[−][src]Crate iref_enum

IRI Enums

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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 convertion 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 Into<Iri> for you.

Basic usage

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

#[macro_use]
extern crate iref_enum;
use std::convert::TryInto;

#[derive(IriEnum, PartialEq, Debug)]
pub enum Vocab {
	#[iri("http://xmlns.com/foaf/0.1/name")] Name,
	#[iri("http://xmlns.com/foaf/0.1/knows")] Knows
}

pub fn main() {
	let term: Vocab = static_iref::iri!("http://xmlns.com/foaf/0.1/name").try_into().unwrap();
	assert_eq!(term, Vocab::Name)
}

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("foaf" = "http://xmlns.com/foaf/0.1/")]
pub enum Vocab {
	#[iri("foaf:name")] Name,
	#[iri("foaf:knows")] Knows
}

Derive Macros

IriEnum