[css-selectors-4] Syntax order of `<pseudo-compound-selectors>`

[pyoor]

Currently the syntax for pseudo-compound-selectors is defined as:

csswg-drafts/selectors-4/Overview.bs

Line 3602 in c63d003

<dfn>&lt;pseudo-compound-selector></dfn> = <<pseudo-element-selector>> <<pseudo-class-selector>>*

However, according to the following note, pseudo-elements rarely follow pseudo-classes and the inverse is more often true.

[In general, a <pseudo-element-selector> is only valid if placed at the end of the last <compound-selector> in a <complex-selector>. In some circumstances, however, it can be followed by more s or <pseudo-class-selector>s; but these are specified on a case-by-case basis. (For example, the user action pseudo-classes are allowed after any pseudo-element, and the tree-abiding pseudo-elements are allowed after the ::slotted() pseudo-element.)](

csswg-drafts/selectors-4/Overview.bs

Lines 3673 to 3682 in c63d003

	Note: In general,
	a <<pseudo-element-selector>> is only valid
	if placed at the end of the last <<compound-selector>>
	in a <<complex-selector>>.
	In some circumstances, however,
	it can be followed by more <<pseudo-element-selector>>s or <<pseudo-class-selector>>s;
	but these are specified on a case-by-case basis.
	(For example, the <a>user action pseudo-classes</a> are allowed after any <a>pseudo-element</a>,
	and the <a>tree-abiding pseudo-elements</a>
	are allowed after the ''::slotted()'' pseudo-element.)

)

Shouldn't the syntax of pseudo-compound-selectors be changed to reflect this? Or, should the syntax be changed to use && combinator to denote that they may appear in any order?

[Loirooriol]

pseudo-elements rarely follow pseudo-classes and the inverse is more often true.

No, it's the other way round.

Shouldn't the syntax of pseudo-compound-selectors be changed to reflect this?

No. <pseudo-compound-selector> covers pseudo-classes after pseudo-element. <compound-selector> covers pseudo-elements after pseudo-classes.

[pyoor]

No. <pseudo-compound-selector> covers pseudo-classes after pseudo-element. <compound-selector> covers pseudo-elements after pseudo-classes.

I don't believe that's correct. I see no reference to <pseudo-element-selector> in the <compound-selector> syntax or any subsequent syntax referenced by it. Can you point me to where that's defined?

[Loirooriol]

I meant <complex-selector-unit> has the <compound-selector> with the pseudo-class, followed by the <pseudo-compound-selector> with the pseudo-element.

[pyoor]

Ah, ok - I see. Thanks for the explanation.