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Diffstat (limited to 'third_party/rust/unic-langid/src/lib.rs')
| -rw-r--r-- | third_party/rust/unic-langid/src/lib.rs | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/third_party/rust/unic-langid/src/lib.rs b/third_party/rust/unic-langid/src/lib.rs new file mode 100644 index 0000000000..f66fb444a3 --- /dev/null +++ b/third_party/rust/unic-langid/src/lib.rs @@ -0,0 +1,136 @@ +//! `unic-langid` is a core API for parsing, manipulating, and serializing Unicode Language +//! Identifiers. +//! +//! The crate provides algorithms for parsing a string into a well-formed language identifier +//! as defined by [`UTS #35: Unicode LDML 3.1 Unicode Language Identifier`]. +//! +//! # Examples +//! +//! ``` +//! use unic_langid::LanguageIdentifier; +//! use unic_langid::subtags::{Language, Script, Region}; +//! +//! let mut li: LanguageIdentifier = "en-US".parse() +//! .expect("Parsing failed."); +//! +//! let lang: Language = "en".parse().expect("Parsing failed."); +//! let region: Region = "US".parse().expect("Parsing failed."); +//! assert_eq!(li.language, lang); +//! assert_eq!(li.script, None); +//! assert_eq!(li.region, Some(region)); +//! assert_eq!(li.variants().len(), 0); +//! +//! let region: Region = "GB".parse().expect("Parsing failed."); +//! li.region = Some(region); +//! +//! assert_eq!(li.to_string(), "en-GB"); +//! ``` +//! +//! For more details, see [`LanguageIdentifier`]. +//! +//! # Optional features +//! +//! ## `langid!`, `langids!`, and `langid_slice!` macros +//! +//! If `feature = "macros"` is selected, the crate provides a procedural macro +//! which allows to construct build-time well-formed language identifiers with zero-cost at runtime. +//! +//! ``` ignore +//! use unic_langid::{langid, langid_slice, langids, lang, region, script, variant, LanguageIdentifier}; +//! use unic_langid::subtags::{Language, Script, Region, Variant}; +//! use std::str::FromStr; +//! +//! let es_ar = langid!("es-AR"); +//! let en_us = langid!("en-US"); +//! +//! assert_eq!(&es_ar.to_string(), "es-AR"); +//! assert_eq!(&en_us.to_string(), "en-US"); +//! +//! let lang_ids = langids!("es-AR", "en-US", "de"); +//! +//! assert_eq!(lang_ids[0], "es-AR"); +//! assert_eq!(lang_ids[1], "en-US"); +//! assert_eq!(lang_ids[2], "de"); +//! +//! const LANGUAGES: &[LanguageIdentifier] = langid_slice!["en-GB", "fr"]; +//! +//! assert_eq!(lang!("pl"), "pl"); +//! assert_eq!(lang!("pl"), Language::from_str("pl").unwrap()); +//! +//! assert_eq!(script!("latn"), "Latn"); +//! assert_eq!(script!("latn"), Script::from_str("Latn").unwrap()); +//! +//! assert_eq!(region!("us"), "US"); +//! assert_eq!(region!("us"), Region::from_str("us").unwrap()); +//! +//! assert_eq!(variant!("macos"), "macos"); +//! assert_eq!(variant!("macos"), Variant::from_str("macos").unwrap()); +//! ``` +//! +//! The macros produce instances of `LanguageIdentifier` the same way as parsing from `&str` does, +//! but since the parsing is performed at build time, it doesn't need a `Result`. +//! +//! At the moment `langid!` can also be used for const variables, but only if no variants are used. +//! +//! The macros are optional to reduce the dependency chain and compilation time of `unic-langid`. +//! +//! ## Likely Subtags +//! +//! If `feature = "likelysubtags"` is selected, the `LanguageIdentifier` gains two more methods: +//! +//! * add_likely_subtags +//! * remove_likely_subtags +//! +//! Both of them operate in place updating the existing `LanguageIdentifier` by either extending +//! subtags to most likely values, or removing the subtags that are not needed. +//! +//! Both methods return a `bool` that indicates if the identifier has been modified. +//! +//! ``` ignore +//! use unic_langid::LanuageIdentifier; +//! +//! let mut li: LanguageIdentifier = "fr-FR".parse() +//! .expect("Parsing failed."); +//! +//! assert_eq!(li.add_likely_subtags(), true); +//! assert_eq!(li, "fr-Latn-FR"); +//! +//! assert_eq!(li.remove_likely_subtags(), true); +//! assert_eq!(li, "fr"); +//! ``` +//! +//! The feature is optional because it increases the binary size of the library by including +//! a data table for CLDR likelySubtags. +//! +//! [`UTS #35: Unicode LDML 3.1 Unicode Language Identifier`]: https://unicode.org/reports/tr35/tr35.html#Unicode_language_identifier +//! [`LanguageIdentifier`]: ./struct.LanguageIdentifier.html + +pub use unic_langid_impl::*; + +#[cfg(feature = "unic-langid-macros")] +pub use unic_langid_macros::{lang, langid, region, script, variant}; + +#[cfg(feature = "unic-langid-macros")] +#[macro_export] +macro_rules! langids { + ( $($langid:expr),* ) => { + vec![$( + $crate::langid!($langid), + )*] + }; + ( $($langid:expr,)* ) => { + $crate::langids![$($langid),*] + }; +} +#[cfg(feature = "unic-langid-macros")] +#[macro_export] +macro_rules! langid_slice { + ( $($langid:expr),* ) => { + &[$( + $crate::langid!($langid), + )*] + }; + ( $($langid:expr,)* ) => { + $crate::langid_slice![$($langid),*] + }; +} |