Re: [shadowdom]: Using :root to specify the insertion point in ::distributed

• From: Hayato Ito <hayato@google.com>
• Date: Tue, 26 Mar 2013 12:35:57 +0900
• To: www-style@w3.org
• Message-ID: <CAFpjS_0h8qcDoY9etVy1jG=1yYVJW-bY2-h_Xu7tWNOCLPoPLQ@mail.gmail.com>

I think the suggested proposal has a weak point from the view of CSS
selector's sementics.

The suggested proposal,

  (A) :root > *

should be equivalent with:

  (B) *:root > *

The left side of ':root', '*', is just omitted in this case.

Since an effect of a pseudo class should be just filtering elements,
a set of elements which (B) matches should be a subset of elements
which (C), the following, matches.

  (C)  * > *


A '::distributed' functional pseudo element is expected to take a
selector in its parameter.
Therefore, given the following (D) and (E),

  (D)  a set of elements which '::distributed(*:root > *)' matches
  (E)  a set of elements which '::distributed(* > *)' matches

(D) should be a subset of (E) from the view of CSS selector's semantics.
But looks like the suggested proposal could not meet this.


Note that I've just subscribed this ML, so this mail does not have an
in-reply-to header.

--
Hayato

Received on Tuesday, 26 March 2013 09:05:36 UTC