smart_format/case/
capitalize.rs

1use crate::prelude::*;
2
3pub struct Capitalize<T: fmt::Display>(pub T);
4
5impl<T: fmt::Display> fmt::Display for Capitalize<T> {
6    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
7        use fmt::Write;
8
9        let mut first = true;
10
11        self.0.format_with(move |s: Option<&str>| {
12            let Some(s) = s else { return Ok(()) };
13            let mut i = s.chars();
14
15            if first {
16                for c in i.next().into_iter().flat_map(char::to_uppercase) {
17                    first = false;
18                    f.write_char(c)?;
19                }
20            }
21
22            for c in i.flat_map(char::to_lowercase) {
23                f.write_char(c)?;
24            }
25
26            Ok(())
27        })?;
28
29        Ok(())
30    }
31}
32
33#[cfg(test)]
34mod tests {
35    use super::super::tests::WORD_CASES;
36    use super::*;
37
38    #[test]
39    fn it_works() {
40        fn test_case(expected: &str, sample: &str) {
41            assert_eq!(expected, Capitalize(sample).to_string());
42        }
43
44        for &word in WORD_CASES {
45            test_case("Word", word);
46        }
47    }
48
49    #[test]
50    fn is_works_with_dyn_display() {
51        fn test_case(expected: &str, sample: &dyn fmt::Display) {
52            assert_eq!(expected, Capitalize(sample).to_string());
53        }
54
55        for &word in WORD_CASES {
56            test_case("Word", &word);
57        }
58    }
59}
smart_format/case/capitalize.rs

smart_format/case/
capitalize.rs
