[css-fonts-4] Group sub-property related symbols in font-variant value definition

[cdoublev]

If the following change is not against any non-defined rules applying to the CSS value definition syntax, I would like each font-variant sub-properties to have its corresponding symbols grouped (between []) in the font-variant value definition.

A CSS parser could automatically output a nested list of the component values matching the grouped symbols. This would avoid coupling the expansion function of font-variant to its current value definition.

    normal 
  | none 
  | [
-        <common-lig-values> || <discretionary-lig-values> || <historical-lig-values> || <contextual-alt-values> 
+        [<common-lig-values> || <discretionary-lig-values> || <historical-lig-values> || <contextual-alt-values>]
      || [small-caps | all-small-caps | petite-caps | all-petite-caps | unicase | titling-caps] 
      || [
              stylistic(<feature-value-name>) 
           || historical-forms 
           || styleset(<feature-value-name>#) 
           || character-variant (<feature-value-name>#) 
           || swash(<feature-value-name>) 
           || ornaments(<feature-value-name>) 
           || annotation(<feature-value-name>)
         ] 
-     || <numeric-figure-values> || <numeric-spacing-values> || <numeric-fraction-values> || ordinal || slashed-zero 
+     || [<numeric-figure-values> || <numeric-spacing-values> || <numeric-fraction-values> || ordinal || slashed-zero]
-     || <east-asian-variant-values> || <east-asian-width-values> || ruby 
+     || [<east-asian-variant-values> || <east-asian-width-values> || ruby]
      || [sub | super] 
      || [text | emoji | unicode] 
   ]

[svgeesus]

That seems reasonable to me