[webkit-dev] Request for Position on :has() pseudo class

[Byungwoo Lee]

Hello WebKit devs,

This is a request for getting position on the :has() pseudo class.

The :has() pseudo class is a selector that specifies elements which has 
at least one element that matches the relative selector passed as an 
argument. (https://www.w3.org/TR/selectors-4/#relational)

Unlike other selectors, it gives a way to apply a style rule to 
preceding elements (preceding siblings / ancestors / preceding siblings 
of ancestors) of a certain elements.

This difference is attractive to web developers, but also it generates 
lots of concerns mainly about performance and complexity.

We thought that, clarifying those concerns would be helpful for the 
discussion. So we started to check feasibility on blink, and were able 
to get some meaningful and reasonable results from this step. Based on 
the results, we are going to move forward by prototyping.

You can get the details about the current status in here.
* Explainer: https://github.com/Igalia/explainers/tree/main/css/has
* Test summary: https://css-has.glitch.me/

Regards,
Byungwoo