Kang-Hao (Kenny) Lu

Some of the (hypothetical) user scenario: 1. A tinycss UA developer (meaning that he/she is unwilling to build a completely new parser from scratch) wants to support CSS variables/hierarchy before...

> I think that this feature is all that is needed in the parser for both 2 and 3. The difference between those is "just" whether to remove or add...

> The `ParseError` exception is an internal flow control mechanism. It means “Ignore this declaration or rule.” Yeah, I sort of learn that. What I am trying to say is...

> When media queries are not supported, `@import` is defined in 6.3 of CSS 2.1. The normative prose there matches the informative grammar in Appendix G: These as far as...

> And also, I believe how malformed Declaration list is handled is more of an orthogonal issue so I think it's quite unhelpful to conflate the two. Oh, I just...

> where `` is any list of tokens (and may be empty) That does seem to make `parse_media` more self-contained! > However, having an `@media` rule with 'not all' is...

Oh, I just realized that the best way for a CSS 2.1 UA seems to be following the HTML4 rules as [quoted](http://dev.w3.org/csswg/css3-mediaqueries/#background) in css3-mediaquries: extract the first token if it's...

> I can’t find any reference to HTML4’s media descriptors in CSS 2.1. Hmm... yeah, it's a bit weird, but anyway. Gecko implements the HTML4 rules before Media Quries are...

The use case for 1. is admittedly very weak, unless people do `@media print and (width: xxx), print` for backwards compatibility, which I believe to be quite unlikely. The use...