org.wikidata.wdtk.datamodel.interfaces

Interface ValueVisitor<T>

Type Parameters:

T - the return type of the visitor

All Known Implementing Classes:

DatamodelConverter

public interface ValueVisitor<T>

A visitor for the various types of values in the datamodel. This should be used to avoid any type casting or instanceof checks when processing values.

The visitor does not distinguish several types of EntityIdValue, since these are supposed to be extensible and therefore cannot be fixed in a visitor interface.

Author:

Markus Kroetzsch

Method Summary

Methods

Modifier and Type	Method and Description
T	visit(DatatypeIdValue value) Visits a DatatypeIdValue and returns a result.
T	visit(EntityIdValue value) Visits a EntityIdValue and returns a result.
T	visit(GlobeCoordinatesValue value) Visits a GlobeCoordinatesValue and returns a result.
T	visit(MonolingualTextValue value) Visits a MonolingualTextValue and returns a result.
T	visit(QuantityValue value) Visits a QuantityValue and returns a result.
T	visit(StringValue value) Visits a StringValue and returns a result.
T	visit(TimeValue value) Visits a TimeValue and returns a result.

Method Detail

visit

T visit(DatatypeIdValue value)

Visits a DatatypeIdValue and returns a result. This type of value does not occur in snaks, so some implementation will not need this method.

Parameters:

value - the value to visit

Returns:

the result for this value

visit

T visit(EntityIdValue value)

Visits a EntityIdValue and returns a result. In practice, only specific subtypes of EntityIdValue are used, such as ItemIdValue and PropertyIdValue. Since the set of possible subtypes can be extended by extensions of Wikibase, the visitor only visits the general (abstract) supertype. Implementations will have to decide if the given specific type is supported and what to do with it.

Parameters:

value - the value to visit

Returns:

the result for this value

visit

T visit(GlobeCoordinatesValue value)

Visits a GlobeCoordinatesValue and returns a result.

Parameters:

value - the value to visit

Returns:

the result for this value

visit

T visit(MonolingualTextValue value)

Visits a MonolingualTextValue and returns a result.

Parameters:

value - the value to visit

Returns:

the result for this value

visit

T visit(QuantityValue value)

Visits a QuantityValue and returns a result.

Parameters:

value - the value to visit

Returns:

the result for this value

visit

T visit(StringValue value)

Visits a StringValue and returns a result.

Parameters:

value - the value to visit

Returns:

the result for this value

visit

T visit(TimeValue value)

Visits a TimeValue and returns a result.

Parameters:

value - the value to visit

Returns:

the result for this value