Join Atoms without requiring intermediate Vec

frewsxcv · frewsxcv · commit 9b2ba3d7134b · 2015-07-08T04:42:49.000+09:00
Related to: servo/string-cache#89
diff --git a/components/script/dom/attr.rs b/components/script/dom/attr.rs
@@ -49,7 +49,11 @@ impl AttrValue {
     }
 
     pub fn from_atomic_tokens(atoms: Vec<Atom>) -> AttrValue {
-        let tokens = atoms.iter().map(|x| &**x).collect::<Vec<_>>().connect("\x20");
+        let tokens = atoms.iter().fold(String::new(), |mut s, atom| {
+            if !s.is_empty() { s.push('\x20'); }
+            s.push_str(atom);
+            s
+        });
         AttrValue::TokenList(tokens, atoms)
     }
 

Original file line number	Diff line number	Diff line change
`@@ -49,7 +49,11 @@ impl AttrValue {`
`49`	`49`	`}`
`50`	`50`
`51`	`51`	`pub fn from_atomic_tokens(atoms: Vec<Atom>) -> AttrValue {`
`52`		`- let tokens = atoms.iter().map(\|x\| &**x).collect::<Vec<_>>().connect("\x20");`
	`52`	`+ let tokens = atoms.iter().fold(String::new(), \|mut s, atom\| {`
	`53`	`+ if !s.is_empty() { s.push('\x20'); }`
	`54`	`+ s.push_str(atom);`
	`55`	`+ s`
	`56`	`+ });`
`53`	`57`	`AttrValue::TokenList(tokens, atoms)`
`54`	`58`	`}`
`55`	`59`