Base class for classes that invokes templates, such as CallTemplate and ApplyTemplate. More...

#include <qtemplateinvoker_p.h>

Inheritance diagram for QPatternist::TemplateInvoker:

Public Functions
virtual Expression::Ptr	compress (const StaticContext::Ptr &context)

virtual SequenceType::List	expectedOperandTypes () const

const WithParam::Hash &	withParams () const

Public Functions inherited from QPatternist::CallSite
virtual Expression::Ptr	body () const =0
	Returns the body of the function/template/component that is being called. More...

virtual CallTargetDescription::Ptr	callTargetDescription () const =0

virtual bool	configureRecursion (const CallTargetDescription::Ptr &sign)=0

bool	isRecursive () const

QXmlName	name () const

void	setIsRecursive (const bool value)

Public Functions inherited from QPatternist::UnlimitedContainer
virtual bool	compressOperands (const StaticContext::Ptr &)

virtual Expression::List	operands () const

virtual void	setOperands (const Expression::List &list)

	UnlimitedContainer (const Expression::List &operands=Expression::List())

Public Functions inherited from QPatternist::Expression
virtual ExpressionVisitorResult::Ptr	accept (const ExpressionVisitor::Ptr &visitor) const =0

virtual const SourceLocationReflection *	actualReflection () const
	Returns `this`. More...

virtual void	announceFocusType (const ItemType::Ptr &itemType)

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

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

virtual SequenceType::Ptr	staticType () const =0

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 ()

Public Variables
WithParam::Hash	m_withParams

Public Variables inherited from QSharedData
QAtomicInt	ref

Protected Functions
	TemplateInvoker (const WithParam::Hash &withParams, const QXmlName &name=QXmlName())

Protected Functions inherited from QPatternist::CallSite
	CallSite (const QXmlName &name=QXmlName())

Protected Functions inherited from QPatternist::UnlimitedContainer
template<CardinalityComputation suppliedCard>
SequenceType::Ptr	operandsUnionType () const

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

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

Additional Inherited Members
Public Types inherited from QPatternist::UnlimitedContainer
enum	CardinalityComputation { ProductOfCardinality, UnionOfCardinality }

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)

Protected Variables inherited from QPatternist::UnlimitedContainer
Expression::List	m_operands

Detailed Description

Base class for classes that invokes templates, such as CallTemplate and ApplyTemplate.

TemplateInvoker has the member m_withParams, which is the xsl:with-param instructions of the caller. The definite source for the expressions is m_withParams, not Expression::operands(). However, the order of operands() is defined, while m_withParams is not since it's a hash. Therefore operands() is definite on order.

TemplateInvoker is intended to be sub-classed.

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

Since: 4.5

Definition at line 79 of file qtemplateinvoker_p.h.

Constructors and Destructors

◆ TemplateInvoker()

TemplateInvoker::TemplateInvoker	(	const WithParam::Hash &	withParams,
		const QXmlName &	name = `QXmlName()`
	)

protected

withParams may be empty.

Definition at line 48 of file qtemplateinvoker.cpp.

                                                        : CallSite(name)
                                                        , m_withParams(withParams)
 {
     const WithParam::Hash::const_iterator end(m_withParams.constEnd());
 
     for(WithParam::Hash::const_iterator it(m_withParams.constBegin()); it != end; ++it)
     {
         /* In the case of for instance:
          *  <xsl:with-param name="empty_seq" as="item()"/>
          *
          * we have no default expression. */
         Q_ASSERT(it.value()->sourceExpression());
         m_operands.append(it.value()->sourceExpression());
     }
 }

Functions

◆ compress()

Expression::Ptr TemplateInvoker::compress ( const StaticContext::Ptr & context )

virtual

compress() is the last stage performs in compiling an expression, done after the initial AST build and calling typeCheck(). compress() performs crucial simplifications, either by having drastic performance implications or that some expressions depend on it for proper behavior.

The default implementation performs a sparse conditional constant propagation. In short, a recursive process is performed in the AST which examines if the Expression's operands are constant values, and if so, performs a const fold(AST rewrite) into the result of evaluating the expression in question. This default behavior can be disabled by letting properties() return DisableElimination.

This compress() stage can be relative effective due to the design of XPath, in part because intrinsic functions are heavily used. Many Expressions override compress() and do optimizations specific to what they do. Also, many Expressions performs optimizations in their typeCheck().

Parameters

context the static context. Supplies compile time information, and is the channel for communicating error messages.

See also: Wikipedia, the free encyclopedia, Sparse conditional constant propagation; Wikipedia, the free encyclopedia, Intrinsic function; Wikipedia, the free encyclopedia, Compiler optimization

Reimplemented from QPatternist::Expression.

Reimplemented in QPatternist::ApplyTemplate.

Definition at line 65 of file qtemplateinvoker.cpp.

Referenced by QPatternist::ApplyTemplate::compress().

 {
     /* CallSite::compress() may have changed our children, so update
      * our m_withParams. */
     const Expression::Ptr me(CallSite::compress(context));
     const WithParam::Hash::const_iterator end(m_withParams.constEnd());
     int exprIndex = -1;
 
     for(WithParam::Hash::const_iterator it(m_withParams.constBegin()); it != end; ++it)
     {
         if(it.value()->sourceExpression())
         {
             ++exprIndex;
             it.value()->setSourceExpression(m_operands.at(exprIndex));
         }
     }
 
     return me;
 }

◆ expectedOperandTypes()

SequenceType::List TemplateInvoker::expectedOperandTypes ( ) const

virtual

This is a bit complicated by that we have two required types, one specified by xsl:param in the template declaration, and one on xsl:with-param.

See also: UserFunctionCallsite::expectedOperandTypes(); XSL Transformations (XSLT) Version 2.0, 10.1.1 Passing Parameters to Templates

Implements QPatternist::Expression.

Definition at line 85 of file qtemplateinvoker.cpp.

 {
     SequenceType::List result;
 
     /* We don't return the type of the m_template->templateParameters(), we
      * return the type of the @c xsl:with-param first. @em After that, we
      * manually apply the parameter types in typeCheck(). */
     const WithParam::Hash::const_iterator end(m_withParams.constEnd());
 
     for(WithParam::Hash::const_iterator it(m_withParams.constBegin()); it != end; ++it)
     {
         /* We're not guaranteed to have a with-param, we may be using the
          * default value of the xsl:param. Tunnel parameters may also play
          * in. */
         result.append(it.value()->type());
     }
 
     return result;
 }

◆ withParams()

const WithParam::Hash & QPatternist::TemplateInvoker::withParams ( ) const

inline

Definition at line 108 of file qtemplateinvoker_p.h.

Referenced by QPatternist::Template::createContext().

     {
         return m_withParams;
     }

Properties

◆ m_withParams

WithParam::Hash QPatternist::TemplateInvoker::m_withParams

Definition at line 85 of file qtemplateinvoker_p.h.

Referenced by compress(), expectedOperandTypes(), TemplateInvoker(), QPatternist::CallTemplate::typeCheck(), and withParams().

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

/src/xmlpatterns/expr/qtemplateinvoker_p.h
/src/xmlpatterns/expr/qtemplateinvoker.cpp

Public Functions

Public Variables

Protected Functions

Additional Inherited Members