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Re: Parent Combinator / Parent pseudo-class

From: Brad Kemper <brkemper@comcast.net>
Date: Wed, 23 Jul 2008 10:58:58 -0700
Message-Id: <F64220CC-C08C-4FD6-B527-6F117F5C4CF4@comcast.net>
To: Boris Zbarsky <bzbarsky@MIT.EDU>
Cc: www-style list <www-style@w3.org>

On Jul 23, 2008, at 10:43 AM, Boris Zbarsky <bzbarsky@MIT.EDU> wrote:

> Brad Kemper wrote:
>> In fact, I do have an example of that, and it does not seem slow at  
>> all
>
> "slow" is a relative concept.  Handling DOM mutations in this  
> document is slower than if the '+' combinator were not used.  It's  
> still fast compared to human reaction times.
>
> Of course your page is two orders of magnitude smaller than typical  
> "commercial" webpages, and about 4 orders of magnitude smaller than  
> typical "big" webpages where algorithmic complexity issues _really_  
> start to kick in.
>
> Seriously, users want arbitrarily sized HTML documents handled in a  
> "non-laggy" way.  In practice that means that nothing should ever  
> take longer than 200ms, and continuous updates need to happen every  
> 20ms or more often.  If it takes you longer than 20ms to respond to  
> arbitrary DOM changes for an arbitrary HTML document, you will be  
> perceived as "slow".
>
> -Boris

And yet implementors impletent adjacency selectors but not ":has- 
child", even though the issues seem to the same. 
Received on Wednesday, 23 July 2008 17:59:59 GMT

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