// 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 region subtag (examples: `"US"`, `"CN"`, `"AR"` etc.)
    ///
    /// [`Region`] represents a Unicode base language code conformat to the
    /// [`unicode_region_id`] field of the Language and Locale Identifier.
    ///
    /// # Examples
    ///
    /// ```
    /// use icu::locid::subtags::Region;
    ///
    /// let region: Region =
    ///     "DE".parse().expect("Failed to parse a region subtag.");
    /// ```
    ///
    /// [`unicode_region_id`]: https://unicode.org/reports/tr35/#unicode_region_id
    Region,
    subtags::Region,
    subtags_region,
    2..=3,
    s,
    if s.len() == 2 {
        s.is_ascii_alphabetic()
    } else {
        s.is_ascii_numeric()
    },
    if s.len() == 2 {
        s.to_ascii_uppercase()
    } else {
        s
    },
    if s.len() == 2 {
        s.is_ascii_alphabetic_uppercase()
    } else {
        s.is_ascii_numeric()
    },
    InvalidSubtag,
    ["FR", "123"],
    ["12", "FRA", "b2"],
);

impl Region {
    /// Returns true if the Region has an alphabetic code.
    ///
    /// # Examples
    ///
    /// ```
    /// use icu::locid::subtags::Region;
    ///
    /// let region = Region::try_from_bytes(b"us").expect("Parsing failed.");
    ///
    /// assert!(region.is_alphabetic());
    /// ```
    pub fn is_alphabetic(&self) -> bool {
        self.0.len() == 2
    }
}