/rust/registry/src/index.crates.io-1949cf8c6b5b557f/writeable-0.5.5/src/cmp.rs
Line | Count | Source |
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 core::cmp::Ordering; |
6 | | use core::fmt; |
7 | | |
8 | | pub(crate) struct WriteComparator<'a> { |
9 | | string: &'a [u8], |
10 | | result: Ordering, |
11 | | } |
12 | | |
13 | | /// This is an infallible impl. Functions always return Ok, not Err. |
14 | | impl<'a> fmt::Write for WriteComparator<'a> { |
15 | | #[inline] |
16 | 0 | fn write_str(&mut self, other: &str) -> fmt::Result { |
17 | 0 | if self.result != Ordering::Equal { |
18 | 0 | return Ok(()); |
19 | 0 | } |
20 | 0 | let cmp_len = core::cmp::min(other.len(), self.string.len()); |
21 | 0 | let (this, remainder) = self.string.split_at(cmp_len); |
22 | 0 | self.string = remainder; |
23 | 0 | self.result = this.cmp(other.as_bytes()); |
24 | 0 | Ok(()) |
25 | 0 | } |
26 | | } |
27 | | |
28 | | impl<'a> WriteComparator<'a> { |
29 | | #[inline] |
30 | 0 | pub fn new(string: &'a (impl AsRef<[u8]> + ?Sized)) -> Self { |
31 | 0 | Self { |
32 | 0 | string: string.as_ref(), |
33 | 0 | result: Ordering::Equal, |
34 | 0 | } |
35 | 0 | } Unexecuted instantiation: <writeable::cmp::WriteComparator>::new::<[u8]> Unexecuted instantiation: <writeable::cmp::WriteComparator>::new::<[u8]> |
36 | | |
37 | | #[inline] |
38 | 0 | pub fn finish(self) -> Ordering { |
39 | 0 | if matches!(self.result, Ordering::Equal) && !self.string.is_empty() { |
40 | | // Self is longer than Other |
41 | 0 | Ordering::Greater |
42 | | } else { |
43 | 0 | self.result |
44 | | } |
45 | 0 | } |
46 | | } |
47 | | |
48 | | #[cfg(test)] |
49 | | mod tests { |
50 | | use super::*; |
51 | | use core::fmt::Write; |
52 | | |
53 | | mod data { |
54 | | include!("../tests/data/data.rs"); |
55 | | } |
56 | | |
57 | | #[test] |
58 | | fn test_write_char() { |
59 | | for a in data::KEBAB_CASE_STRINGS { |
60 | | for b in data::KEBAB_CASE_STRINGS { |
61 | | let mut wc = WriteComparator::new(a); |
62 | | for ch in b.chars() { |
63 | | wc.write_char(ch).unwrap(); |
64 | | } |
65 | | assert_eq!(a.cmp(b), wc.finish(), "{a} <=> {b}"); |
66 | | } |
67 | | } |
68 | | } |
69 | | |
70 | | #[test] |
71 | | fn test_write_str() { |
72 | | for a in data::KEBAB_CASE_STRINGS { |
73 | | for b in data::KEBAB_CASE_STRINGS { |
74 | | let mut wc = WriteComparator::new(a); |
75 | | wc.write_str(b).unwrap(); |
76 | | assert_eq!(a.cmp(b), wc.finish(), "{a} <=> {b}"); |
77 | | } |
78 | | } |
79 | | } |
80 | | |
81 | | #[test] |
82 | | fn test_mixed() { |
83 | | for a in data::KEBAB_CASE_STRINGS { |
84 | | for b in data::KEBAB_CASE_STRINGS { |
85 | | let mut wc = WriteComparator::new(a); |
86 | | let mut first = true; |
87 | | for substr in b.split('-') { |
88 | | if first { |
89 | | first = false; |
90 | | } else { |
91 | | wc.write_char('-').unwrap(); |
92 | | } |
93 | | wc.write_str(substr).unwrap(); |
94 | | } |
95 | | assert_eq!(a.cmp(b), wc.finish(), "{a} <=> {b}"); |
96 | | } |
97 | | } |
98 | | } |
99 | | } |