Re: [css-counter-styles] position keywords in list-style

On Thu, Apr 3, 2014 at 12:21 PM, Xidorn Quan <quanxunzhen@gmail.com> wrote:

>
> On Thu, Apr 3, 2014 at 12:01 PM, Tab Atkins Jr. <jackalmage@gmail.com>wrote:
>
>>
>> On the other hand, in the call today dbaron pointed out that
>> animation/transition/list-style all have ambiguity issues that they
>> solve by just trying as hard as they can to parse - you're allowed to
>> name an animation "backwards", for instance.
>>
>
> I see what dbaron said. However, I don't think it is a good idea. Although
> it is easy to implement, it is dangerous for forward compatibility. For
> example, if someone defines a keyframes called 'move', and uses it in
> shorthand animation property like 'animation: move ease 1s', and we later
> defines a new timing-function called 'move' as well, the meaning of the
> value will be changed.
>
> IMO, If we decide to allow trying to parse as hard as possible, name must
> be parsed in the highest priority, and then moved to other slot if possible
> or necessary.
>

Things could be even more complex for list-style. As animation is still in
WD, though very dangerous, it is possible for us to announce that the first
none or identifier-like value will always be parsed into animation-name
instead of any keywords. But for list-style, we cannot do this, as it
already accepts position keywords to be the first part. That is to say, if
any new position keyword is defined, meaning of value of list-style may be
affected.

- Xidorn