ld-core

Serialize and deserialize Rust types as Linked Data. Traits describing how a value maps onto RDF subjects, predicates and graphs, plus derive macros that write those impls for you.

use iri_rs::IriBuf;
use ld_core::{Deserialize, Serialize, to_quads};
use ld_core::rdfx::{RdfDisplay, generator};

#[derive(Serialize, Deserialize)]
#[ld(prefix("ex" = "http://example.org/"))]
struct Foo {
    #[ld(id)]
    id: IriBuf,

    #[ld("ex:name")]
    name: String,

    #[ld("ex:email")]
    email: String,
}

let value = Foo {
    id: IriBuf::new("http://example.org/JohnSmith".to_owned()).unwrap(),
    name: "John Smith".to_owned(),
    email: "john.smith@example.org".to_owned(),
};

for quad in to_quads(generator::Blank::new(), &value).unwrap() {
    println!("{} .", quad.rdf_display());
}

<http://example.org/JohnSmith> <http://example.org/name> "John Smith" .
<http://example.org/JohnSmith> <http://example.org/email> "john.smith@example.org" .

Why this fork

Fork of linked-data by Spruce Systems, Inc.. The traits, the derive attributes and the RDF mapping are unchanged; this fork retargets the crate at a different dependency stack:

Renamed crates: linked-data → ld-core, linked-data-derive → ld-core-derive.
Depends on rdfx instead of rdf-types, xsd-rs instead of xsd-types, iri-rs instead of iref / static-iref, and jstrict instead of json-syntax — which is the point of the fork.
RDF 1.2 aware through rdfx: triple terms and directional language strings pass through the quad conversions.
Rust 2024 edition, MSRV 1.85 (upstream: 2021, 1.71.1).
Warning-free build and a reshaped workspace.

Credit and history preserved — see Attribution.

Install

cargo add ld-core

Feature flags

Flag	Default	Enables
`derive`	yes	The `Serialize` / `Deserialize` derive macros (`ld-core-derive`)
`serde`	yes	`serde` interop, including the `json_literal!` macro

Derive attributes

The derive macros read #[ld(...)] attributes:

Attribute	Meaning
`#[ld(prefix("ex" = "..."))]`	Declares a prefix usable in later attributes
`#[ld(type = "...")]`	Emits an `rdf:type` triple for the subject
`#[ld(id)]`	The field holds the subject IRI
`#[ld("ex:name")]`	The field is the object of that predicate
`#[ld(flatten)]`	Merges the field's own properties into the parent subject
`#[ld(graph)]`	The field's quads go into a named graph
`#[ld(ignore)]`	The field takes no part in serialization

See ld-core/examples/ for runnable end-to-end usage:

cargo run --example derive
cargo run --example derive_enum
cargo run --example generics
cargo run --example graph

Interpretations and vocabularies

to_quads produces lexical quads with blank nodes drawn from a generator. When resources are interned — indices from an rdfx vocabulary, say — use the interpreted counterparts instead: to_interpreted_quads, to_interpreted_subject_quads and to_interpreted_graph_quads, which keep values in the interpretation domain rather than materialising IRIs.

MSRV

Rust 1.85 (edition 2024).

Attribution

Original crates: linked-data and linked-data-derive by Spruce Systems, Inc.. Upstream commits are preserved in this repo's history under their original authorship. This fork is a dependency swap onto the rdfx / xsd-rs / iri-rs / jstrict stack, plus edition 2024 polish.

License

Dual-licensed, same as upstream. Pick whichever fits:

ld-core 0.3.0