Re: [css-syntax] Removed <unicode-range-token>, please review

On Thu, Nov 13, 2014 at 7:42 PM, John Daggett <jdaggett@mozilla.com> wrote:
> Tab Atkins wrote:
>> Per the resolution from the 2014-07-02 telcon, I've removed the
>> <unicode-range-token> from Syntax entirely, and replaced it with a
>> <urange> microsyntax: <http://dev.w3.org/csswg/css-syntax/#urange>
>>
>> If you're interested in this kind of thing, please give it a look-over
>> and verify that I haven't missed any cases or made any mistakes.  It
>> was simpler than I thought it would be to spec out.
>
> Tab, this doesn't seem like a good change. The underlying problem is
> in the *tokenization* aspect of UNICODE-RANGE. If you eliminate the
> token, I'm not sure I see the reason to try and describe the syntax
> within the Syntax spec when it's used in only one place, namely the
> definition of the 'unicode-range' descriptor.

It has to be described somewhere, and as a "weird syntax" like An+B
that involves reinterpreting tokens into a completely different
meaning, it seemed appropriate to put it into here.

If you'd rather have it in Fonts, that's fine.  It just needed to be written.

>> In section 7.1:
>>
>> To determine what codepoints the <urange> represents:
>>
>> 1. If end value is greater than the maximum allowed code point, set
>>    it to the maximum allowed code point.
>
> No, this is invalid syntax and the descriptor defintion should be rejected.
>
>> 2. If start value is greater than end value, the <urange>
>>    represents an empty range of codepoints.
>
> Ditto. Plus you introduce serialization problems by allowing "empty
> range". I went through this with the Fonts spec, that's why it isn't
> defined this way. :)

Sure, I can just make those both invalid <urange> rather than empty or
truncated.  Not a problem.

~TJ

Received on Friday, 14 November 2014 05:03:58 UTC