Nepomuk::Query::Term Class Reference

The base class for all term types. More...

#include <Nepomuk/Query/Term>

Inheritance diagram for Nepomuk::Query::Term:

List of all members.

Public Types
enum	Type {   Invalid, Literal, Resource, And,   Or, Comparison, ResourceType, Negation,   Optional }
Public Member Functions
	Term ()
	Term (const Term &other)
	~Term ()
bool	isAndTerm () const
bool	isComparisonTerm () const
bool	isLiteralTerm () const
bool	isNegationTerm () const
bool	isOptionalTerm () const
bool	isOrTerm () const
bool	isResourceTerm () const
bool	isResourceTypeTerm () const
bool	isValid () const
bool	operator!= (const Term &term) const
QDebug	operator<< (QDebug) const
Term &	operator= (const Term &other)
bool	operator== (const Term &term) const
Term	optimized () const
AndTerm	toAndTerm () const
AndTerm &	toAndTerm ()
ComparisonTerm	toComparisonTerm () const
ComparisonTerm &	toComparisonTerm ()
LiteralTerm	toLiteralTerm () const
LiteralTerm &	toLiteralTerm ()
NegationTerm	toNegationTerm () const
NegationTerm &	toNegationTerm ()
OptionalTerm	toOptionalTerm () const
OptionalTerm &	toOptionalTerm ()
OrTerm &	toOrTerm ()
OrTerm	toOrTerm () const
ResourceTerm &	toResourceTerm ()
ResourceTerm	toResourceTerm () const
ResourceTypeTerm	toResourceTypeTerm () const
ResourceTypeTerm &	toResourceTypeTerm ()
QString	toString () const
Type	type () const
Static Public Member Functions
static Term	fromString (const QString &s)
static Term	fromVariant (const Variant &variant)
Related Functions
(Note that these are not member functions.)
static Term	fromProperty (const Types::Property &property, const Variant &variant)

---

Detailed Description

The base class for all term types.

Queries are build from Term instances. A Term can have one of multiple types and subterms. See Term::Type for details on the different Term types.

Author:

Sebastian Trueg <trueg@kde.org>

Since:

4.4

Definition at line 64 of file term.h.

---

Member Enumeration Documentation

enum Nepomuk::Query::Term::Type

The type of a term identifying its meaning.

See also:

type()

Enumerator:

Invalid	An invalid term matching nothing.
Literal	A literal term is the simplest form of Term. It simply contains a literal value. See also: LiteralTerm
Resource	A resource term matches one resource by URI. See also: ResourceTerm
And	Match all resources that match all sub terms. See also: AndTerm
Or	Match all resources that match one of the sub terms. See also: OrTerm
Comparison	A comparison. The comparison operator needs to be specified in addition. A single subterm specifies the resource or value to match. See also: ComparisonTerm
ResourceType	Matches all resources of a specific type. See also: ResourceTypeTerm
Negation	A negation term inverts the meaning of its sub term. See also: NegationTerm
Optional	An optional term which marks its sub term as optional. See also: OptionalTerm Since: 4.5

Definition at line 72 of file term.h.

---

Constructor & Destructor Documentation

Nepomuk::Query::Term::Term

(

)

Constructs an invalid term.

Nepomuk::Query::Term::Term

(

const Term &

other

)

Copy constructor.

Nepomuk::Query::Term::~Term

(

)

Destructor.

---

Member Function Documentation

static Term Nepomuk::Query::Term::fromString

(

const QString &

s

)

[static]

Parse a Term that has been encoded as a string via toString().

Warning:

This method can NOT parse SPARQL syntax.

See also:

toString()

Since:

4.5

static Term Nepomuk::Query::Term::fromVariant

(

const Variant &

variant

)

[static]

Construct a Term from a Variant value.

This is a convenience method that simplifies handling Nepomuk values. However, list variants are not supported and will result in an invalid Term.

Returns:

A ResourceTerm in case variant is a resource, a LiteralTerm if variant is a supported literal value, or an invalid Term if variant is invalid or a list.

Since:

4.6

bool Nepomuk::Query::Term::isAndTerm

(

)

const

Returns:

true if this term is an AndTerm.

bool Nepomuk::Query::Term::isComparisonTerm

(

)

const

Returns:

true if this term is a ComparisonTerm.

bool Nepomuk::Query::Term::isLiteralTerm

(

)

const

Returns:

true if this term is a LiteralTerm.

bool Nepomuk::Query::Term::isNegationTerm

(

)

const

Returns:

true if this term is a NegationTerm.

bool Nepomuk::Query::Term::isOptionalTerm

(

)

const

Returns:

true if this term is a OptionalTerm.

Since:

4.5

bool Nepomuk::Query::Term::isOrTerm

(

)

const

Returns:

true if this term is an OrTerm.

bool Nepomuk::Query::Term::isResourceTerm

(

)

const

Returns:

true if this term is a ResourceTerm.

bool Nepomuk::Query::Term::isResourceTypeTerm

(

)

const

Returns:

true if this term is a ResourceTypeTerm.

bool Nepomuk::Query::Term::isValid

(

)

const

Returns:

true if the term is valid. A valid term can be used to construct a Query.

bool Nepomuk::Query::Term::operator!=

(

const Term &

term

)

const

Comparison operator.

