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Re: [css3-2d-transforms][css3-images] <position> grammar is duplicated or points to the wrong spec

From: fantasai <fantasai.lists@inkedblade.net>
Date: Tue, 24 Jan 2012 17:30:49 -0800
Message-ID: <4F1F5B49.4020901@inkedblade.net>
To: www-style@w3.org
On 01/24/2012 07:44 AM, Tab Atkins Jr. wrote:
> On Mon, Jan 23, 2012 at 11:33 PM, fantasai
> <fantasai.lists@inkedblade.net>  wrote:
>> On 01/23/2012 11:17 AM, Tab Atkins Jr. wrote:
>>>
>>>
>>> On Mon, Jan 23, 2012 at 9:20 AM, L. David Baron<dbaron@dbaron.org>    wrote:
>>>>
>>>> What's not obtainable using calc()?  Gecko's implementation of
>>>> calc(10% + 5px) for background-position positions the 10% point of
>>>> the image 5px to the left of the 10% point in the container.
>>>
>>>
>>> Note that this is non-conforming with the current calc() spec, as
>>> calc() will simply return a<length>, which is then interpreted as a
>>> simple offset from the side.
>>
>>
>> How is it non-conforming? Where does calc() say it computes to a<length>?
>
> "A math expression has a resolved type, which is one of ‘<length>’,
> ‘<frequency>’, ‘<angle>’, ‘<time>’, or ‘<number>’. [...] If
> percentages are accepted in the context in which the expression is
> placed, a PERCENTAGE token has the type of the value that percentages
> are relative to; otherwise, a math expression containing percentages
> is invalid."

The resolved type is only used to determine the validity of calc().
It has nothing to do with how calc() is turned into a computed value.

~fantasai
Received on Wednesday, 25 January 2012 01:31:18 GMT

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