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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
use super::Attribute;
use crate::shortvec::ShortBoxSlice;
use alloc::vec::Vec;
use core::ops::Deref;
/// A set of [`Attribute`] elements as defined in [`Unicode Extension Attributes`].
///
///
/// # Examples
///
/// ```
/// use icu::locid::extensions::unicode::{Attribute, Attributes};
///
/// let attribute1: Attribute =
/// "foobar".parse().expect("Failed to parse a variant subtag.");
///
/// let attribute2: Attribute = "testing"
/// .parse()
/// .expect("Failed to parse a variant subtag.");
/// let mut v = vec![attribute1, attribute2];
/// v.sort();
/// v.dedup();
///
/// let attributes: Attributes = Attributes::from_vec_unchecked(v);
/// assert_eq!(attributes.to_string(), "foobar-testing");
/// ```
#[derive(Default, Debug, PartialEq, Eq, Clone, Hash, PartialOrd, Ord)]
pub struct Attributes(ShortBoxSlice<Attribute>);
impl Attributes {
/// Returns a new empty set of attributes. Same as [`default()`](Default::default()), but is `const`.
///
/// # Examples
///
/// ```
/// use icu::locid::extensions::unicode::Attributes;
///
/// assert_eq!(Attributes::new(), Attributes::default());
/// ```
#[inline]
pub const fn new() -> Self {
Self(ShortBoxSlice::new())
}
/// A constructor which takes a pre-sorted list of [`Attribute`] elements.
///
///
/// # Examples
///
/// ```
/// use icu::locid::extensions::unicode::{Attribute, Attributes};
///
/// let attribute1: Attribute = "foobar".parse().expect("Parsing failed.");
/// let attribute2: Attribute = "testing".parse().expect("Parsing failed.");
/// let mut v = vec![attribute1, attribute2];
/// v.sort();
/// v.dedup();
///
/// let attributes = Attributes::from_vec_unchecked(v);
/// ```
///
/// Notice: For performance- and memory-constrained environments, it is recommended
/// for the caller to use [`binary_search`](slice::binary_search) instead of [`sort`](slice::sort)
/// and [`dedup`](Vec::dedup()).
pub fn from_vec_unchecked(input: Vec<Attribute>) -> Self {
Self(input.into())
}
pub(crate) fn from_short_slice_unchecked(input: ShortBoxSlice<Attribute>) -> Self {
Self(input)
}
/// Empties the [`Attributes`] list.
///
/// Returns the old list.
///
/// # Examples
///
/// ```
/// use icu::locid::extensions::unicode::{attribute, Attributes};
/// use writeable::assert_writeable_eq;
///
/// let mut attributes = Attributes::from_vec_unchecked(vec![
/// attribute!("foobar"),
/// attribute!("testing"),
/// ]);
///
/// assert_writeable_eq!(attributes, "foobar-testing");
///
/// attributes.clear();
///
/// assert_writeable_eq!(attributes, "");
/// ```
pub fn clear(&mut self) -> Self {
core::mem::take(self)
}
pub(crate) fn for_each_subtag_str<E, F>(&self, f: &mut F) -> Result<(), E>
where
F: FnMut(&str) -> Result<(), E>,
{
self.deref().iter().map(|t| t.as_str()).try_for_each(f)
}
}
impl_writeable_for_subtag_list!(Attributes, "foobar", "testing");
impl Deref for Attributes {
type Target = [Attribute];
fn deref(&self) -> &[Attribute] {
self.0.deref()
}
}