1 files changed, 71 insertions, 0 deletions
diff --git a/third_party/rust/heck/src/title.rs b/third_party/rust/heck/src/title.rs
new file mode 100644
index 0000000000..fdf175b733
--- /dev/null
+++ b/third_party/rust/heck/src/title.rs
@@ -0,0 +1,71 @@
+use std::fmt;
+
+use crate::{capitalize, transform};
+
+/// This trait defines a title case conversion.
+///
+/// In Title Case, word boundaries are indicated by spaces, and every word is
+/// capitalized.
+///
+/// ## Example:
+///
+/// ```rust
+/// use heck::ToTitleCase;
+///
+/// let sentence = "We have always lived in slums and holes in the wall.";
+/// assert_eq!(sentence.to_title_case(), "We Have Always Lived In Slums And Holes In The Wall");
+/// ```
+pub trait ToTitleCase: ToOwned {
+    /// Convert this type to title case.
+    fn to_title_case(&self) -> Self::Owned;
+}
+
+impl ToTitleCase for str {
+    fn to_title_case(&self) -> String {
+        AsTitleCase(self).to_string()
+    }
+}
+
+/// This wrapper performs a title case conversion in [`fmt::Display`].
+///
+/// ## Example:
+///
+/// ```
+/// use heck::AsTitleCase;
+///
+/// let sentence = "We have always lived in slums and holes in the wall.";
+/// assert_eq!(format!("{}", AsTitleCase(sentence)), "We Have Always Lived In Slums And Holes In The Wall");
+/// ```
+pub struct AsTitleCase<T: AsRef<str>>(pub T);
+
+impl<T: AsRef<str>> fmt::Display for AsTitleCase<T> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        transform(self.0.as_ref(), capitalize, |f| write!(f, " "), f)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::ToTitleCase;
+
+    macro_rules! t {
+        ($t:ident : $s1:expr => $s2:expr) => {
+            #[test]
+            fn $t() {
+                assert_eq!($s1.to_title_case(), $s2)
+            }
+        };
+    }
+
+    t!(test1: "CamelCase" => "Camel Case");
+    t!(test2: "This is Human case." => "This Is Human Case");
+    t!(test3: "MixedUP CamelCase, with some Spaces" => "Mixed Up Camel Case With Some Spaces");
+    t!(test4: "mixed_up_ snake_case, with some _spaces" => "Mixed Up Snake Case With Some Spaces");
+    t!(test5: "kebab-case" => "Kebab Case");
+    t!(test6: "SHOUTY_SNAKE_CASE" => "Shouty Snake Case");
+    t!(test7: "snake_case" => "Snake Case");
+    t!(test8: "this-contains_ ALLKinds OfWord_Boundaries" => "This Contains All Kinds Of Word Boundaries");
+    #[cfg(feature = "unicode")]
+    t!(test9: "XΣXΣ baﬄe" => "Xσxς Baﬄe");
+    t!(test10: "XMLHttpRequest" => "Xml Http Request");
+}