[−][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 |