use-locale

use-locale provides composable locale identifier primitives for RustUse.

It is a RustUse crate set for identifying, parsing, validating, normalizing, comparing, and composing locale-related identifiers without adopting a full localization framework.

Workspace crates

• use-locale: thin facade crate that reexports the focused crates with a shared prelude
• use-locale-tag: BCP 47 / Unicode-style locale tag parsing and normalization primitives
• use-language: language subtag primitives
• use-script: writing script subtag primitives
• use-region: region subtag primitives for locale identifiers
• use-currency-code: ISO 4217-style currency code primitives
• use-time-zone-id: IANA time zone identifier syntax primitives
• use-timezone: time zone and fixed UTC/GMT offset primitives
• use-locale-match: locale preference and fallback primitives

What it is useful for

• Validating locale tags.
• Normalizing language, script, and region subtags.
• Handling currency code identifiers.
• Handling time zone ID identifiers.
• Handling fixed UTC/GMT offsets.
• Building simple locale fallback chains.
• Composing locale-aware systems without adopting a full i18n framework.

Umbrella crate

Use use-locale when you want a single dependency for the full set.

use use_locale::prelude::{best_locale_match, normalize_locale_tag, parse_currency_code};

assert_eq!(normalize_locale_tag("zh-hant-tw"), Some("zh-Hant-TW".to_string()));
assert_eq!(parse_currency_code("usd").unwrap().as_str(), "USD");
assert_eq!(best_locale_match("en-US", ["en", "fr"]).unwrap().available, "en");

Scope

use-locale focuses on small identifier primitives grounded in BCP 47 language tags, Unicode CLDR/LDML locale concepts, ISO country and currency code shapes, IANA time zone identifier shapes, and fixed UTC/GMT offset shapes.

It intentionally performs syntax validation and casing normalization only. It does not ship CLDR, IANA tzdb, ISO registry snapshots, exchange-rate data, or language metadata databases.

Non-goals

This repository is not:

• A translation framework.
• A CLDR runtime.
• An ICU replacement.
• A date/time library.
• A money library.
• A geocoding system.
• A full web negotiation library.

It also avoids translation catalogs, message formatting, language detection, NLP, currency formatting, time-zone offset calculation, daylight-saving rules, HTTP framework integration, network calls, build-time downloads, generated service data, and global runtime assumptions.

License

Licensed under either of the following, at your option:

• Apache License, Version 2.0
• MIT license