Qt 4.8
Public Functions | Private Types | Properties | List of all members
QPatternist::UntypedAtomicConverter Class Reference

Casts every item in a sequence obtained from evaluating an Expression, to a requested atomic type. More...

#include <quntypedatomicconverter_p.h>

Inheritance diagram for QPatternist::UntypedAtomicConverter:
QPatternist::SingleContainer QPatternist::CastingPlatform< UntypedAtomicConverter, true > QPatternist::Expression QSharedData QPatternist::CppCastingHelper< Expression > QPatternist::SourceLocationReflection QPatternist::ArgumentConverter

Public Functions

virtual ExpressionVisitorResult::Ptr accept (const ExpressionVisitor::Ptr &visitor) const
 
virtual const SourceLocationReflectionactualReflection () const
 Returns this. More...
 
virtual Item::Iterator::Ptr evaluateSequence (const DynamicContext::Ptr &) const
 
virtual Item evaluateSingleton (const DynamicContext::Ptr &) const
 
virtual SequenceType::List expectedOperandTypes () const
 
Item mapToItem (const Item &item, const DynamicContext::Ptr &context) const
 
virtual SequenceType::Ptr staticType () const
 
ItemType::Ptr targetType () const
 
virtual Expression::Ptr typeCheck (const StaticContext::Ptr &context, const SequenceType::Ptr &reqType)
 
 UntypedAtomicConverter (const Expression::Ptr &operand, const ItemType::Ptr &reqType, const ReportContext::ErrorCode code=ReportContext::FORG0001)
 
- Public Functions inherited from QPatternist::SingleContainer
virtual bool compressOperands (const StaticContext::Ptr &)
 
virtual Expression::List operands () const
 
virtual void setOperands (const Expression::List &operands)
 
- Public Functions inherited from QPatternist::Expression
virtual void announceFocusType (const ItemType::Ptr &itemType)
 
virtual Expression::Ptr compress (const StaticContext::Ptr &context)
 
Properties deepProperties () const
 Computes the union of properties for this Expression and all its descending children. More...
 
virtual Properties dependencies () const
 
virtual QString description () const
 
virtual bool evaluateEBV (const DynamicContext::Ptr &context) const
 
virtual void evaluateToSequenceReceiver (const DynamicContext::Ptr &context) const
 
virtual ItemType::Ptr expectedContextItemType () const
 
 Expression ()
 
bool has (const Property prop) const
 
bool hasDependency (const Property prop) const
 
virtual ID id () const
 
bool is (const ID id) const
 
bool isEvaluated () const
 
virtual ItemType::Ptr newFocusType () const
 
virtual QList< QExplicitlySharedDataPointer< OptimizationPass > > optimizationPasses () const
 
virtual PatternPriority patternPriority () const
 
virtual Properties properties () const
 
const Expression::Ptrrewrite (const Expression::Ptr &to, const StaticContext::Ptr &context) const
 Rewrites this Expression to to, and return to. More...
 
virtual ~Expression ()
 
- Public Functions inherited from QSharedData
 QSharedData ()
 Constructs a QSharedData object with a reference count of 0. More...
 
 QSharedData (const QSharedData &)
 Constructs a QSharedData object with reference count 0. More...
 
- Public Functions inherited from QPatternist::CppCastingHelper< Expression >
const TCastTarget * as () const
 
TCastTarget * as ()
 
- Public Functions inherited from QPatternist::SourceLocationReflection
virtual QSourceLocation sourceLocation () const
 
 SourceLocationReflection ()
 
virtual ~SourceLocationReflection ()
 

Private Types

typedef QExplicitlySharedDataPointer< const UntypedAtomicConverterConstPtr
 

Properties

const ItemType::Ptr m_reqType
 

Additional Inherited Members

- Public Types inherited from QPatternist::Expression
typedef QExplicitlySharedDataPointer< const ExpressionConstPtr
 A smart pointer wrapping const Expression instances. More...
 
enum  ID {
  IDBooleanValue = 1, IDCountFN, IDEmptyFN, IDExistsFN,
  IDExpressionSequence, IDGeneralComparison, IDIfThenClause, IDIgnorableExpression,
  IDIntegerValue, IDPositionFN, IDStringValue, IDValueComparison,
  IDRangeVariableReference, IDContextItem, IDUserFunctionCallsite, IDExpressionVariableReference,
  IDAttributeConstructor, IDUpperCaseFN, IDLowerCaseFN, IDFirstItemPredicate,
  IDEmptySequence, IDReturnOrderBy, IDLetClause, IDForClause,
  IDPath, IDNamespaceConstructor, IDArgumentReference, IDGenericPredicate,
  IDAxisStep, IDFloat, IDCombineNodes, IDUnresolvedVariableReference,
  IDCardinalityVerifier
}
 
