Implements arithmetics, such as multiplication and subtraction. More...

#include <qarithmeticexpression_p.h>

Inheritance diagram for QPatternist::ArithmeticExpression:

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

	ArithmeticExpression (const Expression::Ptr &operand1, const AtomicMathematician::Operator op, const Expression::Ptr &operand2)

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

virtual SequenceType::List	expectedOperandTypes () const

AtomicMathematician::Operator	operatorID () const

virtual SequenceType::Ptr	staticType () const

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

Public Functions inherited from QPatternist::PairContainer
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 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

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	~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 ()

Static Public Functions
static AtomicMathematician::Ptr	fetchMathematician (Expression::Ptr &t1, Expression::Ptr &t2, const AtomicMathematician::Operator op, const bool issueError, const ReportContext::Ptr &context, const SourceLocationReflection *const reflection, const ReportContext::ErrorCode code=ReportContext::XPTY0004, const bool isCompat=false)

static Item	flexiblyCalculate (const Item &op1, const AtomicMathematician::Operator op, const Item &op2, const AtomicMathematician::Ptr &mather, const DynamicContext::Ptr &context, const SourceLocationReflection *const reflection, const ReportContext::ErrorCode code=ReportContext::XPTY0004, const bool isCompat=false)

Static Public Functions inherited from QPatternist::Expression
static void	rewrite (Expression::Ptr &old, const Expression::Ptr &New, const StaticContext::Ptr &context)

Properties
bool	m_isCompat

AtomicMathematician::Ptr	m_mather

const AtomicMathematician::Operator	m_op

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

Public Variables inherited from QSharedData
QAtomicInt	ref

Protected Functions inherited from QPatternist::PairContainer
	PairContainer (const Expression::Ptr &operand1, const Expression::Ptr &operand2)

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::PairContainer
Expression::Ptr	m_operand1

Expression::Ptr	m_operand2

Detailed Description

Implements arithmetics, such as multiplication and subtraction.

Optimizations: there's some operator/value combos that are no ops. For instance, 0 +

, which is the case of unary plus. We can't compile those away early due to that type checks needs to be done but one can check for them in compress().

See also: XML Path Language (XPath) 2.0, 3.4 Arithmetic Expressions

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

Definition at line 78 of file qarithmeticexpression_p.h.

Constructors and Destructors

◆ ArithmeticExpression()

ArithmeticExpression::ArithmeticExpression	(	const Expression::Ptr &	operand1,
		const AtomicMathematician::Operator	op,
		const Expression::Ptr &	operand2
	)

Definition at line 58 of file qarithmeticexpression.cpp.

                                                                      : PairContainer(op1, op2)
                                                                        , m_op(op)
                                                                        , m_isCompat(false)
 {
 }

Functions

◆ accept()

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

virtual

Implements QPatternist::Expression.

Definition at line 358 of file qarithmeticexpression.cpp.

Referenced by fetchMathematician().

 {
     return visitor->visit(this);
 }

◆ evaluateSingleton()

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

virtual

Reimplemented from QPatternist::Expression.

Reimplemented in QPatternist::UnaryExpression.

Definition at line 66 of file qarithmeticexpression.cpp.

 {
     const Item op1(m_operand1->evaluateSingleton(context));
     if(!op1)
         return Item();
 
     const Item op2(m_operand2->evaluateSingleton(context));
     if(!op2)
         return Item();
 
     return flexiblyCalculate(op1, m_op, op2, m_mather, context, this,
                              ReportContext::XPTY0004, m_isCompat);
 }

◆ expectedOperandTypes()

SequenceType::List ArithmeticExpression::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.

Definition at line 350 of file qarithmeticexpression.cpp.

 {
     SequenceType::List result;
     result.append(CommonSequenceTypes::ZeroOrOneAtomicType);
     result.append(CommonSequenceTypes::ZeroOrOneAtomicType);
     return result;
 }

◆ fetchMathematician()

AtomicMathematician::Ptr ArithmeticExpression::fetchMathematician	(	Expression::Ptr &	t1,
		Expression::Ptr &	t2,
		const AtomicMathematician::Operator	op,
		const bool	issueError,
		const ReportContext::Ptr &	context,
		const SourceLocationReflection *const	reflection,
		const ReportContext::ErrorCode	code = `ReportContext::XPTY0004`,
		const bool	isCompat = `false`
	)

static

Definition at line 169 of file qarithmeticexpression.cpp.

Referenced by flexiblyCalculate(), typeCheck(), QPatternist::AddingAggregate::typeCheck(), and QPatternist::AvgFN::typeCheck().

 {
     ItemType::Ptr t1(op1->staticType()->itemType());
     ItemType::Ptr t2(op2->staticType()->itemType());
 
     if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t1)
        || (isCompat && (BuiltinTypes::xsString->xdtTypeMatches(t1)
                         || BuiltinTypes::xsDecimal->xdtTypeMatches(t1))))
     {
         op1 = Expression::Ptr(new UntypedAtomicConverter(op1, BuiltinTypes::xsDouble));
         /* The types might have changed, reload. */
         t1 = op1->staticType()->itemType();
     }
 
     if(BuiltinTypes::xsUntypedAtomic->xdtTypeMatches(t2)
        || (isCompat && (BuiltinTypes::xsString->xdtTypeMatches(t1)
                         || BuiltinTypes::xsDecimal->xdtTypeMatches(t1))))
     {
         op2 = Expression::Ptr(new UntypedAtomicConverter(op2, BuiltinTypes::xsDouble));
         /* The types might have changed, reload. */
         t2 = op2->staticType()->itemType();
     }
 
     const AtomicMathematicianLocator::Ptr locator
         (static_cast<const AtomicType *>(t1.data())->mathematicianLocator());
 
     if(!locator)
     {
         if(!issueError)
             return AtomicMathematician::Ptr();
 
         context->error(QtXmlPatterns::tr(
                        "Operator %1 cannot be used on type %2.")
                        .arg(formatKeyword(AtomicMathematician::displayName(op)))
                        .arg(formatType(context->namePool(), t1)),
                        code, reflection);
         return AtomicMathematician::Ptr();
     }
 
     const AtomicMathematician::Ptr comp
         (static_cast<const AtomicType *>(t2.data())->accept(locator, op, reflection));
 
     if(comp)
         return comp;
 
     if(!issueError)
         return AtomicMathematician::Ptr();
 
     context->error(QtXmlPatterns::tr("Operator %1 cannot be used on "
                                      "atomic values of type %2 and %3.")
                    .arg(formatKeyword(AtomicMathematician::displayName(op)))
                    .arg(formatType(context->namePool(), t1))
                    .arg(formatType(context->namePool(), t2)),
                    code, reflection);
     return AtomicMathematician::Ptr();
 }

◆ flexiblyCalculate()

Item ArithmeticExpression::flexiblyCalculate	(	const Item &	op1,
		const AtomicMathematician::Operator	op,
		const Item &	op2,
		const AtomicMathematician::Ptr &	mather,
		const DynamicContext::Ptr &	context,
		const SourceLocationReflection *const	reflection,
		const ReportContext::ErrorCode	code = `ReportContext::XPTY0004`,
		const bool	isCompat = `false`
	)

static

Definition at line 112 of file qarithmeticexpression.cpp.

Referenced by evaluateSingleton(), QPatternist::AvgFN::evaluateSingleton(), and QPatternist::SumFN::evaluateSingleton().

 {
     if(mather)
         return mather->calculate(op1, op, op2, context);
 
     /* This is a very heavy code path. */
     Expression::Ptr a1(new DelegatingReflectionExpression(op1, reflection));
     Expression::Ptr a2(new DelegatingReflectionExpression(op2, reflection));
 
     const AtomicMathematician::Ptr ingela(fetchMathematician(a1, a2, op, true, context, reflection, code, isCompat));
 
     return ingela->calculate(a1->evaluateSingleton(context),
                              op,
                              a2->evaluateSingleton(context),
                              context);
 }

◆ operatorID()

AtomicMathematician::Operator QPatternist::ArithmeticExpression::operatorID ( ) const

inline

Definition at line 122 of file qarithmeticexpression_p.h.

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

     {
         return m_op;
     }

◆ staticType()

SequenceType::Ptr ArithmeticExpression::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 233 of file qarithmeticexpression.cpp.

 {
     Cardinality card;
 
     /* These variables are important because they ensure staticType() only
      * gets called once from this function. Before, this lead to strange
      * semi-infinite recursion involving many arithmetic expressions. */
     const SequenceType::Ptr st1(m_operand1->staticType());
     const SequenceType::Ptr st2(m_operand2->staticType());
 
     if(st1->cardinality().allowsEmpty() ||
        st2->cardinality().allowsEmpty())
     {
         card = Cardinality::zeroOrOne();
     }
     else
         card = Cardinality::exactlyOne();
 
     if(m_op == AtomicMathematician::IDiv)
         return makeGenericSequenceType(BuiltinTypes::xsInteger, card);
 
     const ItemType::Ptr t1(st1->itemType());
     const ItemType::Ptr t2(st2->itemType());
     ItemType::Ptr returnType;
 
     /* Please, make this beautiful? */
     if(BuiltinTypes::xsTime->xdtTypeMatches(t1) ||
        BuiltinTypes::xsDate->xdtTypeMatches(t1) ||
        BuiltinTypes::xsDateTime->xdtTypeMatches(t1))
     {
         if(BuiltinTypes::xsDuration->xdtTypeMatches(t2))
             returnType = t1;
         else
             returnType = BuiltinTypes::xsDayTimeDuration;
     }
     else if(BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t1))
     {
         if(m_op == AtomicMathematician::Div &&
            BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t2))
         {
             returnType = BuiltinTypes::xsDecimal;
         }
         else if(BuiltinTypes::numeric->xdtTypeMatches(t2))
             returnType = BuiltinTypes::xsYearMonthDuration;
         else
             returnType = t2;
     }
     else if(BuiltinTypes::xsYearMonthDuration->xdtTypeMatches(t2))
     {
         returnType = BuiltinTypes::xsYearMonthDuration;
     }
     else if(BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t1))
     {
         if(m_op == AtomicMathematician::Div &&
            BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t2))
         {
             returnType = BuiltinTypes::xsDecimal;
         }
         else if(BuiltinTypes::numeric->xdtTypeMatches(t2))
             returnType = BuiltinTypes::xsDayTimeDuration;
         else
             returnType = t2;
     }
     else if(BuiltinTypes::xsDayTimeDuration->xdtTypeMatches(t2))
     {
         returnType = BuiltinTypes::xsDayTimeDuration;
     }
     else if(BuiltinTypes::xsDouble->xdtTypeMatches(t1) ||
             BuiltinTypes::xsDouble->xdtTypeMatches(t2))
     {
         returnType = BuiltinTypes::xsDouble;
     }
     else if(BuiltinTypes::xsFloat->xdtTypeMatches(t1) ||
             BuiltinTypes::xsFloat->xdtTypeMatches(t2))
     {
         if(m_isCompat)
             returnType = BuiltinTypes::xsFloat;
         else
             returnType = BuiltinTypes::xsDouble;
     }
     else if(BuiltinTypes::xsInteger->xdtTypeMatches(t1) &&
             BuiltinTypes::xsInteger->xdtTypeMatches(t2))
     {
         if(m_isCompat)
             returnType = BuiltinTypes::xsDouble;
         else
         {
             /* "A div B  numeric  numeric  op:numeric-divide(A, B)
              * numeric; but xs:decimal if both operands are xs:integer" */
             if(m_op == AtomicMathematician::Div)
                 returnType = BuiltinTypes::xsDecimal;
             else
                 returnType = BuiltinTypes::xsInteger;
         }
     }
     else if(m_isCompat && (BuiltinTypes::xsInteger->xdtTypeMatches(t1) &&
                            BuiltinTypes::xsInteger->xdtTypeMatches(t2)))
     {
         returnType = BuiltinTypes::xsDouble;
     }
     else
     {
         /* If typeCheck() has been called, our operands conform to expectedOperandTypes(), and
          * the types are hence either xs:decimals, or xs:anyAtomicType(meaning the static type could
          * not be inferred), or empty-sequence(). So we use the union of the two types. The combinations
          * could also be wrong.*/
         returnType = t1 | t2;
 
         /* However, if we're called before typeCheck(), we could potentially have nodes, so we need to make
          * sure that the type is at least atomic. */
         if(!BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(returnType))
             returnType = BuiltinTypes::xsAnyAtomicType;
     }
 
     return makeGenericSequenceType(returnType, card);
 }

◆ typeCheck()

Expression::Ptr ArithmeticExpression::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 136 of file qarithmeticexpression.cpp.

 {
     m_isCompat = context->compatModeEnabled();
 
     const Expression::Ptr me(PairContainer::typeCheck(context, reqType));
     const ItemType::Ptr t1(m_operand1->staticType()->itemType());
     const ItemType::Ptr t2(m_operand2->staticType()->itemType());
 
     if(*CommonSequenceTypes::Empty == *t1 ||
        *CommonSequenceTypes::Empty == *t2)
     {
         return EmptySequence::create(this, context);
     }
 
     if(*BuiltinTypes::xsAnyAtomicType == *t1    ||
        *BuiltinTypes::xsAnyAtomicType == *t2    ||
        *BuiltinTypes::numeric == *t1            ||
        *BuiltinTypes::numeric == *t2)
     {
         /* The static type of (at least) one of the operands could not
          * be narrowed further than xs:anyAtomicType, so we do the operator
          * lookup at runtime. */
         return me;
     }
 
     m_mather = fetchMathematician(m_operand1, m_operand2, m_op, true, context, this,
                                   ReportContext::XPTY0004, m_isCompat);
 
     return me;
 }

Properties

◆ m_isCompat

bool QPatternist::ArithmeticExpression::m_isCompat

private

Definition at line 119 of file qarithmeticexpression_p.h.

Referenced by evaluateSingleton(), staticType(), and typeCheck().

◆ m_mather

AtomicMathematician::Ptr QPatternist::ArithmeticExpression::m_mather

private

Definition at line 118 of file qarithmeticexpression_p.h.

Referenced by evaluateSingleton(), and typeCheck().

◆ m_op

const AtomicMathematician::Operator QPatternist::ArithmeticExpression::m_op

private

Definition at line 117 of file qarithmeticexpression_p.h.

Referenced by evaluateSingleton(), staticType(), and typeCheck().

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

/src/xmlpatterns/expr/qarithmeticexpression_p.h
/src/xmlpatterns/expr/qarithmeticexpression.cpp

Public Functions

Static Public Functions

Properties

Additional Inherited Members

Detailed Description

Constructors and Destructors

◆ ArithmeticExpression()

Functions

◆ accept()

◆ evaluateSingleton()

◆ expectedOperandTypes()

◆ fetchMathematician()

◆ flexiblyCalculate()

◆ operatorID()

◆ staticType()

◆ typeCheck()

Properties

◆ m_isCompat

◆ m_mather

◆ m_op