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Re: [mediaqueries] @media not (unsupported-media-feature) v.s. @media not (unsupported + syntax)

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Thu, 26 Mar 2015 09:12:35 -0700
Message-ID: <CAAWBYDCesViv+r798KRramcMzvH1e98gZOGUi29f0mjT52dw2g@mail.gmail.com>
To: Simon Sapin <simon.sapin@exyr.org>
Cc: www-style list <www-style@w3.org>
On Thu, Mar 26, 2015 at 8:54 AM, Simon Sapin <simon.sapin@exyr.org> wrote:
> MQ4 adds a <general-enclosed> term to its grammar that accepts almost
> anything and evaluates to false. This is to support future extensions.
>
> This means that a query like `not (unsupported + syntax)` evaluates to true.
>
> However, something like `not (unsupported-media-feature)` with the normal
> <media-feature> syntax evaluates to false:
>
>> An unknown <mf-name> or <mf-value>, or disallowed <mf-value>, must
>> make the entire <media-query> be replaced by not all.
>
>
>
> This is inconsistent. Should one of these two cases be changed to match the
> other?

I seem to recall us discussing this back when we added
<general-enclosed>.  I don't remember the conclusion, but I think my
argument was that the "just negate the whole danged thing" behavior
was *identical* to "just negate the one unrecognized thing" (because
you could only use AND to combine) *except for* the case that the
whole thing was negated.  I'd need to go look up the old thread on it.

~TJ
Received on Thursday, 26 March 2015 16:13:32 UTC

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