- From: Boris Zbarsky <bzbarsky@MIT.EDU>
- Date: Tue, 24 Apr 2007 16:53:52 -0500
- To: Steven Pemberton <steven.pemberton@cwi.nl>
- CC: www-style@w3.org
Steven Pemberton wrote: > Are you sure about this? CSS is currently designed so that you can > decide when you are at an element which styles apply, and presumably > implementations use that knowledge. Yes. Furthermore, the style of a node only depends on its ancestors. So when something about a node changes, you only need to recompute style on its descendants. > since the selector ">" and the proposed "<" > are symmetrical, I would expect at worst only a linear increase in > complexity. It would just need a different algorithm. For computing style on a single node, yes. But for deciding what nodes to restyle when something about a node changes, the presence of both "<" and ">" means having to restyle the entire document tree (modulo memory-consuming optimizations). Again, the performance issues with all the "parent" proposals are not in computing style for a single node. They're in handling DOM mutations. Which happen a good bit out there. -Boris
Received on Tuesday, 24 April 2007 21:54:07 UTC