A reference to an external variable. More...

#include <qexternalvariablereference_p.h>

Inheritance diagram for QPatternist::ExternalVariableReference:

Public Functions
virtual ExpressionVisitorResult::Ptr	accept (const ExpressionVisitor::Ptr &visitor) const

virtual bool	evaluateEBV (const DynamicContext::Ptr &context) const

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

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

	ExternalVariableReference (const QXmlName &name, const SequenceType::Ptr &type)

virtual Expression::Properties	properties () const

virtual SequenceType::Ptr	staticType () const

Public Functions inherited from QPatternist::EmptyContainer
virtual Expression::List	operands () const

virtual void	setOperands (const Expression::List &)

Public Functions inherited from QPatternist::Expression
virtual const SourceLocationReflection *	actualReflection () const
	Returns `this`. More...

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 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

const Expression::Ptr &	rewrite (const Expression::Ptr &to, const StaticContext::Ptr &context) const
	Rewrites this Expression to `to`, and return `to`. More...

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

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 ()

Properties
const QXmlName	m_name

const SequenceType::Ptr	m_seqType

Additional Inherited Members
Public Types inherited from QPatternist::Expression
typedef QExplicitlySharedDataPointer< const Expression >	ConstPtr
	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::Ptr >	List

typedef QFlags< Property >	Properties

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< Expression >	Ptr
	A smart pointer wrapping mutable Expression instances. More...

typedef ::QAbstractXmlForwardIterator< Expression::Ptr >	QAbstractXmlForwardIterator

typedef QVector< Expression::Ptr >	Vector

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::EmptyContainer
virtual bool	compressOperands (const StaticContext::Ptr &context)

virtual SequenceType::List	expectedOperandTypes () const

Protected Functions inherited from QPatternist::Expression
void	typeCheckOperands (const StaticContext::Ptr &context)

Protected Functions inherited from QPatternist::CppCastingHelper< Expression >
	CppCastingHelper ()

Detailed Description

A reference to an external variable.

ExternalVariableReference does not sub-class VariableReference, because it works differently from how sub-classes of VariableReference do. This class uses DynamicContext::externalVariableLoader() for retrieving its value, while a VariableReference sub-class uses slots in the DynamicContext.

Author: Frans Englich frans.nosp@m..eng.nosp@m.lich@.nosp@m.noki.nosp@m.a.com

Definition at line 74 of file qexternalvariablereference_p.h.

Constructors and Destructors

◆ ExternalVariableReference()

ExternalVariableReference::ExternalVariableReference	(	const QXmlName &	name,
		const SequenceType::Ptr &	type
	)

Definition at line 49 of file qexternalvariablereference.cpp.

                                                                                   : m_name(name),
                                                                                       m_seqType(type)
 {
     Q_ASSERT(!m_name.isNull());
     Q_ASSERT(m_seqType);
 }

Functions

◆ accept()

ExpressionVisitorResult::Ptr ExternalVariableReference::accept ( const ExpressionVisitor::Ptr & visitor ) const

virtual

Implements QPatternist::Expression.

Definition at line 83 of file qexternalvariablereference.cpp.

 {
     return visitor->visit(this);
 }

◆ evaluateEBV()

bool ExternalVariableReference::evaluateEBV ( const DynamicContext::Ptr & context ) const

virtual

Determines the Effective Boolean Value of the expression.

The Effective Boolean Value of a value is not necessarily the same as converting the value to a new value of type xs:boolean.

Note that this function cannot return the empty sequence, evaluateSingleton() must be overridden in order to be able to do that.

The default implementation results in a type error. Hence, this function must be overridden if such behavior is not of interest.

See also: XML Path Language (XPath) 2.0, 2.4.3 Effective Boolean Value

Reimplemented from QPatternist::Expression.

Definition at line 68 of file qexternalvariablereference.cpp.

 {
     return context->externalVariableLoader()->evaluateEBV(m_name, context);
 }

◆ evaluateSequence()

Item::Iterator::Ptr ExternalVariableReference::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.

Definition at line 57 of file qexternalvariablereference.cpp.

 {
     Q_ASSERT(context->externalVariableLoader());
     return context->externalVariableLoader()->evaluateSequence(m_name, context);
 }

◆ evaluateSingleton()

Item ExternalVariableReference::evaluateSingleton ( const DynamicContext::Ptr & context ) const

virtual

Reimplemented from QPatternist::Expression.

Definition at line 63 of file qexternalvariablereference.cpp.

 {
     return context->externalVariableLoader()->evaluateSingleton(m_name, context);
 }

◆ properties()

Expression::Properties ExternalVariableReference::properties ( ) const

virtual

Returns: always DisableElimination

Reimplemented from QPatternist::Expression.

Definition at line 78 of file qexternalvariablereference.cpp.

 {
     return DisableElimination;
 }

◆ staticType()

SequenceType::Ptr ExternalVariableReference::staticType ( ) const

virtual

Returns: the static type of this Expression. For example, an 'and' expression have as static type xs:boolean

Implements QPatternist::Expression.

Definition at line 73 of file qexternalvariablereference.cpp.

 {
     return m_seqType;
 }

Properties

◆ m_name

const QXmlName QPatternist::ExternalVariableReference::m_name

private

Definition at line 94 of file qexternalvariablereference_p.h.

Referenced by evaluateEBV(), evaluateSequence(), evaluateSingleton(), and ExternalVariableReference().

◆ m_seqType

const SequenceType::Ptr QPatternist::ExternalVariableReference::m_seqType

private

Definition at line 95 of file qexternalvariablereference_p.h.

Referenced by ExternalVariableReference(), and staticType().

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

/src/xmlpatterns/expr/qexternalvariablereference_p.h
/src/xmlpatterns/expr/qexternalvariablereference.cpp

Public Functions

Properties

Additional Inherited Members

Detailed Description

Constructors and Destructors

◆ ExternalVariableReference()

Functions

◆ accept()

◆ evaluateEBV()

◆ evaluateSequence()

◆ evaluateSingleton()

◆ properties()

◆ staticType()

Properties

◆ m_name

◆ m_seqType