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Re: css3-background: grammar issue

From: fantasai <fantasai.lists@inkedblade.net>
Date: Mon, 22 Feb 2010 16:23:41 -0800
Message-ID: <4B83200D.8020907@inkedblade.net>
To: Yves Lafon <ylafon@w3.org>
CC: Bert Bos <bert@w3.org>, www-style@w3.org
On 02/17/2010 07:46 AM, Yves Lafon wrote:
> On Wed, 17 Feb 2010, Bert Bos wrote:
>
>> On Saturday 09 January 2010 09:11:53 Yves Lafon wrote:
>
>>> There are two possible paths for solving this:
>>> 1/ disallowing bckground to tart with a <bg-size> (there is already a
>>> rule forbidding <bg-position> after a <bg-size>, so it's in the same
>>> range).
>>
>> There is no reason to disallow it on syntactical grounds, but one could
>> argue that it looks confusing. However, I don't think it is a very
>> strong argument.
>
> Ok, so why is CSS3-background disallowing
> background: url("foo.png") / 10em black 10em
> and not
> background: url("foo.png") 10em black / 10em
>
> There is nothing confusing in those two cases, and the generalisation of
> the simple rule "/ <bg-size> immediately followed by <bg-position>" into
> "<bg-position> must not occur before '/ <bg-size>" seems like a strange
> decision as well. Just saying that 'background' can't start with
> '/ <bg-size>' is in the same range of text-based constraint.

Hello Yves,
Based on your comments on the background shorthand syntax and the discussion
in the CSSWG's last telecon
   <http://lists.w3.org/Archives/Public/www-style/2010Feb/0163.html>

I propose the following changes:

   - Change the token '/' to the keyword 'as'
   - Replace
       # where ‘<bg-position>’ must occur before ‘/ <bg-size>’ if both are present.
     with
       | where '<bg-position>' must not occur immediately after 'as <bg-size>'

Would this address your concerns?

~fantasai
Received on Tuesday, 23 February 2010 00:24:21 GMT

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