src/xmlpatterns/expr/qarithmeticexpression.cpp

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  41
  42 #include "qboolean_p.h"
  43 #include "qbuiltintypes_p.h"
  44 #include "qcommonsequencetypes_p.h"
  45 #include "qemptysequence_p.h"
  46 #include "qgenericsequencetype_p.h"
  47 #include "qliteral_p.h"
  48 #include "qpatternistlocale_p.h"
  49 #include "qschemanumeric_p.h"
  50 #include "quntypedatomicconverter_p.h"
  51
  52 #include "qarithmeticexpression_p.h"
  53
  54 QT_BEGIN_NAMESPACE
  55
  56 using namespace QPatternist;
  57
  58 ArithmeticExpression::ArithmeticExpression(const Expression::Ptr &op1,
  59                                            const AtomicMathematician::Operator op,
  60                                            const Expression::Ptr &op2) : PairContainer(op1, op2)
  61                                                                        , m_op(op)
  62                                                                        , m_isCompat(false)
  63 {
  64 }
  65
  66 Item ArithmeticExpression::evaluateSingleton(const DynamicContext::Ptr &context) const
  67 {
  68     const Item op1(m_operand1->evaluateSingleton(context));
  69     if(!op1)
  70         return Item();
  71
  72     const Item op2(m_operand2->evaluateSingleton(context));
  73     if(!op2)
  74         return Item();
  75
  76     return flexiblyCalculate(op1, m_op, op2, m_mather, context, this,
  77                              ReportContext::XPTY0004, m_isCompat);
  78 }
  79
  80 /**
  81  * Since ArithmeticExpression::flexiblyCalculate() creates Expression instances
  82  * at runtime, we have the problem of having SourceLocationReflections for them
  83  * in the case that we run into a runtime error, since the locations are always
  84  * located at compile time.
  85  *
  86  * This class simply delegates the reflection over to an existing expression.
  87  *
  88  * I only managed to trigger this with "current() + 1", where current()
  89  * evaluates to an invalid representation for @c xs:double.
  90  *
  91  * @since 4.5
  92  * @author Frans Englich <frans.englich@nokia.com>
  93  */
  94 class DelegatingReflectionExpression : public Literal
  95 {
  96 public:
  97     DelegatingReflectionExpression(const Item &item,
  98                                    const SourceLocationReflection *const reflection) : Literal(item)
  99                                                                                      , m_reflection(reflection)
 100     {
 101     }
 102
 103     virtual const SourceLocationReflection *actualReflection() const
 104     {
 105         return m_reflection;
 106     }
 107
 108 private:
 109     const SourceLocationReflection *const m_reflection;
 110 };
 111
 112 Item ArithmeticExpression::flexiblyCalculate(const Item &op1,
 113                                              const AtomicMathematician::Operator op,
 114                                              const Item &op2,
 115                                              const AtomicMathematician::Ptr &mather,
 116                                              const DynamicContext::Ptr &context,
 117                                              const SourceLocationReflection *const reflection,
 118                                              const ReportContext::ErrorCode code,
 119                                              const bool isCompat)
 120 {
 121     if(mather)
 122         return mather->calculate(op1, op, op2, context);
 123
 124     /* This is a very heavy code path. */
 125     Expression::Ptr a1(new DelegatingReflectionExpression(op1, reflection));
 126     Expression::Ptr a2(new DelegatingReflectionExpression(op2, reflection));
 127
 128     const AtomicMathematician::Ptr ingela(fetchMathematician(a1, a2, op, true, context, reflection, code, isCompat));
 129
 130     return ingela->calculate(a1->evaluateSingleton(context),
 131                              op,
 132                              a2->evaluateSingleton(context),
 133                              context);
 134 }
 135
 136 Expression::Ptr ArithmeticExpression::typeCheck(const StaticContext::Ptr &context,
 137                                                 const SequenceType::Ptr &reqType)
 138 {
 139     m_isCompat = context->compatModeEnabled();
 140
 141     const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
 142     const ItemType::Ptr t1(m_operand1->staticType()->itemType());
 143     const ItemType::Ptr t2(m_operand2->staticType()->itemType());
 144
 145     if(*CommonSequenceTypes::Empty == *t1 ||
