Crate iref_enum 

This is a companion crate for iref providing a derive macro to declare enum types that converts into/from IRIs.

Storage and comparison of IRIs can be costly. One may prefer the use of an enum type representing known IRIs with cheap conversion functions between the two. This crate provides a way to declare such enums in an simple way through the use of a IriEnum derive macro. This macro will implement TryFrom<&Iri> and AsRef<Iri> for you.

Basic usage

Use #[derive(IriEnum)] attribute to generate the implementation of TryFrom<&Iri> and AsRef<Iri> for the enum type. The IRI of each variant is defined with the iri attribute:

use iref_enum::IriEnum;

#[derive(IriEnum, PartialEq, Debug)]
pub enum Vocab {
  #[iri("https://schema.org/name")] Name,
  #[iri("https://schema.org/knows")] Knows
}

let term: Vocab = static_iref::iri!("https://schema.org/name").try_into().unwrap();
assert_eq!(term, Vocab::Name)

Each variant must have at most one parameter. If it has a parameter, its type must implement TryFrom<&Iri> and AsRef<Iri>.

Compact IRIs

The derive macro also support compact IRIs using the special iri_prefix attribute. First declare a prefix associated to a given IRI. Then any iri attribute of the form prefix:suffix we be expanded into the concatenation of the prefix IRI and suffix.

#[derive(IriEnum)]
#[iri_prefix("schema" = "https://schema.org/")]
pub enum Vocab {
  #[iri("schema:name")] Name,
  #[iri("schema:knows")] Knows
}

Derive Macros

IriEnum