Re: [css3-conditional] Resolving issues

On Wed, Sep 26, 2012 at 12:05 AM, Simon Sapin <simon.sapin@kozea.fr> wrote:
> Le 26/09/2012 01:08, Tab Atkins Jr. a écrit :
>> We'd probably also want negations of unknown functions to
>> evaluate as false.  Basically, only an "or" should be able to
>> whitewash away the unrecognized-ness.
>
> Maybe, but why? In terms of boolean logic, having "A" and "not A" both
> evaluate to false is very strange to me. Is there a use case I’m missing?

I agree that it's strange, but you simply *don't know* whether it
should be true or not.  My suggested solution is kinda similar to
NaN-poisoning, where once a NaN is introduced, it remains NaN until
you do something special with it.  This just wipes out the entire
unknown clause.

~TJ

Received on Wednesday, 26 September 2012 17:34:01 UTC