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Diffstat (limited to 'vendor/icu_locid/src/extensions/mod.rs')
-rw-r--r-- | vendor/icu_locid/src/extensions/mod.rs | 313 |
1 files changed, 313 insertions, 0 deletions
diff --git a/vendor/icu_locid/src/extensions/mod.rs b/vendor/icu_locid/src/extensions/mod.rs new file mode 100644 index 000000000..42bfcd3c9 --- /dev/null +++ b/vendor/icu_locid/src/extensions/mod.rs @@ -0,0 +1,313 @@ +// This file is part of ICU4X. For terms of use, please see the file +// called LICENSE at the top level of the ICU4X source tree +// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ). + +//! Unicode Extensions provide a mechanism to extend the [`LanguageIdentifier`] with +//! additional bits of information - a combination of a [`LanguageIdentifier`] and [`Extensions`] +//! is called [`Locale`]. +//! +//! There are four types of extensions: +//! +//! * [`Unicode Extensions`] - marked as `u`. +//! * [`Transform Extensions`] - marked as `t`. +//! * [`Private Use Extensions`] - marked as `x`. +//! * [`Other Extensions`] - marked as any `a-z` except of `u`, `t` and `x`. +//! +//! One can think of extensions as a bag of extra information on top of basic 4 [`subtags`]. +//! +//! Notice: `Other` extension type is currently not supported. +//! +//! # Examples +//! +//! ``` +//! use icu::locid::extensions::unicode::{Key, Value}; +//! use icu::locid::Locale; +//! +//! let loc: Locale = "en-US-u-ca-buddhist-t-en-US-h0-hybrid-x-foo" +//! .parse() +//! .expect("Failed to parse."); +//! +//! assert_eq!(loc.id.language, "en".parse().unwrap()); +//! assert_eq!(loc.id.script, None); +//! assert_eq!(loc.id.region, Some("US".parse().unwrap())); +//! assert_eq!(loc.id.variants.len(), 0); +//! +//! let key: Key = "ca".parse().expect("Parsing key failed."); +//! let value: Value = "buddhist".parse().expect("Parsing value failed."); +//! assert_eq!(loc.extensions.unicode.keywords.get(&key), Some(&value)); +//! ``` +//! +//! [`LanguageIdentifier`]: super::LanguageIdentifier +//! [`Locale`]: super::Locale +//! [`subtags`]: super::subtags +//! [`Other Extensions`]: other +//! [`Private Use Extensions`]: private +//! [`Transform Extensions`]: transform +//! [`Unicode Extensions`]: unicode +pub mod other; +pub mod private; +pub mod transform; +pub mod unicode; + +use other::Other; +use private::Private; +use transform::Transform; +use unicode::Unicode; + +use alloc::vec::Vec; + +use crate::parser::ParserError; +use crate::parser::SubtagIterator; + +/// Defines the type of extension. +#[derive(Debug, PartialEq, Eq, Clone, Hash, PartialOrd, Ord, Copy)] +#[non_exhaustive] +pub enum ExtensionType { + /// Transform Extension Type marked as `t`. + Transform, + /// Unicode Extension Type marked as `u`. + Unicode, + /// Private Extension Type marked as `x`. + Private, + /// All other extension types. + Other(u8), +} + +impl ExtensionType { + pub(crate) const fn try_from_byte(key: u8) -> Result<Self, ParserError> { + let key = key.to_ascii_lowercase(); + match key { + b'u' => Ok(Self::Unicode), + b't' => Ok(Self::Transform), + b'x' => Ok(Self::Private), + b'a'..=b'z' => Ok(Self::Other(key)), + _ => Err(ParserError::InvalidExtension), + } + } + + pub(crate) const fn try_from_bytes_manual_slice( + bytes: &[u8], + start: usize, + end: usize, + ) -> Result<Self, ParserError> { + if end - start != 1 { + return Err(ParserError::InvalidExtension); + } + #[allow(clippy::indexing_slicing)] + Self::try_from_byte(bytes[start]) + } +} + +/// A map of extensions associated with a given [`Locale`](crate::Locale). +#[derive(Debug, Default, PartialEq, Eq, Clone, Hash)] +#[non_exhaustive] +pub struct Extensions { + /// A representation of the data for a Unicode extension, when present in the locale identifer. + pub unicode: Unicode, + /// A representation of the data for a transform extension, when present in the locale identifer. + pub transform: Transform, + /// A representation of the data for a private-use extension, when present in the locale identifer. + pub private: Private, + /// A sequence of any other extensions that are present in the locale identifier but are not formally + /// [defined](https://unicode.org/reports/tr35/) and represented explicitly as [`Unicode`], [`Transform`], + /// and [`Private`] are. + pub other: Vec<Other>, +} + +impl Extensions { + /// Returns a new empty map of extensions. Same as [`default()`](Default::default()), but is `const`. + /// + /// # Examples + /// + /// ``` + /// use icu::locid::extensions::Extensions; + /// + /// assert_eq!