src/xmlpatterns/functions/qsequencefns.cpp

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  41
  42 #include "qbuiltintypes_p.h"
  43 #include "qcommonsequencetypes_p.h"
  44 #include "qcommonvalues_p.h"
  45 #include "qdistinctiterator_p.h"
  46 #include "qebvextractor_p.h"
  47 #include "qemptysequence_p.h"
  48 #include "qgenericsequencetype_p.h"
  49 #include "qindexofiterator_p.h"
  50 #include "qinsertioniterator_p.h"
  51 #include "qinteger_p.h"
  52 #include "qremovaliterator_p.h"
  53 #include "qsequencegeneratingfns_p.h"
  54 #include "qsubsequenceiterator_p.h"
  55
  56 #include "qsequencefns_p.h"
  57
  58 QT_BEGIN_NAMESPACE
  59
  60 using namespace QPatternist;
  61
  62 bool BooleanFN::evaluateEBV(const DynamicContext::Ptr &context) const
  63 {
  64     return m_operands.first()->evaluateEBV(context);
  65 }
  66
  67 Expression::Ptr BooleanFN::typeCheck(const StaticContext::Ptr &context,
  68                                      const SequenceType::Ptr &reqType)
  69 {
  70     return EBVExtractor::typeCheck<FunctionCall>(context, reqType, this);
  71 }
  72
  73 Item::Iterator::Ptr IndexOfFN::evaluateSequence(const DynamicContext::Ptr &context) const
  74 {
  75     return Item::Iterator::Ptr(new IndexOfIterator(m_operands.first()->evaluateSequence(context),
  76                                                    m_operands.at(1)->evaluateSingleton(context),
  77                                                    comparator(), context,
  78                                                    ConstPtr(this)));
  79 }
  80
  81 Expression::Ptr IndexOfFN::typeCheck(const StaticContext::Ptr &context,
  82                                      const SequenceType::Ptr &reqType)
  83 {
  84     const Expression::Ptr me(FunctionCall::typeCheck(context, reqType));
  85     const ItemType::Ptr t1(m_operands.first()->staticType()->itemType());
  86     const ItemType::Ptr t2(m_operands.at(1)->staticType()->itemType());
  87
  88     if(*CommonSequenceTypes::Empty == *t1 ||
  89        *CommonSequenceTypes::Empty == *t2)
  90     {
  91         return EmptySequence::create(this, context);
  92     }
  93     else
  94     {
  95         prepareComparison(fetchComparator(t1, t2, context));
  96         return me;
  97     }
  98 }
  99
 100 Item::Iterator::Ptr DistinctValuesFN::evaluateSequence(const DynamicContext::Ptr &context) const
 101 {
 102     return Item::Iterator::Ptr(new DistinctIterator(m_operands.first()->evaluateSequence(context),
 103                                                     comparator(),
 104                                                     ConstPtr(this),
 105                                                     context));
 106 }
 107
 108 Expression::Ptr DistinctValuesFN::typeCheck(const StaticContext::Ptr &context,
 109                                             const SequenceType::Ptr &reqType)
 110 {
 111     const Expression::Ptr me(FunctionCall::typeCheck(context, reqType));
 112     const ItemType::Ptr t1(m_operands.first()->staticType()->itemType());
 113
 114     if(*CommonSequenceTypes::Empty == *t1)
 115         return EmptySequence::create(this, context);
 116     else if(!m_operands.first()->staticType()->cardinality().allowsMany())
 117         return m_operands.first();
 118     else if(BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(t1))
 119         return me;
 120     else
 121     {
 122         prepareComparison(fetchComparator(t1, t1, context));
 123         return me;
 124     }
 125 }
 126
 127 SequenceType::Ptr DistinctValuesFN::staticType() const
 128 {
 129     const SequenceType::Ptr t(m_operands.first()->staticType());
 130     return makeGenericSequenceType(t->itemType(),
 131                                    t->cardinality().allowsMany() ? Cardinality::oneOrMore()
 132                                                                  : Cardinality::exactlyOne());
 133 }
 134
 135 Item::Iterator::Ptr InsertBeforeFN::evaluateSequence(const DynamicContext::Ptr &context) const
 136 {
 137     const Item::Iterator::Ptr target(m_operands.first()->evaluateSequence(context));
 138     const Item::Iterator::Ptr inserts(m_operands.at(2)->evaluateSequence(context));
 139
 140     xsInteger position = m_operands.at(1)->evaluateSingleton(context).as<Numeric>()->toInteger();
 141
 142     if(position < 1)
 143         position = 1;
 144
 145     return Item::Iterator::Ptr(new InsertionIterator(target, position, inserts));
 146 }
 147
 148 Item InsertBeforeFN::evaluateSingleton(const DynamicContext::Ptr &context) const
 149 {
 150     return evaluateSequence(context)->next();
 151 }
 152
 153 SequenceType::Ptr InsertBeforeFN::staticType() const
 154 {
 155     const SequenceType::Ptr t1(m_operands.first()->staticType());
 156     const SequenceType::Ptr t2(m_operands.last()->staticType());
