Re: [css-counter-styles] Behavior of zero in system 'alphabetic' & 'symbolic'

On 24/02/2014 21:49, Tab Atkins Jr. wrote:
> On Sun, Feb 23, 2014 at 12:12 AM, Xidorn Quan <quanxunzhen@gmail.com> wrote:
>> Hi,
>>
>> The spec says, 'alphabetic' and 'symbolic' are "defined only over
>> strictly positive counter values", while they are also
>> negative-capable. Consequently, if an author defines a style:
>>
>> @counter-style a { system: symbolic; range: -10 10; symbols: a; }
>>
>> and use value -2 - 2, then, according to the rules, he will get: -aa,
>> -a, 0, a, aa. The zero in the middle seems to be strange. I propose
>> that we could make the defination cover zero, and generate an empty
>> sequence for zero.
>
> I agree that the 0 in the middle is strange, but I think it's even
> stranger to generate an empty counter representation.  Note that I'd
> also have to then hook into the rest of the algorithm, so that it
> doesn't get a prefix, suffix, or pad added to it.

How common is it to have all of negative, zero, and positive counter 
values in the same list?

As far as I can tell, it’s uncommon enough (less than negative counter 
values in general, which are not common themselves) that we shouldn’t 
bother making it pretty. (This is a feeling based on zero data, though.)

-- 
Simon Sapin