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// 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
//! Other Use Extensions is a list of extensions other than unicode,
//! transform or private.
//!
//! Those extensions are treated as a pass-through, and no Unicode related
//! behavior depends on them.
//!
//! The main struct for this extension is [`Other`] which is a list of [`Subtag`]s.
//!
//! # Examples
//!
//! ```
//! use icu::locid::extensions::other::Other;
//! use icu::locid::Locale;
//!
//! let mut loc: Locale = "en-US-a-foo-faa".parse().expect("Parsing failed.");
//! ```
mod subtag;
use crate::parser::ParserError;
use crate::parser::SubtagIterator;
use crate::shortvec::ShortBoxSlice;
use alloc::vec::Vec;
#[doc(inline)]
pub use subtag::{subtag, Subtag};
/// A list of [`Other Use Extensions`] as defined in [`Unicode Locale
/// Identifier`] specification.
///
/// Those extensions are treated as a pass-through, and no Unicode related
/// behavior depends on them.
///
/// # Examples
///
/// ```
/// use icu::locid::extensions::other::{Other, Subtag};
///
/// let subtag1: Subtag = "foo".parse().expect("Failed to parse a Subtag.");
/// let subtag2: Subtag = "bar".parse().expect("Failed to parse a Subtag.");
///
/// let other = Other::from_vec_unchecked(b'a', vec![subtag1, subtag2]);
/// assert_eq!(&other.to_string(), "a-foo-bar");
/// ```
///
#[derive(Clone, PartialEq, Eq, Debug, Default, Hash, PartialOrd, Ord)]
pub struct Other {
ext: u8,
keys: ShortBoxSlice<Subtag>,
}
impl Other {
/// A constructor which takes a pre-sorted list of [`Subtag`].
///
/// # Panics
///
/// Panics if `ext` is not ASCII alphabetic.
///
/// # Examples
///
/// ```
/// use icu::locid::extensions::other::{Other, Subtag};
///
/// let subtag1: Subtag = "foo".parse().expect("Failed to parse a Subtag.");
/// let subtag2: Subtag = "bar".parse().expect("Failed to parse a Subtag.");
///
/// let other = Other::from_vec_unchecked(b'a', vec![subtag1, subtag2]);
/// assert_eq!(&other.to_string(), "a-foo-bar");
/// ```
pub fn from_vec_unchecked(ext: u8, keys: Vec<Subtag>) -> Self {
Self::from_short_slice_unchecked(ext, keys.into())
}
pub(crate) fn from_short_slice_unchecked(ext: u8, keys: ShortBoxSlice<Subtag>) -> Self {
assert!(ext.is_ascii_alphabetic());
Self { ext, keys }
}
pub(crate) fn try_from_iter(ext: u8, iter: &mut SubtagIterator) -> Result<Self, ParserError> {
debug_assert!(ext.is_ascii_alphabetic());
let mut keys = ShortBoxSlice::new();
while let Some(subtag) = iter.peek() {
if !Subtag::valid_key(subtag) {
break;
}
if let Ok(key) = Subtag::try_from_bytes(subtag) {
keys.push(key);
}
iter.next();
}
Ok(Self::from_short_slice_unchecked(ext, keys))
}
/// Gets the tag character for this extension as a &str.
///
/// # Examples
///
/// ```
/// use icu::locid::Locale;
///
/// let loc: Locale = "und-a-hello-world".parse().unwrap();
/// let other_ext = &loc.extensions.other[0];
/// assert_eq!(other_ext.get_ext_str(), "a");
/// ```
pub fn get_ext_str(&self) -> &str {
debug_assert!(self.ext.is_ascii_alphabetic());
unsafe { core::str::from_utf8_unchecked(core::slice::from_ref(&self.ext)) }
}
/// Gets the tag character for this extension as a char.
///
/// # Examples
///
/// ```
/// use icu::locid::Locale;
///
/// let loc: Locale = "und-a-hello-world".parse().unwrap();
/// let other_ext = &loc.extensions.other[0];
/// assert_eq!(other_ext.get_ext(), 'a');
/// ```
pub fn get_ext(&self) -> char {
self.ext as char
}
/// Gets the tag character for this extension as a byte.
///
/// # Examples
///
/// ```
/// use icu::locid::Locale;
///
/// let loc: Locale = "und-a-hello-world".parse().unwrap();
/// let other_ext = &loc.extensions.other[0];
/// assert_eq!(other_ext.get_ext_byte(), b'a');
/// ```
pub fn get_ext_byte(&self) -> u8 {
self.ext
}
pub(crate) fn for_each_subtag_str<E, F>(&self, f: &mut F) -> Result<(), E>
where
F: FnMut(&str) -> Result<(), E>,
{
f(self.get_ext_str())?;
self.keys.iter().map(|t| t.as_str()).try_for_each(f)
}
}
writeable::impl_display_with_writeable!(Other);
impl writeable::Writeable for Other {
fn write_to<W: core::fmt::Write + ?Sized>(&self, sink: &mut W) -> core::fmt::Result {
sink.write_str(self.get_ext_str())?;
for key in self.keys.iter() {
sink.write_char('-')?;
writeable::Writeable::write_to(key, sink)?;
}
Ok(())
}
fn writeable_length_hint(&self) -> writeable::LengthHint {
let mut result = writeable::LengthHint::exact(1);
for key in self.keys.iter() {
result += writeable::Writeable::writeable_length_hint(key) + 1;
}
result
}
fn write_to_string(&self) -> alloc::borrow::Cow<str> {
if self.keys.is_empty() {
return alloc::borrow::Cow::Borrowed(self.get_ext_str());
}
let mut string =
alloc::string::String::with_capacity(self.writeable_length_hint().capacity());
let _ = self.write_to(&mut string);
alloc::borrow::Cow::Owned(string)
}
}