org.hypergraphdb.type

Interface HGTypeSchema<TypeDescriptor>

All Known Implementing Classes:

JavaTypeSchema

public interface HGTypeSchema<TypeDescriptor>

Method Summary

Methods

Modifier and Type	Method and Description
void	defineType(URI typeId, HGHandle typeHandle) Construct a new HyperGraphDB type from the specified type identifierURI.
HGHandle	findType(URI typeId) Return the HGHandle of an existing HyperGraph type that corresponds to the specified type identifier according to this schema.
HGAtomType	fromRuntimeType(HGHandle typeHandle, HGAtomType typeInstance) If a given type is wrapped under a different runtime representation by the toRuntimeType(HGHandle, HGAtomType) method, this method retrieves the underlying default representation as constructed by the type system.
String	getName() Return the name of this HGTypeSchema.
TypeDescriptor	getTypeDescriptor(URI typeId) Return the TypeDescriptor corresponding to the passed in type identifier.
void	initialize(HyperGraph graph) Initialize the schema with the HyperGraph instance to which it is bound.
void	removeType(URI typeId)
HGAtomType	toRuntimeType(HGHandle typeHandle, HGAtomType typeInstance) The type schema may wrap a given HyperGraphDB type into a different runtime instance.
URI	toTypeURI(Class<?> javaClass)
URI	toTypeURI(Object object)

Method Detail

getName

String getName()

Return the name of this HGTypeSchema. The name of a type schema uniquely identifies it.

initialize

void initialize(HyperGraph graph)

Initialize the schema with the HyperGraph instance to which it is bound. A given schema runtime instance is only bound to one database instance.

Parameters:

graph -

findType

HGHandle findType(URI typeId)

Return the HGHandle of an existing HyperGraph type that corresponds to the specified type identifier according to this schema.

Parameters:

typeId - The identifier of the type. The identifier must be valid within this schema. In particular the schema part of the URI must match this schema's name.

Returns:

The HGHandle of the HyperGraph type if it exists or null if it doesn't.

defineType

void defineType(URI typeId,
              HGHandle typeHandle)

Construct a new HyperGraphDB type from the specified type identifierURI. It is the responsibility of the schema implementation to find the correct TypeDescriptor for that identifier. The schema may return an existing HyperGraph type that corresponds to the identifier is it finds one already in the database. However, types, like other atoms, are not guaranteed to be immutable. Therefore, a schema does not "own" a HyperGraph type and the latter may be modified outside of its control.

Parameters:

typeId - The identifier of the type. The identifier must be valid within this schema. In particular the schema part of the URI must match this schema's name.

removeType

void removeType(URI typeId)

getTypeDescriptor

TypeDescriptor getTypeDescriptor(URI typeId)

Return the TypeDescriptor corresponding to the passed in type identifier.

Parameters:

typeId -

Returns:

toRuntimeType

HGAtomType toRuntimeType(HGHandle typeHandle,
                       HGAtomType typeInstance)

The type schema may wrap a given HyperGraphDB type into a different runtime instance. This is useful when atoms, and therefore in all likelihood their types as well, have different runtime representations depending on the current type schema in effect. Every time a type is loaded by the type system, the toRuntimeType of the current type schema is called to give it a change to provide a different representation.

Parameters:

typeHandle - The HGHandle of the type.

typeInstance - The type instance constructed by default from the type system.

Returns:

A (possibly) different runtime representation of the type.

fromRuntimeType

HGAtomType fromRuntimeType(HGHandle typeHandle,
                         HGAtomType typeInstance)

If a given type is wrapped under a different runtime representation by the toRuntimeType(HGHandle, HGAtomType) method, this method retrieves the underlying default representation as constructed by the type system.

Parameters:

typeHandle - The HGHandle of the type.

typeInstance - A modified runtime representation of the type.

Returns:

toTypeURI

URI toTypeURI(Object object)

toTypeURI

URI toTypeURI(Class<?> javaClass)