icu_locid/extensions/unicode/
key.rs

1// This file is part of ICU4X. For terms of use, please see the file
2// called LICENSE at the top level of the ICU4X source tree
3// (online at: https://github.com/unicode-org/icu4x/blob/main/LICENSE ).
4
5impl_tinystr_subtag!(
6    /// A key used in a list of [`Keywords`](super::Keywords).
7    ///
8    /// The key has to be a two ASCII alphanumerical characters long, with the first
9    /// character being alphanumeric, and the second being alphabetic.
10    ///
11    ///
12    /// # Examples
13    ///
14    /// ```
15    /// use icu::locid::extensions::unicode::Key;
16    ///
17    /// assert!("ca".parse::<Key>().is_ok());
18    /// ```
19    Key,
20    extensions::unicode,
21    key,
22    extensions_unicode_key,
23    2..=2,
24    s,
25    s.all_bytes()[0].is_ascii_alphanumeric() && s.all_bytes()[1].is_ascii_alphabetic(),
26    s.to_ascii_lowercase(),
27    (s.all_bytes()[0].is_ascii_lowercase() || s.all_bytes()[0].is_ascii_digit())
28        && s.all_bytes()[1].is_ascii_lowercase(),
29    InvalidExtension,
30    ["ca", "8a"],
31    ["a", "a8", "abc"],
32);