Crate grdf

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Expand description

The Resource Description Framework (RDF) is a powerful method for modeling data and knowledge defined by the World Wide Web Consortium (W3C). A RDF dataset consists in a collection of graphs connecting nodes, values and predicates. This crate provides traits and implementations of Generalized RDF (gRDF) where nodes, values and predicates have the same representation.

Note that this crates requires rust compiler version 1.65 or later. It needs Generic Associated Typed (GAT) to work properly.

Basic usage

Exploring a dataset

Each Dataset implementation provides many iterators to explore the data. One simple way is to iterate through the quad of the dataset:

for Quad(subject, predicate, object, graph) in dataset {
  // do something

Another way is to access each graph individually using Dataset::graph. For a given graph, it is then possible to iterate through the triples of the graph:

let graph = dataset.graph(id).unwrap();

for Triple(subject, predicate, object) in graph {
  // do something

It is also possible to explore the graph logically, subject by subject, predicate by predicate, object by object:

// for each subject of the graph...
for (subject, predicates) in graph.subjects() {
  // for each predicate it is subject...
  for (predicate, objects) in predicates {
    // for each triple (subject, predicate, object)...
    for object in objects {
      // do something

Inserting new data

Insertion can be done on MutableDataset implementations using MutableDataset::insert:

let mut dataset: HashDataset<Term> = HashDataset::new();
dataset.insert(Quad(subject, predicate, object, graph));

Again it is possible to access each graph of the dataset mutably:

let mut graph = dataset.graph_mut(id).unwrap();
graph.insert(Triple(subject, predicate, object));

Custom RDF types

The types used to represent RDF subjects, predicate and objects are parameters of the dataset. Anything can be used although they default to the rdf_types::Term type that represents generic RDF nodes (blank nodes, IRI-named nodes and literal values).




  • Graph implementation based on BTreeMap and BTreeSet.
  • View a graph from the perspective of a single subject resource.
  • Graph implementation based on HashMap and HashSet.
  • Simple GraphAccess implementation for graphs such that Subject = Object.
  • RDF quad.
  • RDF triple.
  • View a dateset from the perspective of a single graph subject resource.