Re: Parent Combinator / Parent pseudo-class

Tab Atkins Jr. wrote:
> Stephen's original suggestion may require that, yes (though I doubt it 
> in an intelligent implementation).  But the :matches pseudoclass does 
> *not* require this at all.  You would hold a reference to the main 
> element and then walk down in the ordinary matching pattern.

This is talking about the easy problem: matching the selector to nodes. 
  That part is indeed.... easy.

The hard problem is deciding which parts of the DOM tree need to have 
style reresolution done when a DOM mutation happens.

> As Brad says, authors will always find a way around.  This particular 
> thing can be done by walking the DOM in javascript and directly playing 
> with styles.

Except for the part about DOM mutations... of course that can be done 
too, but it'll be hideously slow.

> The use-cases have already been noted, and are relatively significant 

I don't think anyone is debating it.  What UA implementors are saying is 
that they haven't thought of a good way to implement it yet without 
crippling performance of DOM mutation, and they aren't willing to 
cripple that.

-Boris

Received on Wednesday, 23 July 2008 16:22:47 UTC