Returns:

true if this term differs from term.

Since:

4.6

QDebug Nepomuk::Query::Term::operator<<

(

QDebug

)

const

Term& Nepomuk::Query::Term::operator=

(

const Term &

other

)

Copy operator.

bool Nepomuk::Query::Term::operator==

(

const Term &

term

)

const

Comparison operator.

Returns:

true if this term is equal to term.

Term Nepomuk::Query::Term::optimized

(

)

const

Optimizes the term without chaning its meaning.

This removes redundant terms such as NegationTerm and OptionalTerm nestings and flattens AndTerm and OrTerm hierarchies.

Returns:

An optimized version of this term.

Since:

4.6

See also:

Query::optimized()

AndTerm Nepomuk::Query::Term::toAndTerm

(

)

const

Interpret this term as a AndTerm.

Returns:

A copy of this term if its type is And, a new AndTerm otherwise.

AndTerm& Nepomuk::Query::Term::toAndTerm

(

)

Convert this term into a AndTerm.

If type is not And it will be changed and the result is a new AndTerm.

Returns:

A reference to this term as a AndTerm.

ComparisonTerm Nepomuk::Query::Term::toComparisonTerm

(

)

const

Interpret this term as a ComparisonTerm.

Returns:

A copy of this term if its type is Comparison, a new ComparisonTerm otherwise.

ComparisonTerm& Nepomuk::Query::Term::toComparisonTerm

(

)

Convert this term into a ComparisonTerm.

If type is not Comparison it will be changed and the result is a new ComparisonTerm.

Returns:

A reference to this term as a ComparisonTerm.

LiteralTerm& Nepomuk::Query::Term::toLiteralTerm

(

)

Convert this term into a LiteralTerm.

If type is not Literal it will be changed and the result is a new LiteralTerm.

Returns:

A reference to this term as a LiteralTerm.

LiteralTerm Nepomuk::Query::Term::toLiteralTerm

(

)

const

Interpret this term as a LiteralTerm.

Returns:

A copy of this term if its type is Literal, a new LiteralTerm otherwise.

NegationTerm& Nepomuk::Query::Term::toNegationTerm

(

)

Convert this term into a NegationTerm.

If type is not Negation it will be changed and the result is a new NegationTerm.

Returns:

A reference to this term as a NegationTerm.

NegationTerm Nepomuk::Query::Term::toNegationTerm

(

)

const

Interpret this term as a NegationTerm.

Returns:

A copy of this term if its type is Negation, a new NegationTerm otherwise.

OptionalTerm& Nepomuk::Query::Term::toOptionalTerm

(

)

Convert this term into a OptionalTerm.

If type is not Optional it will be changed and the result is a new OptionalTerm.

Returns:

A reference to this term as a OptionalTerm.

Since:

4.5

OptionalTerm Nepomuk::Query::Term::toOptionalTerm

(

)

const

Interpret this term as a OptionalTerm.

Returns:

A copy of this term if its type is Optional, a new OptionalTerm otherwise.

Since:

4.5

OrTerm Nepomuk::Query::Term::toOrTerm

(

)

const

Interpret this term as a OrTerm.

Returns:

A copy of this term if its type is Or, a new OrTerm otherwise.

OrTerm& Nepomuk::Query::Term::toOrTerm

(

)

Convert this term into a OrTerm.

If type is not Or it will be changed and the result is a new OrTerm.

Returns:

A reference to this term as a OrTerm.

ResourceTerm& Nepomuk::Query::Term::toResourceTerm

(

)

Convert this term into a ResourceTerm.

If type is not Resource it will be changed and the result is a new ResourceTerm.

Returns:

A reference to this term as a ResourceTerm.

ResourceTerm Nepomuk::Query::Term::toResourceTerm

(

)

const

Interpret this term as a ResourceTerm.

Returns:

A copy of this term if its type is Resource, a new ResourceTerm otherwise.

ResourceTypeTerm& Nepomuk::Query::Term::toResourceTypeTerm

(

)

Convert this term into a ResourceTypeTerm.

If type is not ClassType it will be changed and the result is a new ResourceTypeTerm.

Returns:

A reference to this term as a ResourceTypeTerm.

ResourceTypeTerm Nepomuk::Query::Term::toResourceTypeTerm

(

)

const

Interpret this term as a ResourceTypeTerm.

Returns:

A copy of this term if its type is ClassType, a new ResourceTypeTerm otherwise.

QString Nepomuk::Query::Term::toString

(

)

const

Encode the Term in a string.

Be aware that this does NOT create a SPARQL query. The returned string can be used to serialize terms that can later be read via fromString().

See also:

fromString()

Since:

4.5

Type Nepomuk::Query::Term::type

(

)

const

Returns:

the Term type.

Reimplemented in Nepomuk::Query::ResourceTypeTerm.

---

Friends And Related Function Documentation

static Term fromProperty	(	const Types::Property &	property,
		const Variant &	variant
	)		[related]

Create a term using a Types::Property and a Variant.

Sadly this cannot be modelled as an operator since it would clash with Entity::operator==().

Parameters:

property	The property to be used in the ComparisonTerm.
variant	The value to be compared to. Either ResourceTerm or LiteralTerm is used. List variants (Variant::isList()) are handled via an AndTerm meaning all values need to match.

Since:

4.6

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

• term.h