phrasebook-catalog

The language identifier and message catalog types of phrasebook: Lang, Source and Catalog. They are plain const data, with no dependencies by default and no need for std or alloc.

An app uses them through phrasebook, which re-exports them at its crate root as phrasebook::{Lang, Source, Catalog, ParseLangError}. They live in this crate of their own so that a library's catalog outlives phrasebook's breaking releases: a library such as watchword ships its messages as a pub static L10N: Catalog, and an app hands that catalog to its own phrasebook. Both name this crate's Catalog, which changes far more rarely than phrasebook does, so an app can move to a new phrasebook without waiting for every library it uses to move with it.

A library that only ships a catalog depends on this crate alone, with phrasebook as a dev-dependency for its check helpers in tests. A library whose components read the app's handle depends on phrasebook as well, since that handle, phrasebook's Phrases, is the context type.

Features

None is on by default. Each versioned feature adds trait impls on Lang for a dependency that is not yet 1.0, which phrasebook's feature of the same name turns on; they live here because only the crate that defines Lang may implement another crate's traits for it. A later version of such a dependency is another feature beside it, not a breaking release.

Example

use phrasebook_catalog::{Catalog, Lang, Source};

const SV_SE: Lang = Lang::new("sv-SE");

pub static L10N: Catalog = Catalog::new("watchword", &[
    Source::new(Lang::EN_US, "watchword-sign-in = Sign in"),
    Source::new(SV_SE, "watchword-sign-in = Logga in"),
])
.with_prefix("watchword-");

assert_eq!(L10N.default_lang(), Some(Lang::EN_US));
assert_eq!(L10N.source(SV_SE).map(|s| s.ftl()), Some("watchword-sign-in = Logga in"));