Compile time only AST-node which is a marker for variable references whose declaration has not yet appeared in the source code. More...

#include <qunresolvedvariablereference_p.h>

Inheritance diagram for QPatternist::UnresolvedVariableReference:

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

void	bindTo (const Expression::Ptr &body)

virtual SequenceType::List	expectedOperandTypes () const

virtual ID	id () const

Expression::Ptr	replacement () const

virtual SequenceType::Ptr	staticType () const

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

	UnresolvedVariableReference (const QXmlName &name)

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 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

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

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::Ptr &	rewrite (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 ()

Properties
const QXmlName	m_name

Expression::Ptr	m_replacement

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)

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

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

Detailed Description

Compile time only AST-node which is a marker for variable references whose declaration has not yet appeared in the source code.

This can not appear in XQuery, but can in XSL-T.

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

Since: 4.5

Definition at line 73 of file qunresolvedvariablereference_p.h.

Constructors and Destructors

◆ UnresolvedVariableReference()

UnresolvedVariableReference::UnresolvedVariableReference ( const QXmlName & name )

Definition at line 50 of file qunresolvedvariablereference.cpp.

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

Functions

◆ accept()

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

virtual

Implements QPatternist::Expression.

Definition at line 81 of file qunresolvedvariablereference.cpp.

 {
     return visitor->visit(this);
 }

◆ bindTo()

void QPatternist::UnresolvedVariableReference::bindTo ( const Expression::Ptr & body )

inline

Definition at line 94 of file qunresolvedvariablereference_p.h.

     {
         Q_ASSERT(body);
         m_replacement = body;
     }

◆ expectedOperandTypes()

SequenceType::List UnresolvedVariableReference::expectedOperandTypes ( ) const

virtual

Returns: always an empty list since it has no operands.

Reimplemented from QPatternist::EmptyContainer.

Definition at line 76 of file qunresolvedvariablereference.cpp.

 {
     return SequenceType::List();
 }

◆ id()

Expression::ID UnresolvedVariableReference::id ( ) const

virtual

This property, which has no setter, returns an enum value that uniquely identifies this Expression. Patternist makes no use of C++'s dynamic_cast feature, but uses this polymorphic function instead.

Returns: always IgnorableExpression.

Reimplemented from QPatternist::Expression.

Definition at line 86 of file qunresolvedvariablereference.cpp.

 {
     return IDUnresolvedVariableReference;
 }

◆ replacement()

Expression::Ptr QPatternist::UnresolvedVariableReference::replacement ( ) const

inline

Definition at line 100 of file qunresolvedvariablereference_p.h.

Referenced by QPatternist::checkVariableCircularity().

     {
         Q_ASSERT(m_replacement);
         return m_replacement;
     }

◆ staticType()

SequenceType::Ptr UnresolvedVariableReference::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 67 of file qunresolvedvariablereference.cpp.

 {
     /* We may be called by xmlpatternsview before the typeCheck() stage. */
     if(m_replacement)
         return m_replacement->staticType();
     else
         return CommonSequenceTypes::ZeroOrMoreItems;
 }

◆ typeCheck()

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

virtual

This implementation guarantees to never rewrite away this Expression, but at most rewrite it as a child of another expression(that presumably have a type checking role). It is therefore always safe to override this function and call this implementation and not worry about that this Expression becomes deleted.

Many Expressions override typeCheck() and performs optimizations, as opposed to doing it in the compress() stage. This is due to that the design of those Expressions often are tied to that certain simplifications are done at the typeCheck() stage of the compilation process or that it in some other way is related to what the typeCheck() do. Also, the earlier the AST can be simplified, the better the chances are for subsequent optimizations.

It is important that the super class's typeCheck() is called before doing any custom type checking, since the call can change the children(notably, the childrens' static types). For example, if the Expression, MyExpression in the example, does not match the required type, typeCheck returns the Expression wrapped in for example ItemVerifier, CardinalityVerifier, or both.

typeCheck() may be called many times. typeCheck() must either raise an error if this Expression is an invalid expression. Thus, it is guaranteed that an Expression is valid after typeCheck() is called.

Parameters

context	supplies information, such as namespace bindings and available function signatures, that can be needed at compilation time. `context` is guaranteed by the caller to never null.
reqType	the static type that this Expression must match when evaluated. `reqType` is guaranteed by the caller to never null.

Returns: an Expression that can be this Expression, or another expression, which somehow is necessary for making this Expression conforming to reqType

Reimplemented from QPatternist::Expression.

Definition at line 55 of file qunresolvedvariablereference.cpp.

 {
     /* We may be called before m_replacement is called, when we're part of a
      * function body whose type checking is performed for. See
      * UserFunctionCallsite::typeCheck(). */
     if(m_replacement)
         return m_replacement->typeCheck(context, reqType);
     else
         return EmptyContainer::typeCheck(context, reqType);
 }