2 files changed, 21 insertions, 0 deletions
diff --git a/components/util/lib.rs b/components/util/lib.rs
index 46e8b0b60df..3f4146eedfe 100644
--- a/components/util/lib.rs
+++ b/components/util/lib.rs
@@ -26,6 +26,7 @@ extern crate sync;
 extern crate task_info;
 extern crate "time" as std_time;
 extern crate string_cache;
+extern crate unicode;
 extern crate url;
 
 #[phase(plugin)]
diff --git a/components/util/str.rs b/components/util/str.rs
index 6e88f0ba4f8..f08ae1178d9 100644
--- a/components/util/str.rs
+++ b/components/util/str.rs
@@ -7,6 +7,7 @@ use geometry::Au;
 use std::from_str::FromStr;
 use std::iter::Filter;
 use std::str::{CharEq, CharSplits};
+use unicode::char::to_lowercase;
 
 pub type DOMString = String;
 pub type StaticCharVec = &'static [char];
@@ -184,3 +185,22 @@ pub fn parse_length(mut value: &str) -> LengthOrPercentageOrAuto {
 }
 
 
+#[deriving(Clone, Eq, PartialEq, Hash, Show)]
+pub struct LowercaseString {
+    inner: String,
+}
+
+impl LowercaseString {
+    pub fn new(s: &str) -> LowercaseString {
+        LowercaseString {
+            inner: s.chars().map(to_lowercase).collect(),
+        }
+    }
+}
+
+impl Str for LowercaseString {
+    #[inline]
+    fn as_slice(&self) -> &str {
+        self.inner.as_slice()
+    }
+}