 146        *CommonSequenceTypes::Empty == *t2)
 147     {
 148         return EmptySequence::create(this, context);
 149     }
 150
 151     if(*BuiltinTypes::xsAnyAtomicType == *t1    ||
 152        *BuiltinTypes::xsAnyAtomicType == *t2    ||
 153        *BuiltinTypes::numeric == *t1            ||
 154        *BuiltinTypes::numeric == *t2)
 155     {
 156         /* The static type of (at least) one of the operands could not
 157          * be narrowed further than xs:anyAtomicType, so we do the operator
 158          * lookup at runtime. */
 159         return me;
 160     }
 161
 162     m_mather = fetchMathematician(m_operand1, m_operand2, m_op, true, context, this,
 163                                   ReportContext::XPTY0004, m_isCompat);
 164
 165     return me;
 166 }
 167
 168 AtomicMathematician::Ptr
 169 ArithmeticExpression::fetchMathematician(Expression::Ptr &op1,
 170                                          Expression::Ptr &op2,
 171                                          const AtomicMathematician::Operator op,
 172                                          const bool issueError,
 173                                          const ReportContext::Ptr &context,
 174                                          const SourceLocationReflection *const reflection,
 175                                          const ReportContext::ErrorCode code,
 176                                          const bool isCompat)
 177 {
 178     ItemType::Ptr t1(op1->staticType()->itemType());
 179     ItemType::Ptr t2(op2->staticType()->itemType());
 180
 181     if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1)
 182        || (isCompat && (BuiltinTypes::xsString->xdtTypeMatches(t1)
 183                         || BuiltinTypes::xsDecimal->xdtTypeMatches(t1))))
 184     {
 185         op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble));
 186         /* The types might have changed, reload. */
 187         t1 = op1->staticType()->itemType();
 188     }
 189
 190     if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2)
 191        || (isCompat && (BuiltinTypes::xsString->xdtTypeMatches(t1)
 192                         || BuiltinTypes::xsDecimal->xdtTypeMatches(t1))))
 193     {
 194         op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble));
 195         /* The types might have changed, reload. */
 196         t2 = op2->staticType()->itemType();
 197     }
 198
 199     const AtomicMathematicianLocator::Ptr locator
 200         (static_cast<const AtomicType *>(t1.data())->mathematicianLocator());
 201
 202     if(!locator)
 203     {
 204         if(!issueError)
 205             return AtomicMathematician::Ptr();
 206
 207         context->error(QtXmlPatterns::tr(
 208                        "Operator %1 cannot be used on type %2.")
 209                        .arg(formatKeyword(AtomicMathematician::displayName(op)))
 210                        .arg(formatType(context->namePool(), t1)),
 211                        code, reflection);
 212         return AtomicMathematician::Ptr();
 213     }
 214
 215     const AtomicMathematician::Ptr comp
 216         (static_cast<const AtomicType *>(t2.data())->accept(locator, op, reflection));
 217
 218     if(comp)
 219         return comp;
 220
 221     if(!issueError)
 222         return AtomicMathematician::Ptr();
 223
 224     context->error(QtXmlPatterns::tr("Operator %1 cannot be used on "
 225                                      "atomic values of type %2 and %3.")
 226                    .arg(formatKeyword(AtomicMathematician::displayName(op)))
 227                    .arg(formatType(context->namePool(), t1))
 228                    .arg(formatType(context->namePool(), t2)),
 229                    code, reflection);
 230     return AtomicMathematician::Ptr();
 231 }
 232
 233 SequenceType::Ptr ArithmeticExpression::staticType() const
 234 {
 235     Cardinality card;
 236
 237     /* These variables are important because they ensure staticType() only
 238      * gets called once from this function. Before, this lead to strange
 239      * semi-infinite recursion involving many arithmetic expressions. */
 240     const SequenceType::Ptr st1(m_operand1->staticType());
 241     const SequenceType::Ptr st2(m_operand2->staticType());
 242
 243     if(st1->cardinality().allowsEmpty() ||
 244        st2->cardinality().allowsEmpty())
 245     {
 246         card = Cardinality::zeroOrOne();
 247     }
 248     else
 249         card = Cardinality::exactlyOne();
 250
 251     if(m_op == AtomicMathematician::IDiv)
