Extended CSS value definitions

[cdoublev]

When a spec extends a production rule whose LHS links to its definition in another spec, reffy reports it as a dangling production rule:

• <color-mix()>
• <cross-fade()>
• <keyframe-selector>
• <radial-size>

Do you think they could escape this segregation and move to the global values?

I presume this would require parsing the link before extracting the text content, and carry it forward to set rule.href, which does not seem ideal.

I also do not know if the extracted definition href would need to point to the other spec.

[tidoust]

Do you think they could escape this segregation and move to the global values?

Yes, that would seem a good thing to do.

There should be a way to tell that this is an extension of a base definition. For properties, we have newValues. Perhaps we could record the syntax in a newValue property here, although I note that the semantics are slightly different: for newValues, these are additional values, whereas the extension here seems to always overwrite the base definition.

I presume this would require parsing the link before extracting the text content, and carry it forward to set rule.href, which does not seem ideal.

An additional complication is that these <pre> blocks may contain more than one production rule :( That is what the split on reSplitLines a couple of lines after the one you referenced attempts to take care of:

reffy/src/browserlib/extract-cssdfn.mjs

Lines 568 to 574 in 30ab8e1

	/**
	* Regular expression used to split production rules:
	* Split on the space that precedes a term immediately before an equal sign
	* that is not wrapped in quotes (an equal sign wrapped in quotes is part of
	* actual value syntax)
	*/
	const reSplitRules = /\s(?=[^\s]+?\s*?=[^'])/;

I also do not know if the extracted definition href would need to point to the other spec.

For property extensions, we simply do not put capture any href. I would suggest to do the same.