Implements the function fn:avg(). More...

#include <qaggregatefns_p.h>

Inheritance diagram for QPatternist::AvgFN:

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

virtual SequenceType::Ptr	staticType () const

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

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

virtual SequenceType::List	expectedOperandTypes () const

virtual ID	id () const

virtual Expression::Properties	properties () const

virtual void	setSignature (const FunctionSignature::Ptr &sign)

virtual FunctionSignature::Ptr	signature () const

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 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 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

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
AtomicMathematician::Ptr	m_adder

AtomicMathematician::Ptr	m_divider

Additional Inherited Members
Public Types inherited from QPatternist::FunctionCall
typedef QExplicitlySharedDataPointer< FunctionCall >	Ptr

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)

Public Variables inherited from QSharedData
QAtomicInt	ref

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 ()

Protected Variables inherited from QPatternist::AddingAggregate
AtomicMathematician::Ptr	m_mather

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

Detailed Description

Implements the function fn:avg().

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

Definition at line 123 of file qaggregatefns_p.h.

Functions

◆ evaluateSingleton()

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

virtual

Reimplemented from QPatternist::Expression.

Definition at line 141 of file qaggregatefns.cpp.

 {
     const Item::Iterator::Ptr it(m_operands.first()->evaluateSequence(context));
     Item sum(it->next());
 
     xsInteger count = 0;
     while(sum)
     {
         ++count;
         const Item next(it->next());
         if(!next)
             break;
 
         sum = ArithmeticExpression::flexiblyCalculate(sum, AtomicMathematician::Add,
                                                       next, m_adder, context,
                                                       this,
                                                       ReportContext::FORG0006);
     };
 
     if(!sum)
         return Item();
 
     /* Note that we use the same m_mather which was used for adding,
      * can be worth to think about. */
     return ArithmeticExpression::flexiblyCalculate(sum, AtomicMathematician::Div,
                                                    Integer::fromValue(count),
                                                    m_divider, context,
                                                    this,
                                                    ReportContext::FORG0006);
 }

◆ staticType()

SequenceType::Ptr AvgFN::staticType ( ) const

virtual

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

Reimplemented from QPatternist::FunctionCall.

Definition at line 218 of file qaggregatefns.cpp.

 {
     const SequenceType::Ptr opt(m_operands.first()->staticType());
     ItemType::Ptr t(opt->itemType());
 
     if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t))
         t = BuiltinTypes::xsDouble; /* xsUntypedAtomics are converted to xsDouble. */
     else if(BuiltinTypes::xsInteger->xdtTypeMatches(t))
         t = BuiltinTypes::xsDecimal;
 
     /* else, it means the type is xsDayTimeDuration, xsYearMonthDuration,
      * xsDouble, xsFloat or xsAnyAtomicType, which we use as is. */
     return makeGenericSequenceType(BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(t) ? t : ItemType::Ptr(BuiltinTypes::xsAnyAtomicType),
                                    opt->cardinality().toWithoutMany());
 }

◆ typeCheck()

Expression::Ptr AvgFN::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::AddingAggregate.

Definition at line 172 of file qaggregatefns.cpp.

 {
     const Expression::Ptr me(FunctionCall::typeCheck(context, reqType));
     ItemType::Ptr t1(m_operands.first()->staticType()->itemType());
 
     if(*CommonSequenceTypes::Empty == *t1)
         return me;
     else if(*BuiltinTypes::xsAnyAtomicType == *t1 ||
             *BuiltinTypes::numeric == *t1)
         return me;
     else if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1))
     {
         m_operands.replace(0, Expression::Ptr(new UntypedAtomicConverter(m_operands.first(),
                                                                          BuiltinTypes::xsDouble)));
         t1 = m_operands.first()->staticType()->itemType();
     }
     else if(!BuiltinTypes::numeric->xdtTypeMatches(t1) &&
             !BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t1) &&
             !BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t1))
     {
         /* Translator, don't translate the type names. */
         context->error(QtXmlPatterns::tr("The first argument to %1 cannot be "
                                          "of type %2. It must be of type %3, "
                                          "%4, or %5.")
                           .arg(signature())
                           .arg(formatType(context->namePool(), m_operands.first()->staticType()))
                           .arg(formatType(context->namePool(), BuiltinTypes::numeric))
                           .arg(formatType(context->namePool(), BuiltinTypes::xsYearMonthDuration))
                           .arg(formatType(context->namePool(), BuiltinTypes::xsDayTimeDuration)),
                        ReportContext::FORG0006, this);
     }
 
     if(!m_operands.first()->staticType()->cardinality().allowsMany())
         return m_operands.first();
 
     /* We use CommonValues::IntegerOne here because it is an arbitrary Expression
      * of type xs:integer */
     Expression::Ptr op2(wrapLiteral(CommonValues::IntegerOne, context, this));
     m_adder = ArithmeticExpression::fetchMathematician(m_operands.first(), m_operands.first(),
                                                        AtomicMathematician::Add, true, context, this);
     m_divider = ArithmeticExpression::fetchMathematician(m_operands.first(), op2,
                                                          AtomicMathematician::Div, true, context, this);
     return me;
 }

Properties

◆ m_adder

AtomicMathematician::Ptr QPatternist::AvgFN::m_adder

private

Definition at line 132 of file qaggregatefns_p.h.

◆ m_divider

AtomicMathematician::Ptr QPatternist::AvgFN::m_divider

private

Definition at line 133 of file qaggregatefns_p.h.

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

/src/xmlpatterns/functions/qaggregatefns_p.h
/src/xmlpatterns/functions/qaggregatefns.cpp

Public Functions

Properties

Additional Inherited Members

Detailed Description

Functions

◆ evaluateSingleton()

◆ staticType()

◆ typeCheck()

Properties

◆ m_adder

◆ m_divider