- From: Phillips, Addison <addison@lab126.com>
- Date: Tue, 17 Sep 2013 04:41:42 +0000
- To: John Daggett <jdaggett@mozilla.com>, Anne van Kesteren <annevk@annevk.nl>
- CC: Richard Ishida <ishida@w3.org>, W3C Style <www-style@w3.org>, "www International" <www-international@w3.org>
I tend to agree: this is an existing syntax. I don't seen any issues with the accuracy of the existing text. One might have argued with the syntax back in v2.1 days, but I don't see a reason to make a change at this juncture. Addison > -----Original Message----- > From: John Daggett [mailto:jdaggett@mozilla.com] > Sent: Monday, September 16, 2013 6:56 PM > To: Anne van Kesteren > Cc: Phillips, Addison; Richard Ishida; W3C Style; www International > Subject: Re: [css-fonts-3] i18n-ISSUE-296: Usable characters in unicode-range > > > After re-reading all the posts on this issue, at this point I don't think I see an > issue that requires further consideration. The use of "valid Unicode codepoint" > has been removed from the description of 'unicode-range' in the editor's draft. > > In particular, I think Anne's point about surrogate handling [1] is completely > orthogonal to the behavior of unicode-range: > > > It seems weird to say it expresses a range of Unicode scalar values > > and then include U+D800 to U+DFFF in that range. And let's not use > > "characters" as that's a confusing term. Saying that the range is in > > code points but U+D800 to U+DFFF are ignored (rather than treated as > > an error) could make sense. > > Non-Unicode encoding and surrogate handling issues are dealt with in levels > above the level where font matching occurs. If you look carefully at the > description of font matching, the range of codepoints defined by the 'unicode- > range' descriptor is intersected with the underlying character map of the font. > *That* is what defines the exact set of codepoints that are matched as part of > the font matching algorithm. Given that no font ever includes mappings for > surrogate codepoints to glyphs and no layout engine ever treats lone surrogates > as individual codepoints, I don't see the need to adjust the definition of > 'unicode-range'. Invalid codepoints like this will naturally be ignored given the > existing definition of font matching. > > Regards, > > John Daggett > > [1] http://lists.w3.org/Archives/Public/www-style/2013Sep/0318.html
Received on Tuesday, 17 September 2013 04:43:33 UTC