feat(css_parser): CSS Parser pseudo element selector #268

[denbezrukov]

Summary

Change part and highlight syntax, they have identifies as a parameter:
https://developer.mozilla.org/en-US/docs/Web/CSS/::part
https://developer.mozilla.org/en-US/docs/Web/CSS/::highlight

Test Plan

cargo test

[github-actions]

Parser conformance results on

js/262

Test result	main count	This PR count	Difference
Total	49701	49701	0
Passed	48720	48720	0
Failed	981	981	0
Panics	0	0	0
Coverage	98.03%	98.03%	0.00%

jsx/babel

Test result	main count	This PR count	Difference
Total	40	40	0
Passed	37	37	0
Failed	3	3	0
Panics	0	0	0
Coverage	92.50%	92.50%	0.00%

symbols/microsoft

Test result	main count	This PR count	Difference
Total	6322	6322	0
Passed	2036	2036	0
Failed	4286	4286	0
Panics	0	0	0
Coverage	32.20%	32.20%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	662	662	0
Passed	592	592	0
Failed	70	70	0
Panics	0	0	0
Coverage	89.43%	89.43%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	17646	17646	0
Passed	13454	13454	0
Failed	4190	4190	0
Panics	2	2	0
Coverage	76.24%	76.24%	0.00%

[denbezrukov]

I'm not sure if it is the best way how to handle it.
Because now we have an invariant over a parameter and we have to unwrap it for cases where an identifier is invalid.
We can try to introduce more a comprehensive syntax for part and highlight.
what do you think?

[ematipico]

I'm not sure if it is the best way how to handle it. Because now we have an invariant over a parameter and we have to unwrap it for cases where an identifier is invalid. We can try to introduce more a comprehensive syntax for part and highlight. what do you think?

Having worked on a CSS parser before, I know their grammar is very strict, and most of the time they apply rules to very specific parts of the grammar, e.g. calc, which is a function but it has very strict rules about what's inside it

My gut feeling tells me that we should implement specific grammar/parsing whenever we can, and try to avoid applying "generic" functions/nodes/patterns whenever we can.