1 use std::fmt; 2 3 use crate::{capitalize, transform}; 4 5 /// This trait defines a title case conversion. 6 /// 7 /// In Title Case, word boundaries are indicated by spaces, and every word is 8 /// capitalized. 9 /// 10 /// ## Example: 11 /// 12 /// ```rust 13 /// use heck::ToTitleCase; 14 /// 15 /// let sentence = "We have always lived in slums and holes in the wall."; 16 /// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall"); 17 /// ``` 18 pub trait ToTitleCase: ToOwned { 19 /// Convert this type to title case. to_title_case(&self) -> Self::Owned20 fn to_title_case(&self) -> Self::Owned; 21 } 22 23 impl ToTitleCase for str { to_title_case(&self) -> String24 fn to_title_case(&self) -> String { 25 AsTitleCase(self).to_string() 26 } 27 } 28 29 /// This wrapper performs a title case conversion in [`fmt::Display`]. 30 /// 31 /// ## Example: 32 /// 33 /// ``` 34 /// use heck::AsTitleCase; 35 /// 36 /// let sentence = "We have always lived in slums and holes in the wall."; 37 /// assert_eq!(format!("{}", AsTitleCase(sentence)), "We Have Always Lived In Slums And Holes In The Wall"); 38 /// ``` 39 pub struct AsTitleCase<T: AsRef<str>>(pub T); 40 41 impl<T: AsRef<str>> fmt::Display for AsTitleCase<T> { fmt(&self, f: &mut fmt::Formatter) -> fmt::Result42 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { 43 transform(self.0.as_ref(), capitalize, |f| write!(f, " "), f) 44 } 45 } 46 47 #[cfg(test)] 48 mod tests { 49 use super::ToTitleCase; 50 51 macro_rules! t { 52 ($t:ident : $s1:expr => $s2:expr) => { 53 #[test] 54 fn $t() { 55 assert_eq!($s1.to_title_case(), $s2) 56 } 57 }; 58 } 59 60 t!(test1: "CamelCase" => "Camel Case"); 61 t!(test2: "This is Human case." => "This Is Human Case"); 62 t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed Up Camel Case With Some Spaces"); 63 t!(test4: "mixed_up_ snake_case, with some _spaces" => "Mixed Up Snake Case With Some Spaces"); 64 t!(test5: "kebab-case" => "Kebab Case"); 65 t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case"); 66 t!(test7: "snake_case" => "Snake Case"); 67 t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries"); 68 #[cfg(feature = "unicode")] 69 t!(test9: "XΣXΣ baffle" => "Xσxς Baffle"); 70 t!(test10: "XMLHttpRequest" => "Xml Http Request"); 71 } 72