Trait PathBackend 

pub trait PathBackend {
    // Required methods
    fn objects(&self, subject: &Term, predicate: &NamedNode) -> HashSet<Term>;
    fn subjects(&self, predicate: &NamedNode, object: &Term) -> HashSet<Term>;
    fn out_predicates(&self, subject: &Term) -> BTreeSet<NamedNode>;
}

Storage backend for path evaluation. Exposes the three adjacency primitives succ/pred/sh:closed need, so path evaluation can dispatch to either a linear oxrdf::Graph or the indexed FrozenIndexedDataset.

Required Methods

fn objects(&self, subject: &Term, predicate: &NamedNode) -> HashSet<Term>

{ o | (subject, predicate, o) ∈ G } — forward step.

fn subjects(&self, predicate: &NamedNode, object: &Term) -> HashSet<Term>

{ s | (s, predicate, object) ∈ G } — backward step.

fn out_predicates(&self, subject: &Term) -> BTreeSet<NamedNode>

Predicates of the outgoing triples of subject (used by sh:closed).

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementations on Foreign Types

impl PathBackend for Graph

Linear backend over oxrdf’s B-tree indexes. Used by inference, whose graph grows during forward chaining and so cannot share an immutable snapshot.

fn objects(&self, subject: &Term, predicate: &NamedNode) -> HashSet<Term>

fn subjects(&self, predicate: &NamedNode, object: &Term) -> HashSet<Term>

fn out_predicates(&self, subject: &Term) -> BTreeSet<NamedNode>

Implementors

impl PathBackend for FrozenIndexedDataset

Indexed backend over the dictionary-encoded post-inference snapshot. Built once at the inference→validation boundary and shared across focus nodes; the u32-keyed sorted indexes replace per-call term hashing and B-tree walks. Unknown terms intern to fresh ids that match no stored triple — exactly the empty-result semantics path evaluation needs.