auto merge of #4353 : brunoabinader/servo/domtokenlist, r=Ms2ger

Specs:
https://dom.spec.whatwg.org/#dom-domtokenlist-add
https://dom.spec.whatwg.org/#dom-domtokenlist-remove
https://dom.spec.whatwg.org/#dom-domtokenlist-toggle
https://dom.spec.whatwg.org/#concept-dtl-update
https://dom.spec.whatwg.org/#concept-ordered-set-serializer

Closes #3138.

1 files changed, 15 insertions, 3 deletions

diff --git a/components/script/dom/attr.rs b/components/script/dom/attr.rs
index d1b288bd7ad..014fa5f5357 100644
--- a/components/script/dom/attr.rs
+++ b/components/script/dom/attr.rs
@@ -37,9 +37,21 @@ pub enum AttrValue {
 }
 
 impl AttrValue {
-    pub fn from_tokenlist(tokens: DOMString) -> AttrValue {
-        let atoms = split_html_space_chars(tokens.as_slice())
-            .map(|token| Atom::from_slice(token)).collect();
+    pub fn from_serialized_tokenlist(tokens: DOMString) -> AttrValue {
+        let mut atoms: Vec<Atom> = vec!();
+        for token in split_html_space_chars(tokens.as_slice()).map(|slice| Atom::from_slice(slice)) {
+            if !atoms.iter().any(|atom| *atom == token) {
+                atoms.push(token);
+            }
+        }
+        AttrValue::TokenList(tokens, atoms)
+    }
+
+    pub fn from_atomic_tokens(atoms: Vec<Atom>) -> AttrValue {
+        let tokens = {
+            let slices: Vec<&str> = atoms.iter().map(|atom| atom.as_slice()).collect();
+            slices.connect("\x20")
+        };
         AttrValue::TokenList(tokens, atoms)
     }