Struct QueryGraph 

pub struct QueryGraph<'a, G: GraphRead + ?Sized> { /* private fields */ }

Evaluate SPARQL over the exact graph contexts exposed by a borrowed source. Compose union/overlay views explicitly before constructing this adapter. The adapter adds no default union, snapshots, or graph-name collections. See the crate architecture and runnable example.

Implementations

impl<'a, G: GraphRead + ?Sized> QueryGraph<'a, G>

pub fn new(source: &'a G) -> Self

Borrow a consistent graph source for the lifetime of query evaluation.

Trait Implementations

impl<'a, G: GraphRead + ?Sized + 'a> QueryableDataset<'a> for QueryGraph<'a, G>

type InternalTerm = Term

Internal representation of an RDF term

type Error = Error

Error returned by the dataset.

fn internal_quads_for_pattern( &self, subject: Option<&Term>, predicate: Option<&Term>, object: Option<&Term>, graph_name: Option<Option<&Term>>, ) -> impl Iterator<Item = Result<InternalQuad<Term>>> + use<'a, G>

Fetches quads according to a pattern

fn internal_named_graphs( &self, ) -> impl Iterator<Item = Result<Term>> + use<'a, G>

Fetches the list of dataset named graphs

fn contains_internal_graph_name(&self, graph: &Term) -> Result<bool>

Returns if the dataset contains a given named graph

fn internalize_term(&self, term: Term) -> Result<Term>

Builds an internal term from the [Term] struct

fn externalize_term(&self, term: Term) -> Result<Term>

Builds a [Term] from an internal term

fn externalize_expression_term( &self, term: Self::InternalTerm, ) -> Result<ExpressionTerm, Self::Error>

Builds an [ExpressionTerm] from an internal term

fn internalize_expression_term( &self, term: ExpressionTerm, ) -> Result<Self::InternalTerm, Self::Error>

Builds an internal term from an [ExpressionTerm]

fn internal_term_effective_boolean_value( &self, term: Self::InternalTerm, ) -> Result<Option<bool>, Self::Error>

Computes the term Effective boolean value