1 files changed, 20 insertions, 0 deletions
diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index b612c027c45..63ba6d7977c 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -13,6 +13,7 @@ use gecko_bindings::bindings::Gecko_ReleaseAtom;
 use gecko_bindings::structs::nsIAtom;
 use nsstring::nsAString;
 use precomputed_hash::PrecomputedHash;
+use std::ascii::AsciiExt;
 use std::borrow::{Cow, Borrow};
 use std::char::{self, DecodeUtf16};
 use std::fmt::{self, Write};
@@ -224,6 +225,25 @@ impl Atom {
             Atom(WeakAtom::new(ptr))
         }
     }
+
+    /// Return whether two atoms are ASCII-case-insensitive matches
+    pub fn eq_ignore_ascii_case(&self, other: &Self) -> bool {
+        let a = self.as_slice();
+        let b = other.as_slice();
+        a.len() == b.len() && a.iter().zip(b).all(|(&a16, &b16)| {
+            if a16 <= 0x7F && b16 <= 0x7F {
+                (a16 as u8).eq_ignore_ascii_case(&(b16 as u8))
+            } else {
+                a16 == b16
+            }
+        })
+    }
+
+    /// Return whether this atom is an ASCII-case-insensitive match for the given string
+    pub fn eq_str_ignore_ascii_case(&self, other: &str) -> bool {
+        self.chars().map(|r| r.map(|c: char| c.to_ascii_lowercase()))
+        .eq(other.chars().map(|c: char| Ok(c.to_ascii_lowercase())))
+    }
 }
 
 impl Hash for Atom {