1 use core::fmt; 2 3 use alloc::{ 4 borrow::ToOwned, 5 string::{String, ToString}, 6 }; 7 8 use crate::{capitalize, transform}; 9 10 /// This trait defines a title case conversion. 11 /// 12 /// In Title Case, word boundaries are indicated by spaces, and every word is 13 /// capitalized. 14 /// 15 /// ## Example: 16 /// 17 /// ```rust 18 /// use heck::ToTitleCase; 19 /// 20 /// let sentence = "We have always lived in slums and holes in the wall."; 21 /// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall"); 22 /// ``` 23 pub trait ToTitleCase: ToOwned { 24 /// Convert this type to title case. to_title_case(&self) -> Self::Owned25 fn to_title_case(&self) -> Self::Owned; 26 } 27 28 impl ToTitleCase for str { to_title_case(&self) -> String29 fn to_title_case(&self) -> String { 30 AsTitleCase(self).to_string() 31 } 32 } 33 34 /// This wrapper performs a title case conversion in [`fmt::Display`]. 35 /// 36 /// ## Example: 37 /// 38 /// ``` 39 /// use heck::AsTitleCase; 40 /// 41 /// let sentence = "We have always lived in slums and holes in the wall."; 42 /// assert_eq!(format!("{}", AsTitleCase(sentence)), "We Have Always Lived In Slums And Holes In The Wall"); 43 /// ``` 44 pub struct AsTitleCase<T: AsRef<str>>(pub T); 45 46 impl<T: AsRef<str>> fmt::Display for AsTitleCase<T> { fmt(&self, f: &mut fmt::Formatter) -> fmt::Result47 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 48 transform(self.0.as_ref(), capitalize, |f| write!(f, " "), f) 49 } 50 } 51 52 #[cfg(test)] 53 mod tests { 54 use super::ToTitleCase; 55 56 macro_rules! t { 57 ($t:ident : $s1:expr => $s2:expr) => { 58 #[test] 59 fn $t() { 60 assert_eq!($s1.to_title_case(), $s2) 61 } 62 }; 63 } 64 65 t!(test1: "CamelCase" => "Camel Case"); 66 t!(test2: "This is Human case." => "This Is Human Case"); 67 t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed Up Camel Case With Some Spaces"); 68 t!(test4: "mixed_up_ snake_case, with some _spaces" => "Mixed Up Snake Case With Some Spaces"); 69 t!(test5: "kebab-case" => "Kebab Case"); 70 t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case"); 71 t!(test7: "snake_case" => "Snake Case"); 72 t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries"); 73 t!(test9: "XΣXΣ baffle" => "Xσxς Baffle"); 74 t!(test10: "XMLHttpRequest" => "Xml Http Request"); 75 } 76