Function literal

pub fn literal<RDF>() -> impl RDFNodeParse<RDF, Output = Literal>
where
    RDF: FocusRDF,

Checks if the focus node is an IRI

use iri_s::{IriS, iri};
use srdf::{SRDFGraph, iri, RDFNodeParse};

let graph = SRDFGraph::new();
let x = iri!("http://example.org/x");
assert_eq!(iri().parse(&x, graph).unwrap(), x)