Qt 4.8
qinstanceof.cpp
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41 
42 #include "qboolean_p.h"
43 #include "qcommonsequencetypes_p.h"
44 #include "qcommonvalues_p.h"
45 #include "qliteral_p.h"
46 
47 #include "qinstanceof_p.h"
48 
50 
51 using namespace QPatternist;
52 
54  const SequenceType::Ptr &tType) : SingleContainer(operand)
55  , m_targetType(tType)
56 {
58 }
59 
60 bool InstanceOf::evaluateEBV(const DynamicContext::Ptr &context) const
61 {
63  Item item(it->next());
64  unsigned int count = 1;
65 
66  if(!item)
68 
69  do
70  {
71  if(!m_targetType->itemType()->itemMatches(item))
72  return false;
73 
74  if(count == 2 && !m_targetType->cardinality().allowsMany())
75  return false;
76 
77  item = it->next();
78  ++count;
79  } while(item);
80 
81  return true;
82 }
83 
85 {
86  const Expression::Ptr me(SingleContainer::compress(context));
87 
88  if(me != this || m_operand->has(DisableTypingDeduction))
89  return me;
90 
91  const SequenceType::Ptr opType(m_operand->staticType());
93  const ItemType::Ptr operandType(opType->itemType());
94 
95  if(m_targetType->cardinality().isMatch(opType->cardinality()))
96  {
97  if(*operandType == *CommonSequenceTypes::Empty || targetType->xdtTypeMatches(operandType))
98  return wrapLiteral(CommonValues::BooleanTrue, context, this);
99  else if(!operandType->xdtTypeMatches(targetType))
100  return wrapLiteral(CommonValues::BooleanFalse, context, this);
101  }
102  /* Optimization: rule out the case where instance of will always fail. */
103 
104  return me;
105 }
106 
108 {
109  return m_targetType;
110 }
111 
113 {
115 }
116 
118 {
119  SequenceType::List result;
121  return result;
122 }
123 
125 {
126  return visitor->visit(this);
127 }
128 
#define QT_END_NAMESPACE
This macro expands to.
Definition: qglobal.h:90
virtual SequenceType::List expectedOperandTypes() const
static const AtomicValue::Ptr BooleanTrue
static const SequenceType::Ptr ZeroOrMoreItems
#define it(className, varName)
virtual bool itemMatches(const Item &item) const =0
virtual Expression::Ptr compress(const StaticContext::Ptr &context)
Definition: qinstanceof.cpp:84
InstanceOf(const Expression::Ptr &operand, const SequenceType::Ptr &targetType)
Definition: qinstanceof.cpp:53
virtual ExpressionVisitorResult::Ptr accept(const ExpressionVisitor::Ptr &visitor) const
#define Q_ASSERT(cond)
Definition: qglobal.h:1823
bool has(const Property prop) const
virtual Expression::Ptr compress(const StaticContext::Ptr &context)
void append(const T &t)
Inserts value at the end of the list.
Definition: qlist.h:507
#define QT_BEGIN_NAMESPACE
This macro expands to.
Definition: qglobal.h:89
The namespace for the internal API of QtXmlPatterns.
virtual bool evaluateEBV(const DynamicContext::Ptr &) const
Definition: qinstanceof.cpp:60
virtual Cardinality cardinality() const =0
virtual SequenceType::Ptr staticType() const
static const SequenceType::Ptr ExactlyOneBoolean
virtual SequenceType::Ptr staticType() const =0
static const EmptySequenceType::Ptr Empty
Represents an item in the XPath 2.0 Data Model.
Definition: qitem_p.h:182
SequenceType::Ptr targetType() const
virtual ItemType::Ptr itemType() const =0
bool isMatch(const Cardinality &other) const
static const AtomicValue::Ptr BooleanFalse
const SequenceType::Ptr m_targetType
Definition: qinstanceof_p.h:93
The QList class is a template class that provides lists.
Definition: qdatastream.h:62
virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const
Base class for expressions that has exactly one operand.