- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Fri, 25 May 2012 10:57:37 -0400
- To: www-style@w3.org
On 5/25/12 10:25 AM, Marat Tanalin | tanalin.com wrote: > BTW, browser vendors (WebKit [2], Mozilla [3]) already take steps to make selectors much faster and, in most cases, independent from how long selector is. There's no free lunch. The optimizations you link to have a nontrivial memory cost, and worse yet make it much harder to perform selector matching in a parallelizable manner (because it becomes stateful). UAs are sort of forced to do them because sites are using descendant combinators willy nilly (not least because CSS preprocessors output them all over the place)... Long selector chains can still cause performance issues when trying to handle dynamic changes, by the way, where the optimizations you link to don't apply right now. -Boris
Received on Friday, 25 May 2012 15:00:38 UTC