Trait ObjectIdMapping 

pub trait ObjectIdMapping:
    Debug
    + Send
    + Sync {
    // Required methods
    fn encoding(&self) -> ObjectIdEncoding;
    fn try_get_object_id(
        &self,
        scalar: &PlainTermScalar,
    ) -> Result<Option<ObjectIdScalar>, ObjectIdMappingError>;
    fn encode_array(
        &self,
        array: &PlainTermArray,
    ) -> Result<ObjectIdArray, ObjectIdMappingError>;
    fn decode_array(
        &self,
        array: &ObjectIdArray,
    ) -> Result<PlainTermArray, ObjectIdMappingError>;
    fn decode_array_to_typed_value(
        &self,
        array: &ObjectIdArray,
    ) -> Result<TypedValueArray, ObjectIdMappingError>;

    // Provided methods
    fn encode_scalar(
        &self,
        scalar: &PlainTermScalar,
    ) -> Result<ObjectIdScalar, ObjectIdMappingError> { ... }
    fn decode_scalar(
        &self,
        scalar: &ObjectIdScalar,
    ) -> Result<PlainTermScalar, ObjectIdMappingError> { ... }
    fn decode_scalar_to_typed_value(
        &self,
        scalar: &ObjectIdScalar,
    ) -> Result<TypedValueScalar, ObjectIdMappingError> { ... }
}

The object id mapping is responsible for mapping between object ids and RDF terms in the ObjectIdEncoding.

The mapping between the object id and the RDF term is bijective. In other words, each distinct RDF term maps to exactly one object id, while each object id maps to exactly one RDF term. As a result, operations that rely on the equality of RDF terms (SAME_TERM) can directly work with the object ids. Joining solution sets is the most important example.

Typed Values

To speed up decoding object ids directly into the TypedValueEncoding, the trait also contains methods for directly mapping object ids to their typed values. This can be implemented in two ways:

1. Decode the object id to a plain term and then translate the term to a typed value
2. Maintain a second mapping from the object ids to the typed value of their associated RDF term

Contrary to the mapping between RDF terms and object ids, the mapping between typed values and object ids is not bijective. A single typed value can map to multiple object ids. For example, this is the case for the two RDF terms "01"^^xsd:integer and "1"^^xsd:integer.

Required Methods

fn encoding(&self) -> ObjectIdEncoding

Returns the encoding.

fn try_get_object_id( &self, scalar: &PlainTermScalar, ) -> Result<Option<ObjectIdScalar>, ObjectIdMappingError>

Try to retrieve the object id of the given scalar.

This method does not automatically create a mapping. See Self::encode_scalar for this functionality.

fn encode_array( &self, array: &PlainTermArray, ) -> Result<ObjectIdArray, ObjectIdMappingError>

Encodings the entire array as an ObjectIdArray. Automatically creates a mapping for a fresh object id if a term is not yet mapped.

fn decode_array( &self, array: &ObjectIdArray, ) -> Result<PlainTermArray, ObjectIdMappingError>

Decodes the entire array as a PlainTermArray.

fn decode_array_to_typed_value( &self, array: &ObjectIdArray, ) -> Result<TypedValueArray, ObjectIdMappingError>

Decodes the entire array as a TypedValueArray.

Provided Methods

fn encode_scalar( &self, scalar: &PlainTermScalar, ) -> Result<ObjectIdScalar, ObjectIdMappingError>

Encodes a single scalar as an ObjectIdScalar. Automatically creates a mapping for a fresh object id if the term is not yet mapped.

fn decode_scalar( &self, scalar: &ObjectIdScalar, ) -> Result<PlainTermScalar, ObjectIdMappingError>

Decodes a single scalar as a PlainTermScalar.

fn decode_scalar_to_typed_value( &self, scalar: &ObjectIdScalar, ) -> Result<TypedValueScalar, ObjectIdMappingError>

Decodes a single scalar as a TypedValueScalar.

Implementors

impl ObjectIdMapping for MemObjectIdMapping