pub trait Id: AsIri + Clone + PartialEq + Eq + Hash {
fn from_iri(iri: Iri<'_>) -> Self;
fn as_json<K: JsonBuild>(&self, meta: K::MetaData) -> K { ... }
}Expand description
Unique identifier types.
While JSON-LD uses Internationalized Resource Identifiers (IRIs) to uniquely identify each node, this crate does not imposes the internal representation of identifiers.
Whatever type you choose, it must implement this trait to usure that:
- there is a low cost bijection with IRIs,
- it can be cloned (
Clone), - it can be compared (
PartialEq,Eq), - it can be hashed (
Hash).
Using enum types
If you know in advance which IRIs will be used by your implementation,
one possibility is to use a enum type as identifier.
This can be done throught the use of the Lexicon type along with the
iref-enum crate:
use iref_enum::*;
use json_ld::Lexicon;
use serde_json::Value;
/// Vocabulary used in the implementation.
#[derive(IriEnum, Clone, Copy, PartialEq, Eq, Hash)]
#[iri_prefix("rdfs" = "http://www.w3.org/2000/01/rdf-schema#")]
#[iri_prefix("manifest" = "http://www.w3.org/2001/sw/DataAccess/tests/test-manifest#")]
#[iri_prefix("vocab" = "https://w3c.github.io/json-ld-api/tests/vocab#")]
pub enum Vocab {
#[iri("rdfs:comment")] Comment,
#[iri("manifest:name")] Name,
#[iri("manifest:entries")] Entries,
#[iri("manifest:action")] Action,
#[iri("manifest:result")] Result,
#[iri("vocab:PositiveEvaluationTest")] PositiveEvalTest,
#[iri("vocab:NegativeEvaluationTest")] NegativeEvalTest,
#[iri("vocab:option")] Option,
#[iri("vocab:specVersion")] SpecVersion,
#[iri("vocab:processingMode")] ProcessingMode,
#[iri("vocab:expandContext")] ExpandContext,
#[iri("vocab:base")] Base
}
/// A fully functional identifier type.
pub type Id = Lexicon<Vocab>;
fn handle_node(node: &json_ld::Node<Value, Id>) {
for name in node.get(Vocab::Name) { // <- note that we can directly use `Vocab` here.
println!("node name: {}", name.as_str().unwrap());
}
}