heck/
upper_camel.rs

1use core::fmt;
2
3use alloc::{
4    borrow::ToOwned,
5    string::{String, ToString},
6};
7
8use crate::{capitalize, transform};
9
10/// This trait defines an upper camel case conversion.
11///
12/// In UpperCamelCase, word boundaries are indicated by capital letters,
13/// including the first word.
14///
15/// ## Example:
16///
17/// ```rust
18/// use heck::ToUpperCamelCase;
19///
20/// let sentence = "We are not in the least afraid of ruins.";
21/// assert_eq!(sentence.to_upper_camel_case(), "WeAreNotInTheLeastAfraidOfRuins");
22/// ```
23pub trait ToUpperCamelCase: ToOwned {
24    /// Convert this type to upper camel case.
25    fn to_upper_camel_case(&self) -> Self::Owned;
26}
27
28impl ToUpperCamelCase for str {
29    fn to_upper_camel_case(&self) -> String {
30        AsUpperCamelCase(self).to_string()
31    }
32}
33
34/// `ToPascalCase` is an alias for [`ToUpperCamelCase`]. See ToUpperCamelCase for more
35/// documentation.
36pub trait ToPascalCase: ToOwned {
37    /// Convert this type to upper camel case.
38    fn to_pascal_case(&self) -> Self::Owned;
39}
40
41impl<T: ?Sized + ToUpperCamelCase> ToPascalCase for T {
42    fn to_pascal_case(&self) -> Self::Owned {
43        self.to_upper_camel_case()
44    }
45}
46
47/// This wrapper performs a upper camel case conversion in [`fmt::Display`].
48///
49/// ## Example:
50///
51/// ```
52/// use heck::AsUpperCamelCase;
53///
54/// let sentence = "We are not in the least afraid of ruins.";
55/// assert_eq!(format!("{}", AsUpperCamelCase(sentence)), "WeAreNotInTheLeastAfraidOfRuins");
56/// ```
57pub struct AsUpperCamelCase<T: AsRef<str>>(pub T);
58
59impl<T: AsRef<str>> fmt::Display for AsUpperCamelCase<T> {
60    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
61        transform(self.0.as_ref(), capitalize, |_| Ok(()), f)
62    }
63}
64
65#[cfg(test)]
66mod tests {
67    use super::ToUpperCamelCase;
68
69    macro_rules! t {
70        ($t:ident : $s1:expr => $s2:expr) => {
71            #[test]
72            fn $t() {
73                assert_eq!($s1.to_upper_camel_case(), $s2)
74            }
75        };
76    }
77
78    t!(test1: "CamelCase" => "CamelCase");
79    t!(test2: "This is Human case." => "ThisIsHumanCase");
80    t!(test3: "MixedUP_CamelCase, with some Spaces" => "MixedUpCamelCaseWithSomeSpaces");
81    t!(test4: "mixed_up_ snake_case, with some _spaces" => "MixedUpSnakeCaseWithSomeSpaces");
82    t!(test5: "kebab-case" => "KebabCase");
83    t!(test6: "SHOUTY_SNAKE_CASE" => "ShoutySnakeCase");
84    t!(test7: "snake_case" => "SnakeCase");
85    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "ThisContainsAllKindsOfWordBoundaries");
86    t!(test9: "XΣXΣ baffle" => "XσxςBaffle");
87    t!(test10: "XMLHttpRequest" => "XmlHttpRequest");
88}