 157
 158     return makeGenericSequenceType(t1->itemType() | t2->itemType(),
 159                                    t1->cardinality() + t2->cardinality());
 160 }
 161
 162 Item::Iterator::Ptr RemoveFN::evaluateSequence(const DynamicContext::Ptr &context) const
 163 {
 164     const xsInteger pos = m_operands.last()->evaluateSingleton(context).as<Numeric>()->toInteger();
 165     Item::Iterator::Ptr it(m_operands.first()->evaluateSequence(context));
 166
 167     if(pos < 1)
 168         return it;
 169
 170     return Item::Iterator::Ptr(new RemovalIterator(it, pos));
 171 }
 172
 173 Item RemoveFN::evaluateSingleton(const DynamicContext::Ptr &context) const
 174 {
 175     const xsInteger pos = m_operands.last()->evaluateSingleton(context).as<Numeric>()->toInteger();
 176     if(pos <= 1)
 177         return Item();
 178
 179     return m_operands.first()->evaluateSingleton(context);
 180 }
 181
 182 SequenceType::Ptr RemoveFN::staticType() const
 183 {
 184     const SequenceType::Ptr opType(m_operands.first()->staticType());
 185     const Cardinality c(opType->cardinality());
 186
 187     if(c.minimum() == 0)
 188         return makeGenericSequenceType(opType->itemType(), c);
 189     else
 190     {
 191         return makeGenericSequenceType(opType->itemType(),
 192                                        Cardinality::fromRange(c.minimum() - 1,
 193                                                               c.maximum()));
 194     }
 195 }
 196
 197 Item::Iterator::Ptr ReverseFN::evaluateSequence(const DynamicContext::Ptr &context) const
 198 {
 199     return m_operands.first()->evaluateSequence(context)->toReversed();
 200 }
 201
 202 Expression::Ptr ReverseFN::typeCheck(const StaticContext::Ptr &context,
 203                                      const SequenceType::Ptr &reqType)
 204 {
 205     if(m_operands.first()->staticType()->cardinality().allowsMany())
 206         return FunctionCall::typeCheck(context, reqType);
 207     else
 208         return m_operands.first()->typeCheck(context, reqType);
 209 }
 210
 211 SequenceType::Ptr ReverseFN::staticType() const
 212 {
 213     return m_operands.first()->staticType();
 214 }
 215
 216 SubsequenceFN::SubsequenceFN() : m_hasTypeChecked(false)
 217 {
 218 }
 219
 220 Expression::Ptr SubsequenceFN::typeCheck(const StaticContext::Ptr &context,
 221                                          const SequenceType::Ptr &reqType)
 222 {
 223     m_hasTypeChecked = true;
 224     return FunctionCall::typeCheck(context, reqType);
 225 }
 226
 227 Item::Iterator::Ptr SubsequenceFN::evaluateSequence(const DynamicContext::Ptr &context) const
 228 {
 229     Item::Iterator::Ptr it(m_operands.first()->evaluateSequence(context));
 230
 231     xsInteger startingLoc = m_operands.at(1)->evaluateSingleton(context).as<Numeric>()->round()->toInteger();
 232     xsInteger length = -1;
 233
 234     if(m_operands.count() == 3)
 235     {
 236         length = m_operands.last()->evaluateSingleton(context).as<Numeric>()->toInteger();
 237
 238         if(startingLoc + length < 1 || (startingLoc > (startingLoc + length)))
 239             return CommonValues::emptyIterator;
 240     }
 241
 242     /* F&O, 15.1.10, "If $startingLoc is zero or negative, the
 243      * subsequence includes items from the beginning of the $sourceSeq." */
 244     if(startingLoc < 1)
 245         startingLoc = 1;
 246
 247     if(length < 1 && length != -1)
 248         return CommonValues::emptyIterator;
 249     return Item::Iterator::Ptr(new SubsequenceIterator(it, startingLoc, length));
 250 }
 251
 252 Item SubsequenceFN::evaluateSingleton(const DynamicContext::Ptr &context) const
 253 {
 254     return evaluateSequence(context)->next();
 255 }
 256
 257 Expression::Ptr SubsequenceFN::compress(const StaticContext::Ptr &context)
 258 {
 259     const Expression::Ptr me(FunctionCall::compress(context));
 260     if(me != this)
 261         return me;
 262
 263     const Expression::Ptr lenArg(m_operands.value(2));
 264     if(lenArg && lenArg->isEvaluated())
 265     {
 266         const xsInteger length = lenArg->as<Literal>()->item().as<Numeric>()->round()->toInteger();
 267
 268         if(length <= 0)
 269             return EmptySequence::create(this, context);
 270     }
 271
 272     return me;
 273 }
 274
 275 SequenceType::Ptr SubsequenceFN::staticType() const
 276 {
 277     const SequenceType::Ptr opType(m_operands.first()->staticType());
 278     const Cardinality opCard(opType->cardinality());
 279
 280     /* Optimization: we can do much stronger inference here. If the length is a
 281      * constant, we can constrain the range at least upwards of the
 282      * cardinality, for instance. */
 283
 284     /* The subsequence(expr, 1, 1), add empty-sequence() to the static type.
