Module @metreeca/keep-sparql - v0.12.2

SPARQL 1.1 repository connector.

Turns any SPARQL 1.1 Repository into a fully featured Store, so shape-driven retrieval and persistence run against a graph backend without hand-written queries. A ready-made connector from the @metreeca/wire collection (Oxigraph, generic HTTP endpoints, RDF4J, …) covers the common backends; a new backend is supported by implementing Repository directly.

Wiring a Connector

A ready-made connector is passed to createSPARQLStore to obtain a store:

import { createSPARQLStore } from "@metreeca/keep-sparql";
import { createOxiRepository } from "@metreeca/wire-sparql-oxigraph";

const store = createSPARQLStore(createOxiRepository());

await store.create({
    entry: "http://example.com/products/",
    shape: CatalogueShape,
    model: { products: {} },
    state: { name: "Widget", price: 9.99 }
});
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Implementing a Connector

A new SPARQL backend is supported by implementing a Repository. The repository exchanges SPARQL text and Tuple solution rows, whose values are @metreeca/trio Term values. Backend node values are lifted into terms with the named, tagged and typed constructors. The reference implementation in @metreeca/wire-sparql-oxigraph follows this pattern:

import { named, tagged, type Term, typed } from "@metreeca/trio";
import { type Repository } from "@metreeca/wire-sparql";

function decode(node: BackendNode): Term {
    return node.kind === "iri" ? named(node.iri)
        : node.kind === "language" ? tagged(node.text, node.language)
            : typed(node.text, node.datatype);
}

export function createMyRepository(): Repository {
    // ... satisfy ask/select/construct/update/execute/close against the backend
}
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