nu_utils/
casing.rs

1use std::cmp::Ordering;
2use unicase::UniCase;
3
4pub trait IgnoreCaseExt {
5    /// Returns a [case folded] equivalent of this string, as a new String.
6    ///
7    /// Case folding is primarily based on lowercase mapping, but includes
8    /// additional changes to the source text to help make case folding
9    /// language-invariant and consistent. Case folded text should be used
10    /// solely for processing and generally should not be stored or displayed.
11    ///
12    /// [case folded]: <https://unicode.org/faq/casemap_charprop.html#2>
13    fn to_folded_case(&self) -> String;
14
15    /// Checks that two strings are a case-insensitive match.
16    ///
17    /// Essentially `to_folded_case(a) == to_folded_case(b)`, but without
18    /// allocating and copying string temporaries. Because case folding involves
19    /// Unicode table lookups, it can sometimes be more efficient to use
20    /// `to_folded_case` to case fold once and then compare those strings.
21    fn eq_ignore_case(&self, other: &str) -> bool;
22
23    /// Compares two strings case-insensitively.
24    ///
25    /// Essentially `to_folded_case(a) == to_folded_case(b)`, but without
26    /// allocating and copying string temporaries. Because case folding involves
27    /// Unicode table lookups, it can sometimes be more efficient to use
28    /// `to_folded_case` to case fold once and then compare those strings.
29    ///
30    /// Note that this *only* ignores case, comparing the folded strings without
31    /// any other collation data or locale, so the sort order may be surprising
32    /// outside of ASCII characters.
33    fn cmp_ignore_case(&self, other: &str) -> Ordering;
34}
35
36impl IgnoreCaseExt for str {
37    fn to_folded_case(&self) -> String {
38        UniCase::new(self).to_folded_case()
39    }
40
41    fn eq_ignore_case(&self, other: &str) -> bool {
42        UniCase::new(self) == UniCase::new(other)
43    }
44
45    fn cmp_ignore_case(&self, other: &str) -> Ordering {
46        UniCase::new(self).cmp(&UniCase::new(other))
47    }
48}
nu_utils/casing.rs

nu_utils/
casing.rs