typedef QList< Expression::PtrList
 
typedef QFlags< PropertyProperties
 
enum  Property {
  UseContextItem = 1, DisableElimination = 1 << 1, IsEvaluated = 1 << 2, DisableTypingDeduction = 1 << 3,
  EmptynessFollowsChild = 1 << 4, RewriteToEmptyOnEmpty = 1 << 5, RequiresFocus = 1 << 6, AffectsOrderOnly = 1 << 7,
  RequiresContextItem = (1 << 8) | RequiresFocus, CreatesFocusForLast = 1 << 9, LastOperandIsCollation = 1 << 10, DependsOnLocalVariable = (1 << 11) | DisableElimination,
  EvaluationCacheRedundant = (1 << 12), IsNodeConstructor = 1 << 13, RequiresCurrentItem = 1 << 14
}
 
typedef QExplicitlySharedDataPointer< ExpressionPtr
 A smart pointer wrapping mutable Expression instances. More...
 
typedef ::QAbstractXmlForwardIterator< Expression::PtrQAbstractXmlForwardIterator
 
typedef QVector< Expression::PtrVector
 
- Static Public Functions inherited from QPatternist::Expression
static void rewrite (Expression::Ptr &old, const Expression::Ptr &New, const StaticContext::Ptr &context)
 
- Public Variables inherited from QSharedData
QAtomicInt ref
 
- Protected Functions inherited from QPatternist::SingleContainer
 SingleContainer (const Expression::Ptr &operand)
 
- Protected Functions inherited from QPatternist::Expression
void typeCheckOperands (const StaticContext::Ptr &context)
 
- Protected Functions inherited from QPatternist::CppCastingHelper< Expression >
 CppCastingHelper ()
 
- Protected Functions inherited from QPatternist::CastingPlatform< UntypedAtomicConverter, true >
Item cast (const Item &sourceValue, const ReportContext::Ptr &context) const
 
 CastingPlatform (const ReportContext::ErrorCode code=ReportContext::FORG0001)
 
void checkTargetType (const ReportContext::Ptr &context) const
 
bool prepareCasting (const ReportContext::Ptr &context, const ItemType::Ptr &sourceType)
 
- Protected Variables inherited from QPatternist::SingleContainer
Expression::Ptr m_operand
 

Detailed Description

Casts every item in a sequence obtained from evaluating an Expression, to a requested atomic type.

The atomic values it casts from are instances of xs:untypedAtomic(hence the name). Typically, the items are from an Atomizer. UntypedAtomicConverter implements the automatic conversion which typically is activated when XPath is handling untyped data.

See also
XML Path Language (XPath) 2.0, 3.1.5 Function Calls, in particular the Function Conversion Rules
Author
Frans Englich frans.nosp@m..eng.nosp@m.lich@.nosp@m.noki.nosp@m.a.com

Definition at line 80 of file quntypedatomicconverter_p.h.

Typedefs

◆ ConstPtr

Definition at line 113 of file quntypedatomicconverter_p.h.

Constructors and Destructors

◆ UntypedAtomicConverter()

UntypedAtomicConverter::UntypedAtomicConverter ( const Expression::Ptr operand,
const ItemType::Ptr reqType,
const ReportContext::ErrorCode  code = ReportContext::FORG0001 
)

Definition at line 53 of file quntypedatomicconverter.cpp.

55  : SingleContainer(operand)
57  , m_reqType(reqType)
58 {
59  Q_ASSERT(reqType);
60 }
#define Q_ASSERT(cond)
Definition: qglobal.h:1823
SingleContainer(const Expression::Ptr &operand)

Functions

◆ accept()

ExpressionVisitorResult::Ptr UntypedAtomicConverter::accept ( const ExpressionVisitor::Ptr visitor) const
virtual

Implements QPatternist::Expression.

Reimplemented in QPatternist::ArgumentConverter.

Definition at line 103 of file quntypedatomicconverter.cpp.

104 {
105  return visitor->visit(this);
106 }

◆ actualReflection()

const SourceLocationReflection * UntypedAtomicConverter::actualReflection ( ) const
virtual

Returns this.

Reimplemented from QPatternist::Expression.

Definition at line 108 of file quntypedatomicconverter.cpp.

Referenced by targetType().

109 {
110  return m_operand.data();
111 }
T * data() const
Returns a pointer to the shared data object.
Definition: qshareddata.h:145

◆ evaluateSequence()

Item::Iterator::Ptr UntypedAtomicConverter::evaluateSequence ( const DynamicContext::Ptr context) const
virtual

Evaluate this Expression by iterating over it. This is a central function for evaluating expressions.

Expressions must always always return a valid QAbstractXmlForwardIterator and may never return 0. If an empty result is of interest to be returned, the EmptyIterator should be returned.

The default implementation returns a SingletonIterator over the item returned from evaluateSingleton().

Note
This function may raise an exception when calling, not only when QAbstractXmlForwardIterator::next() is called on the return value. This is because in some cases evaluateSingleton() is called directly.

Reimplemented from QPatternist::Expression.

Reimplemented in QPatternist::ArgumentConverter.

