- From: Simon Pieters <simonp@opera.com>
- Date: Tue, 30 Sep 2014 12:05:54 +0200
- To: www-style@w3.org
What is the correct interpretation of this grammar: a? | b If a is omitted, it does not occur (or occurs zero times), but | requires one of them to occur, so my understanding is that the above is equivalent to: a | b http://dev.w3.org/csswg/css-values/#mult-opt http://dev.w3.org/csswg/css-values/#comb-one Either way, it's confusing. Please make it clearer. This is relevant for http://dev.w3.org/csswg/mediaqueries-4/#typedef-media-query In particular, consider this media query list: "," If the empty string matches <media-query> production then there are two empty <media-query>s (it's not defined if it matches or not AFAICT). If the empty string does not match <media-query> production then it's equivalent to "not all,not all" per the error recovery rules (this matches Trident/WebKit/Blink/Gecko/Presto). http://software.hixie.ch/utilities/js/live-dom-viewer/saved/3216 If the interoperable browser behavior is intended, please remove the question mark. -- Simon Pieters Opera Software
Received on Tuesday, 30 September 2014 10:12:01 UTC