# icu_locid [![crates.io](https://img.shields.io/crates/v/icu_locid)](https://crates.io/crates/icu_locid)

Parsing, manipulating, and serializing Unicode Language and Locale Identifiers.

This module is published as its own crate ([`icu_locid`](https://docs.rs/icu_locid/latest/icu_locid/))
and as part of the [`icu`](https://docs.rs/icu/latest/icu/) crate. See the latter for more details on the ICU4X project.

The module provides algorithms for parsing a string into a well-formed language or locale identifier
as defined by [`UTS #35: Unicode LDML 3. Unicode Language and Locale Identifiers`].

[`Locale`] is the most common structure to use for storing information about a language,
script, region, variants and extensions. In almost all cases, this struct should be used as the
base unit for all locale management operations.

[`LanguageIdentifier`] is a strict subset of [`Locale`] which can be useful in a narrow range of
cases where [`Unicode Extensions`] are not relevant.

If in doubt, use [`Locale`].

## Examples

```rust
use icu::locid::subtags::{Language, Region};
use icu::locid::Locale;

let mut loc: Locale = "en-US".parse().expect("Parsing failed.");

let lang: Language = "en".parse().expect("Parsing failed.");
let region: Region = "US".parse().expect("Parsing failed.");

assert_eq!(loc.id.language, lang);
assert_eq!(loc.id.script, None);
assert_eq!(loc.id.region, Some(region));
assert_eq!(loc.id.variants.len(), 0);

let region: Region = "GB".parse().expect("Parsing failed.");
loc.id.region = Some(region);

assert_eq!(loc.to_string(), "en-GB");
```

### Macros

```rust
use icu::locid::{
    langid, subtags_language as language, subtags_region as region,
};

let lid = langid!("EN_US");

assert_eq!(lid.language, language!("en"));
assert_eq!(lid.region, Some(region!("US")));
```

For more details, see [`Locale`] and [`LanguageIdentifier`].

[`UTS #35: Unicode LDML 3. Unicode Language and Locale Identifiers`]: https://unicode.org/reports/tr35/tr35.html#Unicode_Language_and_Locale_Identifiers
[`ICU4X`]: ../icu/index.html
[`Unicode Extensions`]: extensions

## More Information

For more information on development, authorship, contributing etc. please visit [`ICU4X home page`](https://github.com/unicode-org/icu4x).