Function lift_ref

atomic-canonical/src/lift.rs:232–253

Lift a `:::ref{to= edge=}` leaf into a typed dependency edge. Both `to` and `edge` are required (a dependency with no target or no edge type is a lift error), and `edge` must be a known *dependency* edge — a `:::ref` sits on the dependency chain, so edges like `verifiedBy`/`about` are rejected even though they are valid edges elsewhere.

(d: &Directive)

/// dependency chain, so edges like `verifiedBy`/`about` are rejected even though
/// they are valid edges elsewhere.
fn lift_ref(d: &Directive) -> Result<Ref> {
    let to = d
        .attr("to")
        .ok_or_else(|| CanonicalError::Lift("':::ref' is missing required 'to'".into()))?
        .to_string();
    let edge = d
        .attr("edge")
        .ok_or_else(|| CanonicalError::Lift("':::ref' is missing required 'edge'".into()))?
        .to_string();
    if !vocab::is_known_dependency_edge(&edge) {
        return Err(CanonicalError::Lift(format!(
            "':::ref' edge '{edge}' is not a dependency edge {:?}",
            vocab::DEPENDENCY_EDGES
        )));
    }
    Ok(Ref {
        type_: d.id.as_ref().map(|_| NodeType::Ref.as_str().to_string()),
        id: d.id.as_ref().map(|id| as_urn("ref", id)),
        to,
        edge,
    })
}

/// Wrap a local id into `urn:atomic:<kind>:<local>` unless already a urn.
fn as_urn(kind: &str, local: &str) -> String {