h"

#include "qgenericpredicate_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

GenericPredicate::GenericPredicate(const Expression::Ptr &sourceExpression,

                                   const Expression::Ptr &predicate) : PairContainer(sourceExpression,

                                                                                     predicate)

{

}

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. */

    }

}

Expression::Ptr GenericPredicate::createFirstItem(const Expression::Ptr &sourceExpression)

{

    return Expression::Ptr(new FirstItemPredicate(sourceExpression));

}

Item GenericPredicate::mapToItem(const Item &item,

                                 const DynamicContext::Ptr &context) const

{

    const Item::Iterator::Ptr it(m_operand2->evaluateSequence(context));

    const Item pcateItem(it->next());

    if(!pcateItem)

        return Item(); /* The predicate evaluated to the empty sequence */

    else if(pcateItem.isNode())

        return item;

    /* Ok, now it must be an AtomicValue */

    else if(BuiltinTypes::numeric->xdtTypeMatches(pcateItem.type()))

    { /* It's a positional predicate. */

        if(it->next())

        {

            context->error(QtXmlPatterns::tr("A positional predicate must "

                                             "evaluate to a single numeric "

                                             "value."),

                              ReportContext::FORG0006, this);

            return Item();

        }

        if(Double::isEqual(static_cast<xsDouble>(context->contextPosition()),

                           pcateItem.as<Numeric>()->toDouble()))

        {

            return item;

        }

        else

            return Item();

    }

    else if(Boolean::evaluateEBV(pcateItem, it, context)) /* It's a truth predicate. */

        return item;

    else

        return Item();

}

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);

}

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);

}

SequenceType::List GenericPredicate::expectedOperandTypes() const

{

    SequenceType::List result;

    result.append(CommonSequenceTypes::ZeroOrMoreItems);

    result.append(CommonSequenceTypes::ZeroOrMoreItems);

    return result;

}

SequenceType::Ptr GenericPredicate::staticType() const

{

    const SequenceType::Ptr type(m_operand1->staticType());

    return makeGenericSequenceType(type->itemType(),

                                   type->cardinality() | Cardinality::zeroOrOne());

}

ExpressionVisitorResult::Ptr GenericPredicate::accept(const ExpressionVisitor::Ptr &visitor) const

{

    return visitor->visit(this);

}

ItemType::Ptr GenericPredicate::newFocusType() const

{

    return m_operand1->staticType()->itemType();

}

Expression::Properties GenericPredicate::properties() const

{

    return CreatesFocusForLast;

}

QString GenericPredicate::description() const

{

    return QLatin1String("predicate");

}

Expression::ID GenericPredicate::id() const

{

    return IDGenericPredicate;

}

QT_END_NAMESPACE