(Extensions::new(), Extensions::default()); + /// ``` + #[inline] + pub const fn new() -> Self { + Self { + unicode: Unicode::new(), + transform: Transform::new(), + private: Private::new(), + other: Vec::new(), + } + } + + /// Function to create a new map of extensions containing exactly one unicode extension, callable in `const` + /// context. + #[inline] + pub const fn from_unicode(unicode: Unicode) -> Self { + Self { + unicode, + transform: Transform::new(), + private: Private::new(), + other: Vec::new(), + } + } + + /// Returns whether there are no extensions present. + /// + /// # Examples + /// + /// ``` + /// use icu::locid::Locale; + /// + /// let loc: Locale = "en-US-u-foo".parse().expect("Parsing failed."); + /// + /// assert!(!loc.extensions.is_empty()); + /// ``` + pub fn is_empty(&self) -> bool { + self.unicode.is_empty() + && self.transform.is_empty() + && self.private.is_empty() + && self.other.is_empty() + } + + /// Retains the specified extension types, clearing all others. + /// + /// # Examples + /// + /// ``` + /// use icu::locid::extensions::ExtensionType; + /// use icu::locid::Locale; + /// + /// let loc: Locale = + /// "und-a-hello-t-mul-u-world-z-zzz-x-extra".parse().unwrap(); + /// + /// let mut only_unicode = loc.clone(); + /// only_unicode + /// .extensions + /// .retain_by_type(|t| t == ExtensionType::Unicode); + /// assert_eq!(only_unicode, "und-u-world".parse().unwrap()); + /// + /// let mut only_t_z = loc.clone(); + /// only_t_z.extensions.retain_by_type(|t| { + /// t == ExtensionType::Transform || t == ExtensionType::Other(b'z') + /// }); + /// assert_eq!(only_t_z, "und-t-mul-z-zzz".parse().unwrap()); + /// ``` + pub fn retain_by_type<F>(&mut self, mut predicate: F) + where + F: FnMut(ExtensionType) -> bool, + { + if !predicate(ExtensionType::Unicode) { + self.unicode.clear(); + } + if !predicate(ExtensionType::Transform) { + self.transform.clear(); + } + if !predicate(ExtensionType::Private) { + self.private.clear(); + } + self.other + .retain(|o| predicate(ExtensionType::Other(o.get_ext_byte()))); + } + + pub(crate) fn try_from_iter(iter: &mut SubtagIterator) -> Result<Self, ParserError> { + let mut unicode = None; + let mut transform = None; + let mut private = None; + let mut other = Vec::new(); + + let mut st = iter.next(); + while let Some(subtag) = st { + match subtag.get(0).map(|b| ExtensionType::try_from_byte(*b)) { + Some(Ok(ExtensionType::Unicode)) => { + unicode = Some(Unicode::try_from_iter(iter)?); + } + Some(Ok(ExtensionType::Transform)) => { + transform = Some(Transform::try_from_iter(iter)?); + } + Some(Ok(ExtensionType::Private)) => { + private = Some(Private::try_from_iter(iter)?); + } + Some(Ok(ExtensionType::Other(ext))) => { + let parsed = Other::try_from_iter(ext, iter)?; + if let Err(idx) = other.binary_search(&parsed) { + other.insert(idx, parsed); + } else { + return Err(ParserError::InvalidExtension); + } + } + None => {} + _ => return Err(ParserError::InvalidExtension), + } + + st = iter.next(); + } + + Ok(Self { + unicode: unicode.unwrap_or_default(), + transform: transform.unwrap_or_default(), + private: private.unwrap_or_default(), + other, + }) + } + + pub(crate) fn for_each_subtag_str<E, F>(&self, f: &mut F) -> Result<(), E> + where + F: FnMut(&str) -> Result<(), E>, + { + let mut wrote_tu = false; + // Alphabetic by singleton + self.other.iter().try_for_each(|other| { + if other.get_ext() > 't' && !wrote_tu { + // Since 't' and 'u' are next to each other in alphabetical + // order, write both now. + self.transform.for_each_subtag_str(f)?; + self.unicode.for_each_subtag_str(f)?; + wrote_tu = true; + } + other.for_each_subtag_str(f)?; + Ok(()) + })?; + + if !wrote_tu { + self.transform.for_each_subtag_str(f)?; + self.unicode.for_each_subtag_str(f)?; + } + + // Private must be written last, since it allows single character + // keys. Extensions must also be written in alphabetical order, + // which would seem to imply that other extensions `y` and `z` are + // invalid, but this is not specified. + self.private.for_each_subtag_str(f)?; + Ok(()) + } +} + +impl_writeable_for_each_subtag_str_no_test!(Extensions); + +#[test] +fn test_writeable() { + use crate::Locale; + use writeable::assert_writeable_eq; + assert_writeable_eq!(Extensions::new(), "",); + assert_writeable_eq!( + "my-t-my-d0-zawgyi".parse::<Locale>().unwrap().extensions, + "t-my-d0-zawgyi", + ); + assert_writeable_eq!( + "ar-SA-u-ca-islamic-civil" + .parse::<Locale>() + .unwrap() + .extensions, + "u-ca-islamic-civil", + ); + assert_writeable_eq!( + "en-001-x-foo-bar".parse::<Locale>().unwrap().extensions, + "x-foo-bar", + ); + assert_writeable_eq!( + "und-t-m0-true".parse::<Locale>().unwrap().extensions, + "t-m0-true", + ); + assert_writeable_eq!( + "und-a-foo-t-foo-u-foo-w-foo-z-foo-x-foo" + .parse::<Locale>() + .unwrap() + .extensions, + "a-foo-t-foo-u-foo-w-foo-z-foo-x-foo", + ); +} |