1use core::fmt;
2
3use alloc::{borrow::ToOwned, string::ToString};
4
5use crate::{transform, uppercase};
6
7/// This trait defines a shouty snake case conversion.
8///
9/// In SHOUTY_SNAKE_CASE, word boundaries are indicated by underscores and all
10/// words are in uppercase.
11///
12/// ## Example:
13///
14/// ```rust
15/// use heck::ToShoutySnakeCase;
16///
17/// let sentence = "That world is growing in this minute.";
18/// assert_eq!(sentence.to_shouty_snake_case(), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
19/// ```
20pub trait ToShoutySnakeCase: ToOwned {
21 /// Convert this type to shouty snake case.
22 fn to_shouty_snake_case(&self) -> Self::Owned;
23}
24
25/// Oh heck, `ToShoutySnekCase` is an alias for [`ToShoutySnakeCase`]. See
26/// ToShoutySnakeCase for more documentation.
27pub trait ToShoutySnekCase: ToOwned {
28 /// CONVERT THIS TYPE TO SNEK CASE.
29 #[allow(non_snake_case)]
30 fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned;
31}
32
33impl<T: ?Sized + ToShoutySnakeCase> ToShoutySnekCase for T {
34 fn TO_SHOUTY_SNEK_CASE(&self) -> Self::Owned {
35 self.to_shouty_snake_case()
36 }
37}
38
39impl ToShoutySnakeCase for str {
40 fn to_shouty_snake_case(&self) -> Self::Owned {
41 AsShoutySnakeCase(self).to_string()
42 }
43}
44
45/// This wrapper performs a shouty snake case conversion in [`fmt::Display`].
46///
47/// ## Example:
48///
49/// ```
50/// use heck::AsShoutySnakeCase;
51///
52/// let sentence = "That world is growing in this minute.";
53/// assert_eq!(format!("{}", AsShoutySnakeCase(sentence)), "THAT_WORLD_IS_GROWING_IN_THIS_MINUTE");
54/// ```
55pub struct AsShoutySnakeCase<T: AsRef<str>>(pub T);
56
57impl<T: AsRef<str>> fmt::Display for AsShoutySnakeCase<T> {
58 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
59 transform(self.0.as_ref(), with_word:uppercase, |f: &mut Formatter<'_>| write!(f, "_"), f)
60 }
61}
62
63#[cfg(test)]
64mod tests {
65 use super::ToShoutySnakeCase;
66
67 macro_rules! t {
68 ($t:ident : $s1:expr => $s2:expr) => {
69 #[test]
70 fn $t() {
71 assert_eq!($s1.to_shouty_snake_case(), $s2)
72 }
73 };
74 }
75
76 t!(test1: "CamelCase" => "CAMEL_CASE");
77 t!(test2: "This is Human case." => "THIS_IS_HUMAN_CASE");
78 t!(test3: "MixedUP CamelCase, with some Spaces" => "MIXED_UP_CAMEL_CASE_WITH_SOME_SPACES");
79 t!(test4: "mixed_up_snake_case with some _spaces" => "MIXED_UP_SNAKE_CASE_WITH_SOME_SPACES");
80 t!(test5: "kebab-case" => "KEBAB_CASE");
81 t!(test6: "SHOUTY_SNAKE_CASE" => "SHOUTY_SNAKE_CASE");
82 t!(test7: "snake_case" => "SNAKE_CASE");
83 t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "THIS_CONTAINS_ALL_KINDS_OF_WORD_BOUNDARIES");
84 t!(test9: "XΣXΣ baffle" => "XΣXΣ_BAFFLE");
85 t!(test10: "XMLHttpRequest" => "XML_HTTP_REQUEST");
86}
87