Implement Ord and PartialOrd for UniCase<AsRef<str>>

src/lib.rs

@@ -17,6 +17,7 @@
 //! ```
 
 use std::ascii::AsciiExt;
+use std::cmp::Ordering;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::ops::{Deref, DerefMut};
@@ -41,6 +42,20 @@ impl<S> DerefMut for UniCase<S> {
     }
 }
 
+impl<T: AsRef<str>> PartialOrd for UniCase<T> {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+impl<T: AsRef<str>> Ord for UniCase<T> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        let self_chars = self.as_ref().chars().map(|c| c.to_ascii_uppercase());
+        let other_chars = other.as_ref().chars().map(|c| c.to_ascii_uppercase());
+        self_chars.cmp(other_chars)
+    }
+}
+
 impl<S: AsRef<str>> AsRef<str> for UniCase<S> {
     #[inline]
     fn as_ref(&self) -> &str {
@@ -108,4 +123,16 @@ mod test {
         assert_eq!(a, b);
         assert_eq!(hash(&a), hash(&b));
     }
+
+    #[test]
+    fn test_case_cmp() {
+        assert!(UniCase("foobar") == UniCase("FOOBAR"));
+        assert!(UniCase("a") < UniCase("B"));
+
+        assert!(UniCase("A") < UniCase("b"));
+        assert!(UniCase("aa") > UniCase("a"));
+
+        assert!(UniCase("a") < UniCase("aa"));
+        assert!(UniCase("a") < UniCase("AA"));
+    }
 }