Add Atom::to_ascii_lowercase

2 files changed, 37 insertions, 5 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 3b97eec46b6..85265495625 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1629,7 +1629,7 @@ dependencies = [
  "phf 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "phf_codegen 0.7.21 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.24 (registry+https://github.com/rust-lang/crates.io-index)",
- "string_cache 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache_codegen 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "tendril 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -2702,7 +2702,7 @@ dependencies = [
 name = "servo_atoms"
 version = "0.0.1"
 dependencies = [
- "string_cache 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "string_cache 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "string_cache_codegen 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -2851,7 +2851,7 @@ dependencies = [
 
 [[package]]
 name = "string_cache"
-version = "0.5.1"
+version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
  "debug_unreachable 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -3738,7 +3738,7 @@ dependencies = [
 "checksum skeptic 0.9.0 (registry+https://github.com/rust-lang/crates.io-index)" = "dd7d8dc1315094150052d0ab767840376335a98ac66ef313ff911cdf439a5b69"
 "checksum slab 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "17b4fcaed89ab08ef143da37bc52adbcc04d4a69014f4c1208d6b51f0c47bc23"
 "checksum smallvec 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2e40af10aafe98b4d8294ae8388d8a5cd0707c65d364872efe72d063ec44bee0"
-"checksum string_cache 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "2c77392ab481a7b315078ae0cbfd827c7fcd7b0840235f0f9c24d8c7443593b5"
+"checksum string_cache 0.5.2 (registry+https://github.com/rust-lang/crates.io-index)" = "e7c8ba7515dd502b75080d989b819d31fb72686a82320d8006f665003c42ef79"
 "checksum string_cache_codegen 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)" = "479cde50c3539481f33906a387f2bd17c8e87cb848c35b6021d41fb81ff9b4d7"
 "checksum string_cache_shared 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b1884d1bc09741d466d9b14e6d37ac89d6909cbcac41dd9ae982d4d063bbedfc"
 "checksum strsim 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b4d15c810519a91cf877e7e36e63fe068815c678181439f2f29e2562147c3694"
diff --git a/components/style/gecko_string_cache/mod.rs b/components/style/gecko_string_cache/mod.rs
index 79c4ef02138..f9bc9c3a809 100644
--- a/components/style/gecko_string_cache/mod.rs
+++ b/components/style/gecko_string_cache/mod.rs
@@ -11,7 +11,7 @@ use gecko_bindings::bindings::Gecko_Atomize;
 use gecko_bindings::bindings::Gecko_Atomize16;
 use gecko_bindings::bindings::Gecko_ReleaseAtom;
 use gecko_bindings::structs::nsIAtom;
-use nsstring::nsAString;
+use nsstring::{nsAString, nsString};
 use precomputed_hash::PrecomputedHash;
 use std::ascii::AsciiExt;
 use std::borrow::{Cow, Borrow};
@@ -176,6 +176,31 @@ impl WeakAtom {
         let const_ptr: *const nsIAtom = &self.0;
         const_ptr as *mut nsIAtom
     }
+
+    /// Convert this atom to ASCII lower-case
+    pub fn to_ascii_lowercase(&self) -> Atom {
+        let slice = self.as_slice();
+        match slice.iter().position(|&char16| (b'A' as u16) <= char16 && char16 <= (b'Z' as u16)) {
+            None => self.clone(),
+            Some(i) => {
+                let mut buffer: [u16; 64] = unsafe { mem::uninitialized() };
+                let mut vec;
+                let mutable_slice = if let Some(buffer_prefix) = buffer.get_mut(..slice.len()) {
+                    buffer_prefix.copy_from_slice(slice);
+                    buffer_prefix
+                } else {
+                    vec = slice.to_vec();
+                    &mut vec
+                };
+                for char16 in &mut mutable_slice[i..] {
+                    if *char16 <= 0x7F {
+                        *char16 = (*char16 as u8).to_ascii_lowercase() as u16
+                    }
+                }
+                Atom::from(&*mutable_slice)
+            }
+        }
+    }
 }
 
 impl fmt::Debug for WeakAtom {
@@ -321,6 +346,13 @@ impl<'a> From<&'a str> for Atom {
     }
 }
 
+impl<'a> From<&'a [u16]> for Atom {
+    #[inline]
+    fn from(slice: &[u16]) -> Atom {
+        Atom::from(&*nsString::from(slice))
+    }
+}
+
 impl<'a> From<&'a nsAString> for Atom {
     #[inline]
     fn from(string: &nsAString) -> Atom {