 285      *
 286      * Note that we cannot do all these inferences before we've typechecked our
 287      * operands. The only known case of where our staticType() is called before
 288      * typeCheck() is through xmlpatternsview, although it wouldn't be
 289      * surprising if the more exotic paths can achieve that too.
 290      */
 291     if(m_hasTypeChecked &&
 292        m_operands.at(1)->isEvaluated()                                                      &&
 293        m_operands.count() == 3                                                              &&
 294        m_operands.at(2)->isEvaluated()                                                      &&
 295        m_operands.at(1)->as<Literal>()->item().as<Numeric>()->round()->toInteger() == 1     &&
 296        m_operands.at(2)->as<Literal>()->item().as<Numeric>()->round()->toInteger() == 1)
 297     {
 298         return makeGenericSequenceType(opType->itemType(),
 299                                        opCard.toWithoutMany());
 300     }
 301     else
 302     {
 303         return makeGenericSequenceType(opType->itemType(),
 304                                        opCard | Cardinality::zeroOrOne());
 305     }
 306 }
 307
 308 Expression::Ptr DocFN::typeCheck(const StaticContext::Ptr &context,
 309                                  const SequenceType::Ptr &reqType)
 310 {
 311     /* See the doxygen documentation for this function for the explanation
 312      * to why this implementation is here, as opposed to in
 313      * qsequencegeneratingfns.cpp. */
 314
 315     Q_ASSERT(context);
 316
 317     prepareStaticBaseURI(context);
 318
 319     const Expression::Ptr uriOp(m_operands.first());
 320
 321     if(!uriOp->isEvaluated())
 322         return Expression::Ptr(FunctionCall::typeCheck(context, reqType));
 323
 324     const Item uriItem(uriOp->evaluateSingleton(context->dynamicContext()));
 325
 326     if(!uriItem)
 327         return EmptySequence::create(this, context)->typeCheck(context, reqType); // TODO test this
 328
 329     /* These two lines were previously in a separate function but are now duplicated
 330      * in DocFN::evaluateSingleton(), as part of a workaround for solaris-cc-64. */
 331     const QUrl mayRela(AnyURI::toQUrl<ReportContext::FODC0005>(uriItem.stringValue(), context, this));
 332     const QUrl uri(context->resolveURI(mayRela, staticBaseURI()));
 333
 334     /* The URI is supplied statically, so, let's try to be clever. */
 335     Q_ASSERT_X(context->resourceLoader(), Q_FUNC_INFO,
 336                "No resource loader is set in the StaticContext.");
 337     m_type = context->resourceLoader()->announceDocument(uri, ResourceLoader::MayUse);
 338
 339     if(m_type)
 340     {
 341         Q_ASSERT(CommonSequenceTypes::ZeroOrOneDocumentNode->matches(m_type));
 342         return Expression::Ptr(FunctionCall::typeCheck(context, reqType));
 343     }
 344     else
 345     {
 346         context->error(QtXmlPatterns::tr("It will not be possible to retrieve %1.").arg(formatURI(uri)),
 347                        ReportContext::FODC0002, this);
 348         return Expression::Ptr();
 349     }
 350 }
 351
 352 QT_END_NAMESPACE