 252         return makeGenericSequenceType(BuiltinTypes::xsInteger, card);
 253
 254     const ItemType::Ptr t1(st1->itemType());
 255     const ItemType::Ptr t2(st2->itemType());
 256     ItemType::Ptr returnType;
 257
 258     /* Please, make this beautiful? */
 259     if(BuiltinTypes::xsTime->xdtTypeMatches(t1) ||
 260        BuiltinTypes::xsDate->xdtTypeMatches(t1) ||
 261        BuiltinTypes::xsDateTime->xdtTypeMatches(t1))
 262     {
 263         if(BuiltinTypes::xsDuration->xdtTypeMatches(t2))
 264             returnType = t1;
 265         else
 266             returnType = BuiltinTypes::xsDayTimeDuration;
 267     }
 268     else if(BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t1))
 269     {
 270         if(m_op == AtomicMathematician::Div &&
 271            BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t2))
 272         {
 273             returnType = BuiltinTypes::xsDecimal;
 274         }
 275         else if(BuiltinTypes::numeric->xdtTypeMatches(t2))
 276             returnType = BuiltinTypes::xsYearMonthDuration;
 277         else
 278             returnType = t2;
 279     }
 280     else if(BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t2))
 281     {
 282         returnType = BuiltinTypes::xsYearMonthDuration;
 283     }
 284     else if(BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t1))
 285     {
 286         if(m_op == AtomicMathematician::Div &&
 287            BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t2))
 288         {
 289             returnType = BuiltinTypes::xsDecimal;
 290         }
 291         else if(BuiltinTypes::numeric->xdtTypeMatches(t2))
 292             returnType = BuiltinTypes::xsDayTimeDuration;
 293         else
 294             returnType = t2;
 295     }
 296     else if(BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t2))
 297     {
 298         returnType = BuiltinTypes::xsDayTimeDuration;
 299     }
 300     else if(BuiltinTypes::xsDouble->xdtTypeMatches(t1) ||
 301             BuiltinTypes::xsDouble->xdtTypeMatches(t2))
 302     {
 303         returnType = BuiltinTypes::xsDouble;
 304     }
 305     else if(BuiltinTypes::xsFloat->xdtTypeMatches(t1) ||
 306             BuiltinTypes::xsFloat->xdtTypeMatches(t2))
 307     {
 308         if(m_isCompat)
 309             returnType = BuiltinTypes::xsFloat;
 310         else
 311             returnType = BuiltinTypes::xsDouble;
 312     }
 313     else if(BuiltinTypes::xsInteger->xdtTypeMatches(t1) &&
 314             BuiltinTypes::xsInteger->xdtTypeMatches(t2))
 315     {
 316         if(m_isCompat)
 317             returnType = BuiltinTypes::xsDouble;
 318         else
 319         {
 320             /* "A div B  numeric  numeric  op:numeric-divide(A, B)
 321              * numeric; but xs:decimal if both operands are xs:integer" */
 322             if(m_op == AtomicMathematician::Div)
 323                 returnType = BuiltinTypes::xsDecimal;
 324             else
 325                 returnType = BuiltinTypes::xsInteger;
 326         }
 327     }
 328     else if(m_isCompat && (BuiltinTypes::xsInteger->xdtTypeMatches(t1) &&
 329                            BuiltinTypes::xsInteger->xdtTypeMatches(t2)))
 330     {
 331         returnType = BuiltinTypes::xsDouble;
 332     }
 333     else
 334     {
 335         /* If typeCheck() has been called, our operands conform to expectedOperandTypes(), and
 336          * the types are hence either xs:decimals, or xs:anyAtomicType(meaning the static type could
 337          * not be inferred), or empty-sequence(). So we use the union of the two types. The combinations
 338          * could also be wrong.*/
 339         returnType = t1 | t2;
 340
 341         /* However, if we're called before typeCheck(), we could potentially have nodes, so we need to make
 342          * sure that the type is at least atomic. */
 343         if(!BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(returnType))
 344             returnType = BuiltinTypes::xsAnyAtomicType;
 345     }
 346
 347     return makeGenericSequenceType(returnType, card);
 348 }
 349
 350 SequenceType::List ArithmeticExpression::expectedOperandTypes() const
 351 {
 352     SequenceType::List result;
 353     result.append(CommonSequenceTypes::ZeroOrOneAtomicType);
 354     result.append(CommonSequenceTypes::ZeroOrOneAtomicType);
 355     return result;
 356 }
 357
 358 ExpressionVisitorResult::Ptr ArithmeticExpression::accept(const ExpressionVisitor::Ptr &visitor) const
 359 {
 360     return visitor->visit(this);
 361 }
 362
 363 QT_END_NAMESPACE