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     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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

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    40 ****************************************************************************/

    41 

    42 #include "qabstractfloat_p.h"

    43 #include "qboolean_p.h"

    44 #include "qbuiltintypes_p.h"

    45 #include "qcommonsequencetypes_p.h"

    46 #include "qemptysequence_p.h"

    47 #include "qfirstitempredicate_p.h"

    48 #include "qgenericsequencetype_p.h"

    49 #include "qitemmappingiterator_p.h"

    50 #include "qliteral_p.h"

    51 #include "qpatternistlocale_p.h"

    52 #include "qtruthpredicate_p.h"

    53 

    54 #include "qgenericpredicate_p.h"

    55 

    56 QT_BEGIN_NAMESPACE

    57 

    58 using namespace QPatternist;

    59 

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

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

    62                                                                                      predicate)

    63 {

    64 }

    65 

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

    67                                          const Expression::Ptr &predicateExpression,

    68                                          const StaticContext::Ptr &context,

    69                                          const QSourceLocation &location)

    70 {

    71     Q_ASSERT(sourceExpression);

    72     Q_ASSERT(predicateExpression);

    73     Q_ASSERT(context);

    74     const ItemType::Ptr type(predicateExpression->staticType()->itemType());

    75 

    76     if(predicateExpression->is(IDIntegerValue) &&

    77        predicateExpression->as<Literal>()->item().as<Numeric>()->toInteger() == 1)

    78     { /* Handle [1] */

    79         return createFirstItem(sourceExpression);

    80     }

    81     else if(BuiltinTypes::numeric->xdtTypeMatches(type))

    82     { /* A numeric predicate, other than [1]. */

    83         /* TODO at somepoint we'll return a specialized expr here, NumericPredicate or so.

    84          * Dependency analysis is a bit tricky, since the contained expression can depend on

    85          * some loop component. */

    86         return Expression::Ptr(new GenericPredicate(sourceExpression, predicateExpression));

    87     }

    88     else if(*CommonSequenceTypes::Empty == *type)

    89     {

    90         return EmptySequence::create(predicateExpression.data(), context);

    91     }

    92     else if(*BuiltinTypes::item == *type ||

    93             *BuiltinTypes::xsAnyAtomicType == *type)

    94     {

    95         /* The type couldn't be narrowed at compile time, so we use

    96          * a generic predicate. This check is before the CommonSequenceTypes::EBV check,

    97          * because the latter matches these types as well. */

    98         return Expression::Ptr(new GenericPredicate(sourceExpression, predicateExpression));

    99     }

   100     else if(CommonSequenceTypes::EBV->itemType()->xdtTypeMatches(type))

   101     {

   102         return Expression::Ptr(new TruthPredicate(sourceExpression, predicateExpression));

   103     }

   104     else

   105     {

   106         context->error(QtXmlPatterns::tr("A value of type %1 cannot be a "

   107                                          "predicate. A predicate must have "

   108                                          "either a numeric type or an "

   109                                          "Effective Boolean Value type.")

   110                        .arg(formatType(context->namePool(),

   111                                        sourceExpression->staticType())),

   112                        ReportContext::FORG0006, location);

   113         return Expression::Ptr(); /* Silence compiler warning. */

   114     }

   115 }

   116 

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

   118 

   119 {

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

   121 }

   122 

   123 Item GenericPredicate::mapToItem(const Item &item,

   124                                  const DynamicContext::Ptr &context) const

   125 {

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

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

   128 

   129     if(!pcateItem)

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

   131     else if(pcateItem.isNode())

   132         return item;

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

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

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

   136         if(it->next())

   137         {

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

   139                                              "evaluate to a single numeric "

   140                                              "value."),

   141                               ReportContext::FORG0006, this);

   142             return Item();

   143         }

   144 

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

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

   147         {

   148             return item;

   149         }

   150         else

   151             return Item();

   152     }

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

   154         return item;

   155     else

   156         return Item();

   157 }

   158 

   159 Item::Iterator::Ptr GenericPredicate::evaluateSequence(const DynamicContext::Ptr &context) const

   160 {

   161     const Item::Iterator::Ptr focus(m_operand1->evaluateSequence(context));

   162     const DynamicContext::Ptr newContext(context->createFocus());

   163     newContext->setFocusIterator(focus);

   164 

   165     return makeItemMappingIterator<Item>(ConstPtr(this),

   166                                          focus,

   167                                          newContext);

   168 }

   169 

   170 Item GenericPredicate::evaluateSingleton(const DynamicContext::Ptr &context) const

   171 {

   172     const Item::Iterator::Ptr focus(m_operand1->evaluateSequence(context));

   173     const DynamicContext::Ptr newContext(context->createFocus());

   174     newContext->setFocusIterator(focus);

   175     return mapToItem(focus->next(), newContext);

   176 }

   177 

   178 SequenceType::List GenericPredicate::expectedOperandTypes() const

   179 {

   180     SequenceType::List result;

   181     result.append(CommonSequenceTypes::ZeroOrMoreItems);

   182     result.append(CommonSequenceTypes::ZeroOrMoreItems);

   183     return result;

   184 }

   185 

   186 SequenceType::Ptr GenericPredicate::staticType() const

   187 {

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

   189     return makeGenericSequenceType(type->itemType(),

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

   191 }

   192 

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

   194 {

   195     return visitor->visit(this);

   196 }

   197 

   198 ItemType::Ptr GenericPredicate::newFocusType() const

   199 {

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

   201 }

   202 

   203 Expression::Properties GenericPredicate::properties() const

   204 {

   205     return CreatesFocusForLast;

   206 }

   207 

   208 QString GenericPredicate::description() const

   209 {

   210     return QLatin1String("predicate");

   211 }

   212 

   213 Expression::ID GenericPredicate::id() const

   214 {

   215     return IDGenericPredicate;

   216 }

   217 

   218 QT_END_NAMESPACE