[w3ctag/design-reviews] CSS Values and Units: sibling-count() and sibling-index() (Issue #1068)

lilles created an issue (w3ctag/design-reviews#1068)

こんにちは TAG-さん!

I'm requesting a TAG review of CSS Values and Units: sibling-count() and sibling-index().

The CSS Values and Units Module Level 5 introduces [tree counting functions](https://drafts.csswg.org/css-values-5/#tree-counting), specifically `sibling-index()` and `sibling-count()`. These functions can be used as `<integer>` values directly or combined with other values in calc() expressions. The `sibling-index()` and `sibling-count()` functions evaluate to integers at computed value time based on the flat tree position of the element.

  - Explainer¹: https://github.com/w3c/csswg-drafts/blob/main/css-values-5/tree-counting-explainer.md
  - Specification: https://drafts.csswg.org/css-values-5/#tree-counting
  - WPT Tests: https://wpt.fyi/results/css/css-values/tree-counting
  - User research:
  - Security and Privacy self-review²:
  - GitHub repo: https://github.com/w3c/csswg-drafts
  - Primary contacts:
      - @lilles, Google, Implementer
      - @tabatkins, Google, Editor
  - Organization/project driving the specification: CSSWG
  - Multi-stakeholder support³:
    - Chromium comments: Implementation in progress behind a flag
    - Mozilla comments: https://github.com/mozilla/standards-positions/issues/1194
    - WebKit comments: https://github.com/WebKit/standards-positions/issues/471
    - Links to articles [in the explainer](https://github.com/w3c/csswg-drafts/blob/main/css-values-5/tree-counting-explainer.md#resources)
    - Some developer reactions: [bsky](https://bsky.app/profile/nerdy.dev/post/3lk2twv34rk2a)
  - Status/issue trackers for implementations⁴:
    - https://chromestatus.com/feature/6225478530367488
    - https://crbug.com/40282719
    - https://bugzilla.mozilla.org/show_bug.cgi?id=1953973

Further details:

  - [X] I have reviewed the TAG's [Web Platform Design Principles](https://www.w3.org/TR/design-principles/)
  - The group where the work on this specification is currently being done: CSSWG

You should also know that there are open issues to extend tree-counting functions:
  - [Additional support for light tree counting](https://github.com/w3c/csswg-drafts/issues/9562)
  - [Add selector argument](https://github.com/w3c/csswg-drafts/issues/9572)
  - [Add children-count() function](https://github.com/w3c/csswg-drafts/issues/11068)
  - [Add descendant-count() function](https://github.com/w3c/csswg-drafts/issues/11069)


-- 
Reply to this email directly or view it on GitHub:
https://github.com/w3ctag/design-reviews/issues/1068
You are receiving this because you are subscribed to this thread.

Message ID: <w3ctag/design-reviews/issues/1068@github.com>