Definition at line 62 of file quntypedatomicconverter.cpp.

63 {
64  return makeItemMappingIterator<Item>(ConstPtr(this),
65  m_operand->evaluateSequence(context),
66  context);
67 }
QExplicitlySharedDataPointer< const UntypedAtomicConverter > ConstPtr
virtual Item::Iterator::Ptr evaluateSequence(const DynamicContext::Ptr &context) const

◆ evaluateSingleton()

Item UntypedAtomicConverter::evaluateSingleton ( const DynamicContext::Ptr context) const
virtual

Reimplemented from QPatternist::Expression.

Reimplemented in QPatternist::ArgumentConverter.

Definition at line 69 of file quntypedatomicconverter.cpp.

70 {
71  const Item item(m_operand->evaluateSingleton(context));
72 
73  if(item)
74  return cast(item, context);
75  else /* Empty is allowed. UntypedAtomicConverter doesn't care about cardinality. */
76  return Item();
77 }
Item cast(const Item &sourceValue, const ReportContext::Ptr &context) const
Represents an item in the XPath 2.0 Data Model.
Definition: qitem_p.h:182
virtual Item evaluateSingleton(const DynamicContext::Ptr &context) const

◆ expectedOperandTypes()

SequenceType::List UntypedAtomicConverter::expectedOperandTypes ( ) const
virtual

Returns a list of Sequence Types, describing the type of each of the expression's operands. Hence, this function has a relationship to the operands() function:

- The lengths of the lists returned by expectedOperandTypes()
and operands() should always be equal in length, since one
cannot describe the type of a non-existent operand(and all
operands must have type information).
- A significant difference between the two functions is that while
the type of objects in the list returned by operands() may vary
between compilations/static context, simply because the particular
Expression is part of different XPath expressions, the
types in the list returned by expectedOperandTypes is always the same
since the function/operator signature never changes.

This function should not be confused with staticType(), which returns the static type of the expression itself, not its operands. The function call is an expression where this is clear: the type of the return value is not the same as the arguments' types. The static type of the operands supplied to the expression can be determined via the staticType() function of the instances returned by operands().

If the expression has no operands, an empty list should be returned.

Implements QPatternist::Expression.

Reimplemented in QPatternist::ArgumentConverter.

Definition at line 90 of file quntypedatomicconverter.cpp.

91 {
92  SequenceType::List result;
94  return result;
95 }
void append(const T &t)
Inserts value at the end of the list.
Definition: qlist.h:507
static const SequenceType::Ptr ZeroOrMoreAtomicTypes
The QList class is a template class that provides lists.
Definition: qdatastream.h:62

◆ mapToItem()

Item QPatternist::UntypedAtomicConverter::mapToItem ( const Item item,
const DynamicContext::Ptr context 
) const
inline

Definition at line 117 of file quntypedatomicconverter_p.h.

Referenced by QPatternist::ArgumentConverter::evaluateSingleton().

118  {
119  return cast(item, context);
120  }
Item cast(const Item &sourceValue, const ReportContext::Ptr &context) const

◆ staticType()

SequenceType::Ptr UntypedAtomicConverter::staticType ( ) const
virtual
Returns
the static type of this Expression. For example, an 'and' expression have as static type xs:boolean

Implements QPatternist::Expression.

Reimplemented in QPatternist::ArgumentConverter.

Definition at line 97 of file quntypedatomicconverter.cpp.

98 {
99  return makeGenericSequenceType(m_reqType,
101 }
virtual Cardinality cardinality() const =0
virtual SequenceType::Ptr staticType() const =0

◆ targetType()

ItemType::Ptr QPatternist::UntypedAtomicConverter::targetType ( ) const
inline

Definition at line 105 of file quntypedatomicconverter_p.h.

106  {
107  return m_reqType;
108  }

◆ typeCheck()

Expression::Ptr UntypedAtomicConverter::typeCheck ( const StaticContext::Ptr context,
const SequenceType::Ptr reqType 
)
virtual

Overridden to call CastingPlatform::typeCheck()

Reimplemented from QPatternist::Expression.

Definition at line 79 of file quntypedatomicconverter.cpp.

81 {
82  const Expression::Ptr me(SingleContainer::typeCheck(context, reqType));
83 
84  /* Let the CastingPlatform look up its AtomicCaster. */
86 
87  return me;
88 }
virtual Expression::Ptr typeCheck(const StaticContext::Ptr &context, const SequenceType::Ptr &reqType)
Definition: qexpression.cpp:70
bool prepareCasting(const ReportContext::Ptr &context, const ItemType::Ptr &sourceType)
virtual SequenceType::Ptr staticType() const =0
virtual ItemType::Ptr itemType() const =0

Properties

◆ m_reqType

const ItemType::Ptr QPatternist::UntypedAtomicConverter::m_reqType
private

Definition at line 114 of file quntypedatomicconverter_p.h.

Referenced by staticType(), and targetType().


The documentation for this class was generated from the following files: