QPatternist::ItemType Class Reference

Base class for the XPath Data Model's type hierarchy. More...

#include <qitemtype_p.h>

Inheritance diagram for QPatternist::ItemType:

Public Types
enum	Category { NodeNameTest = 1, Other = 2 }
enum	InstanceOf { ClassLocalNameTest, ClassNamespaceNameTest, ClassQNameTest, ClassOther }
typedef QList< ItemType::Ptr >	List
typedef QExplicitlySharedDataPointer< ItemType >	Ptr

Public Functions
virtual ItemType::Ptr	atomizedType () const =0
virtual QString	displayName (const NamePool::Ptr &np) const =0
virtual InstanceOf	instanceOf () const
virtual bool	isAtomicType () const =0
virtual bool	isNodeType () const =0
virtual bool	itemMatches (const Item &item) const =0
	ItemType ()
virtual Category	itemTypeCategory () const
bool	operator!= (const ItemType &other) const
virtual bool	operator== (const ItemType &other) const
virtual const ItemType &	operator| (const ItemType &other) const
virtual ItemType::Ptr	xdtSuperType () const =0
virtual bool	xdtTypeMatches (const ItemType::Ptr &other) const =0
	Returns true if other matches this type. That is, if other is equal to this type or a subtype of this type. More...
virtual	~ItemType ()
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...

Related Functions
(Note that these are not member functions.)
ItemType::Ptr	operator| (const ItemType::Ptr &op1, const ItemType::Ptr &op2)
void	operator|= (ItemType::Ptr &op1, const ItemType::Ptr &op2)
	Computes the union type of op1 and op2, and assigns it to op1. More...

Additional Inherited Members
Public Variables inherited from QSharedData
QAtomicInt	ref

Detailed Description

Base class for the XPath Data Model's type hierarchy.

It can not be instantiated, but it's possible via ItemType's two subtypes: Nodes, represented by QXmlNodeModelIndex, and atom types, represented by AtomicType.

ItemType tries to by its design stay close to the notation used in Formal Semantics. The operator|() is a good example, it allow typing code to be written similar to how inference rules in the specification are written.

Author

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

Definition at line 82 of file qitemtype_p.h.

Typedefs

List

typedef QList<ItemType::Ptr> QPatternist::ItemType::List

A list of ItemType instances, each wrapped in a smart pointer.

Definition at line 92 of file qitemtype_p.h.

Ptr

typedef QExplicitlySharedDataPointer<ItemType> QPatternist::ItemType::Ptr

A smart pointer wrapping ItemType instances.

Definition at line 88 of file qitemtype_p.h.

Enumerations

Category

enum QPatternist::ItemType::Category

Enumerator
NodeNameTest
Other

Definition at line 96 of file qitemtype_p.h.

        {
            NodeNameTest = 1,
            Other        = 2
        };

InstanceOf

enum QPatternist::ItemType::InstanceOf

Enumerator
ClassLocalNameTest
ClassNamespaceNameTest
ClassQNameTest
ClassOther

Definition at line 217 of file qitemtype_p.h.

        {
            ClassLocalNameTest,
            ClassNamespaceNameTest,
            ClassQNameTest,
            ClassOther
        };

Constructors and Destructors

~ItemType()

ItemType::~ItemType ( )

virtual

Definition at line 52 of file qitemtype.cpp.

{
}

ItemType()

QPatternist::ItemType::ItemType ( )

inline

Definition at line 232 of file qitemtype_p.h.

        {
        }

Functions

atomizedType()

virtual ItemType::Ptr QPatternist::ItemType::atomizedType ( ) const

pure virtual

Determines the atomic type that the resulting sequence after atomization of this node would be an instance of. For example, for document node, xs:untypedAtomic is returned. Phrased differently, the returned type is the type of the result of the typed-value accessor.

If the type cannot be atomized, it returns null.

This function is also defined on SchemaType, because some schema types can also be atomized.

See also

SchemaType::atomizedType()

XQuery 1.0 and XPath 2.0 Data Model, 5.15 typed-value Accessor

XQuery 1.0 and XPath 2.0 Formal Semantics, data on auxiliary judgment

Returns

the atomic type that the resulting sequence when performing atomization is an instance of.

Implemented in QPatternist::MultiItemType, QPatternist::AtomicType, QPatternist::NoneType, QPatternist::EBVType, QPatternist::EmptySequenceType, QPatternist::NumericType, QPatternist::AnyItemType, QPatternist::AnyNodeType, QPatternist::BuiltinNodeType< kind >, and QPatternist::AbstractNodeTest.

Referenced by QPatternist::AbstractNodeTest::atomizedType().

displayName()

virtual QString QPatternist::ItemType::displayName ( const NamePool::Ptr &  np ) const

pure virtual

Returns

a string representing the type. Used for diagnostic purposes. For a type whose name is a QName, a lexical representation should be returned with the prefix being a conventional one. Examples of a display names are "item()" and "xs:nonPositiveInteger".

Implemented in QPatternist::NOTATIONType, QPatternist::DerivedStringType< derivedType >, QPatternist::StringType, QPatternist::QNameType, QPatternist::AnyURIType, QPatternist::HexBinaryType, QPatternist::Base64BinaryType, QPatternist::BooleanType, QPatternist::GMonthType, QPatternist::GDayType, QPatternist::GMonthDayType, QPatternist::GYearType, QPatternist::GYearMonthType, QPatternist::DerivedIntegerType< derivedType >, QPatternist::IntegerType, QPatternist::DecimalType, QPatternist::FloatType, QPatternist::DoubleType, QPatternist::DayTimeDurationType, QPatternist::YearMonthDurationType, QPatternist::DurationType, QPatternist::SchemaTimeType, QPatternist::DateType, QPatternist::DateTimeType, QPatternist::UntypedAtomicType, QPatternist::AtomicType, QPatternist::MultiItemType, QPatternist::EmptySequenceType, QPatternist::EBVType, QPatternist::NoneType, QPatternist::AnyAtomicType, QPatternist::BuiltinNodeType< kind >, QPatternist::LocalNameTest, QPatternist::NamespaceNameTest, QPatternist::QNameTest, QPatternist::NumericType, QPatternist::AnyNodeType, and QPatternist::AnyItemType.

Referenced by QPatternist::GenericSequenceType::displayName(), QPatternist::QNameTest::displayName(), and QPatternist::LocalNameTest::displayName().

instanceOf()

ItemType::InstanceOf ItemType::instanceOf ( ) const

virtual

Determines what class this ItemType is an instance of. This is in needed in some implementations of operator operator==(). By default, Other is returned.

Reimplemented in QPatternist::QNameTest, QPatternist::LocalNameTest, and QPatternist::NamespaceNameTest.

Definition at line 98 of file qitemtype.cpp.

Referenced by QPatternist::LocalNameTest::operator==(), QPatternist::QNameTest::operator==(), and QPatternist::NamespaceNameTest::operator==().

{
    return ClassOther;
}

isAtomicType()

virtual bool QPatternist::ItemType::isAtomicType ( ) const

pure virtual

Implemented in QPatternist::MultiItemType, QPatternist::AtomicType, QPatternist::NoneType, QPatternist::EBVType, QPatternist::AnyItemType, QPatternist::EmptySequenceType, QPatternist::NumericType, and QPatternist::AnyNodeType.

Referenced by QPatternist::CastableAs::CastableAs(), QPatternist::CastAs::CastAs(), and QPatternist::AtomicType::xdtTypeMatches().

isNodeType()

virtual bool QPatternist::ItemType::isNodeType ( ) const

pure virtual

Implemented in QPatternist::NoneType, QPatternist::EBVType, QPatternist::MultiItemType, QPatternist::AtomicType, QPatternist::EmptySequenceType, QPatternist::AnyItemType, QPatternist::NumericType, and QPatternist::AnyNodeType.

Referenced by QPatternist::AbstractNodeTest::xdtTypeMatches(), QPatternist::AnyNodeType::xdtTypeMatches(), and QPatternist::XSLTNodeTest::xdtTypeMatches().

itemMatches()

virtual bool QPatternist::ItemType::itemMatches ( const Item &  item ) const

pure virtual

Parameters

item	the item that is to be matched. This is guaranteed by the caller to never be null.

Implemented in QPatternist::MultiItemType, QPatternist::AtomicType, QPatternist::EmptySequenceType, QPatternist::EBVType, QPatternist::AnyItemType, QPatternist::LocalNameTest, QPatternist::NamespaceNameTest, QPatternist::NoneType, QPatternist::QNameTest, QPatternist::XSLTNodeTest, QPatternist::AnyNodeType, QPatternist::BuiltinNodeType< kind >, and QPatternist::NumericType.

Referenced by QPatternist::InstanceOf::evaluateEBV(), QPatternist::LocalNameTest::itemMatches(), QPatternist::NamespaceNameTest::itemMatches(), QPatternist::QNameTest::itemMatches(), QPatternist::AxisStep::mapToItem(), and QPatternist::ItemVerifier::verifyItem().

itemTypeCategory()

ItemType::Category ItemType::itemTypeCategory ( ) const

virtual

Returns

always Other

Definition at line 88 of file qitemtype.cpp.

{
    return Other;
}

operator!=()

bool QPatternist::ItemType::operator!= ( const ItemType &  other ) const

inline

Returns

the result of operator==() negated.

Definition at line 256 of file qitemtype_p.h.

    {
        return this != &other;
    }

operator==()

bool ItemType::operator== ( const ItemType &  other ) const

virtual

Determines whether this ItemType is equal to other.

Many types are represented by singleton instances. For example, there exists only one instance of IntegerType. This operator==() takes advantage of that and uses equalness of object addresses for determining semantic equalness. This function is as a result fast.

However, it's overridden in some cases, such as for name tests, where it's not guaranteed that there exists two types.

Returns

true if this ItemType is equal to other, otherwise false.

Reimplemented in QPatternist::LocalNameTest, QPatternist::NamespaceNameTest, and QPatternist::QNameTest.

Definition at line 93 of file qitemtype.cpp.

{
    return this == &other;
}

operator|()

const ItemType & ItemType::operator| ( const ItemType &  other ) const

virtual

Determines the super type that is closest to this ItemType and other. That is, the parent type of them both. For example, for the type xs:integer and xs:string the parent type is xs:anyAtomicType. For xs:NOTATION and processing-instruction(), it is item(), to name another example.

This function can be seen as the type function prime(Type), defined in Formal Semantics.

This walks the XPath Data Model type hierarchy, not the W3C XML Schema hierarchy.

Parameters

other

the item type 'this' object, should be compared with. Invoking xdtSuperType on 'this' object with other as argument yields the same result as invoking the function on other with 'this' as argument.

Returns

the parent type of 'this' and other

See also

XQuery 1.0 and XPath 2.0 Formal Semantics, Prime Types, type function prime(Type)

Reimplemented in QPatternist::NoneType.

Definition at line 56 of file qitemtype.cpp.

{
    const ItemType *ca = this;

    if(other == *CommonSequenceTypes::None)
        return *ca;

    if(*ca == *CommonSequenceTypes::Empty)
        return other;
    else if(other == *CommonSequenceTypes::Empty)
        return *ca;

    do
    {
        const ItemType *cb = &other;
        do
        {
            if(*ca == *cb)
                return *ca;

            cb = cb->xdtSuperType().data();
        }
        while(cb);

        ca = ca->xdtSuperType().data();
    }
    while(ca);

    Q_ASSERT_X(false, Q_FUNC_INFO, "We should never reach this line.");
    return *this;
}

xdtSuperType()

virtual ItemType::Ptr QPatternist::ItemType::xdtSuperType ( ) const

pure virtual

Determines the type's parent type in the XPath Data Model hierarchy. For example, for the type xs:anyAtomicType, the super type in the XPath Data Model is item(), not xs:anySimpleType. SchemaType::xdtSuperType navigates the schema hierarchy.

See also

SchemaType::wxsSuperType()

Returns

the type's super type.

Implemented in QPatternist::NoneType, QPatternist::MultiItemType, QPatternist::EBVType, QPatternist::NumericType, QPatternist::BuiltinAtomicType, QPatternist::EmptySequenceType, QPatternist::AnyAtomicType, QPatternist::AnyItemType, QPatternist::BuiltinNodeType< kind >, QPatternist::AnyNodeType, QPatternist::XSLTNodeTest, and QPatternist::AbstractNodeTest.

Referenced by operator|(), QPatternist::AbstractNodeTest::xdtTypeMatches(), QPatternist::XSLTNodeTest::xdtTypeMatches(), and QPatternist::AtomicType::xdtTypeMatches().

xdtTypeMatches()

virtual bool QPatternist::ItemType::xdtTypeMatches ( const ItemType::Ptr &  other ) const

pure virtual

Returns true if other matches this type. That is, if other is equal to this type or a subtype of this type.

For instance this statements evaluates to true:

BuiltinTypes::xsAnyAtomicType->xdtTypeMatches(BuiltinTypes::xsString);

but this evaluates to false:

BuiltinTypes::attribute->xdtTypeMatches(BuiltinTypes::node);

Parameters

other

the other ItemType that is to be matched. This is guaranteed by the caller to never be null.

Implemented in QPatternist::AtomicType, QPatternist::MultiItemType, QPatternist::AnyItemType, QPatternist::EBVType, QPatternist::EmptySequenceType, QPatternist::NoneType, QPatternist::XSLTNodeTest, QPatternist::AnyNodeType, QPatternist::BuiltinNodeType< kind >, QPatternist::NumericType, and QPatternist::AbstractNodeTest.

Referenced by QPatternist::BySequenceTypeIdentifier::matches(), QPatternist::SequenceType::matches(), and QPatternist::CastAs::typeCheck().

Friends and Related Functions

operator|()

ItemType::Ptr operator| ( const ItemType::Ptr &  op1, const ItemType::Ptr &  op2  )

related

This operator exists for making it easier to use the ItemType class, which always are wrapped in ItemType::Ptr, by taking care of the dereferencing of ItemType::Ptr instances. Semantically, it performs the same as ItemType's operator of the same name.

See also

ItemType::operator|()

operator|=(ItemType::Ptr &, const ItemType::Ptr &)

Definition at line 250 of file qitemtype_p.h.

    {
        return ItemType::Ptr(const_cast<ItemType *>(&(*op1 | *op2)));
    }

operator|=()

void operator|= ( ItemType::Ptr &  op1, const ItemType::Ptr &  op2  )

related

Computes the union type of op1 and op2, and assigns it to op1.

This operator exists for making it easier to use the ItemType class, which always are wrapped in ItemType::Ptr, by taking care of the dereferencing of the ItemType::Ptr instances.

See also

operator|(const ItemType::Ptr &, const ItemType::Ptr &)

Parameters

op1	if null, op2 is returned unchanged
op2	the other operand

Definition at line 273 of file qitemtype_p.h.

Referenced by QRect::QRect().

    {
        op1 = op1 | op2;
    }

---

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

• /src/xmlpatterns/type/qitemtype_p.h
• /src/xmlpatterns/type/qitemtype.cpp