1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107
// 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 ).
impl_tinystr_subtag!(
/// A language subtag (examples: `"en"`, `"csb"`, `"zh"`, `"und"`, etc.)
///
/// [`Language`] represents a Unicode base language code conformant to the
/// [`unicode_language_id`] field of the Language and Locale Identifier.
///
/// # Examples
///
/// ```
/// use icu::locid::subtags::Language;
///
/// let language: Language =
/// "en".parse().expect("Failed to parse a language subtag.");
/// ```
///
/// If the [`Language`] has no value assigned, it serializes to a string `"und"`, which
/// can be then parsed back to an empty [`Language`] field.
///
/// # Examples
///
/// ```
/// use icu::locid::subtags::Language;
///
/// assert_eq!(Language::default().as_str(), "und");
/// ```
///
/// `Notice`: ICU4X uses a narrow form of language subtag of 2-3 characters.
/// The specification allows language subtag to optionally also be 5-8 characters
/// but that form has not been used and ICU4X does not support it right now.
///
/// [`unicode_language_id`]: https://unicode.org/reports/tr35/#unicode_language_id
Language,
subtags,
language,
subtags_language,
2..=3,
s,
s.is_ascii_alphabetic(),
s.to_ascii_lowercase(),
s.is_ascii_alphabetic_lowercase(),
InvalidLanguage,
["en", "foo"],
["419", "german", "en1"],
);
impl Language {
/// The default undefined language "und". Same as [`default()`](Default::default()).
///
/// # Examples
///
/// ```
/// use icu::locid::subtags::Language;
///
/// assert_eq!(Language::default(), Language::UND);
/// ```
pub const UND: Self = unsafe { Self::from_raw_unchecked(*b"und") };
/// Resets the [`Language`] subtag to an empty one (equal to `"und"`).
///
/// # Examples
///
/// ```
/// use icu::locid::subtags::{language, Language};
///
/// let mut lang = language!("csb");
///
/// assert_ne!(lang, Language::UND);
///
/// lang.clear();
///
/// assert_eq!(lang, Language::UND);
/// ```
#[inline]
pub fn clear(&mut self) {
*self = Self::UND
}
/// Tests if the [`Language`] subtag is empty (equal to `"und"`).
///
/// # Examples
///
/// ```
/// use icu::locid::subtags::Language;
///
/// let mut lang = Language::UND;
///
/// assert!(lang.is_empty());
///
/// lang.clear();
///
/// assert!(lang.is_empty());
/// ```
#[inline]
pub fn is_empty(self) -> bool {
self == Self::UND
}
}
impl Default for Language {
fn default() -> Language {
Language::UND
}
}