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 | |
5 | use super::Attribute; |
6 | |
7 | use crate::helpers::ShortSlice; |
8 | use alloc::vec::Vec; |
9 | use core::ops::Deref; |
10 | |
11 | /// A set of [`Attribute`] elements as defined in [`Unicode Extension Attributes`]. |
12 | /// |
13 | /// [`Unicode Extension Attributes`]: https://unicode.org/reports/tr35/tr35.html#u_Extension |
14 | /// |
15 | /// # Examples |
16 | /// |
17 | /// ``` |
18 | /// use icu::locid::extensions::unicode::{Attribute, Attributes}; |
19 | /// |
20 | /// let attribute1: Attribute = |
21 | /// "foobar" .parse().expect("Failed to parse a variant subtag." ); |
22 | /// |
23 | /// let attribute2: Attribute = "testing" |
24 | /// .parse() |
25 | /// .expect("Failed to parse a variant subtag." ); |
26 | /// let mut v = vec![attribute1, attribute2]; |
27 | /// v.sort(); |
28 | /// v.dedup(); |
29 | /// |
30 | /// let attributes: Attributes = Attributes::from_vec_unchecked(v); |
31 | /// assert_eq!(attributes.to_string(), "foobar-testing" ); |
32 | /// ``` |
33 | #[derive (Default, Debug, PartialEq, Eq, Clone, Hash, PartialOrd, Ord)] |
34 | pub struct Attributes(ShortSlice<Attribute>); |
35 | |
36 | impl Attributes { |
37 | /// Returns a new empty set of attributes. Same as [`default()`](Default::default()), but is `const`. |
38 | /// |
39 | /// # Examples |
40 | /// |
41 | /// ``` |
42 | /// use icu::locid::extensions::unicode::Attributes; |
43 | /// |
44 | /// assert_eq!(Attributes::new(), Attributes::default()); |
45 | /// ``` |
46 | #[inline ] |
47 | pub const fn new() -> Self { |
48 | Self(ShortSlice::new()) |
49 | } |
50 | |
51 | /// A constructor which takes a pre-sorted list of [`Attribute`] elements. |
52 | /// |
53 | /// |
54 | /// # Examples |
55 | /// |
56 | /// ``` |
57 | /// use icu::locid::extensions::unicode::{Attribute, Attributes}; |
58 | /// |
59 | /// let attribute1: Attribute = "foobar" .parse().expect("Parsing failed." ); |
60 | /// let attribute2: Attribute = "testing" .parse().expect("Parsing failed." ); |
61 | /// let mut v = vec![attribute1, attribute2]; |
62 | /// v.sort(); |
63 | /// v.dedup(); |
64 | /// |
65 | /// let attributes = Attributes::from_vec_unchecked(v); |
66 | /// ``` |
67 | /// |
68 | /// Notice: For performance- and memory-constrained environments, it is recommended |
69 | /// for the caller to use [`binary_search`](slice::binary_search) instead of [`sort`](slice::sort) |
70 | /// and [`dedup`](Vec::dedup()). |
71 | pub fn from_vec_unchecked(input: Vec<Attribute>) -> Self { |
72 | Self(input.into()) |
73 | } |
74 | |
75 | pub(crate) fn from_short_slice_unchecked(input: ShortSlice<Attribute>) -> Self { |
76 | Self(input) |
77 | } |
78 | |
79 | /// Empties the [`Attributes`] list. |
80 | /// |
81 | /// Returns the old list. |
82 | /// |
83 | /// # Examples |
84 | /// |
85 | /// ``` |
86 | /// use icu::locid::extensions::unicode::{attribute, Attribute, Attributes}; |
87 | /// use writeable::assert_writeable_eq; |
88 | /// |
89 | /// let mut attributes = Attributes::from_vec_unchecked(vec![ |
90 | /// attribute!("foobar" ), |
91 | /// attribute!("testing" ), |
92 | /// ]); |
93 | /// |
94 | /// assert_writeable_eq!(attributes, "foobar-testing" ); |
95 | /// |
96 | /// attributes.clear(); |
97 | /// |
98 | /// assert_writeable_eq!(attributes, "" ); |
99 | /// ``` |
100 | pub fn clear(&mut self) -> Self { |
101 | core::mem::take(self) |
102 | } |
103 | |
104 | pub(crate) fn for_each_subtag_str<E, F>(&self, f: &mut F) -> Result<(), E> |
105 | where |
106 | F: FnMut(&str) -> Result<(), E>, |
107 | { |
108 | self.deref().iter().map(|t| t.as_str()).try_for_each(f) |
109 | } |
110 | } |
111 | |
112 | impl_writeable_for_subtag_list!(Attributes, "foobar" , "testing" ); |
113 | |
114 | impl Deref for Attributes { |
115 | type Target = [Attribute]; |
116 | |
117 | fn deref(&self) -> &[Attribute] { |
118 | self.0.deref() |
119 | } |
120 | } |
121 | |