Previously we had two implementations for parsing
`<color-interpolation-method>`, one for gradients and one for
`color-mix()` - this commit adds another which will unify the existing
ones in following commits.
This implementation has a couple of advantages over the existing ones:
- It is simpler in that it uses global CSS enums and their helper
functions
- It is spec compliant (unlike the `color-mix()` one which allows
arbitrary idents)
- It parses as a `StyleValue` which will be required once we support
`<custom-color-space>` since that can be an `ident()` which isn't
resolvable at parse time
The grammar groups this component together meaning that all
sub-components must occur together i.e.
`ordinal slashed-zero small-caps` is valid but
`ordinal small-caps slashed-zero` is not.
We also reuse the logic for parsing from the longhand
`font-variant-numeric` property for simplicity.
The grammar groups this component together meaning that all
sub-components must occur together i.e.
`common-ligatures no-contextual small-caps` is valid but
`common-ligatures small-caps no-contextual` is not.
We also reuse the logic for parsing from the longhand
`font-variant-ligatures` property for simplicity.
The grammar groups this component together meaning that all
sub-components must occur together i.e. `jis78 full-width small-caps` is
valid but `jis78 small-caps full-width` is not.
We also reuse the logic for parsing from the longhand
`font-variant-east-asian` property for simplicity.
Previously we parsed it as `<custom-ident>` in `<counter>` and as a
keyword in `list-style-type`.
The practical effect of this is:
- Spec defined counter style names in `<counter>` are ASCII lowercased
on parse.
- Non spec defined counter style names are allowed in `list-style-type.
We are still to parse the `symbols()` function but this gives us a
better base for that.
This means we now allow oblique angles when parsing the `font`
shorthand.
This also required us to rename the existing `FontStyle` enum to
`FontStyleKeyword`
As well as being required to implement absolutization this also means we
now bypass a limitation with `LengthPercentage` where we would always
use `SerializationMode::Normal` for the constituent lengths which gains
us some WPT passes
Previously this was implemented inline within the parsing of
`{repeating}-radial-gradient()` functions but it will also be useful for
`circle()` and `ellipse()`.
We now support the CSS Images Module Level 4 additions to the
`<radial-size>` syntax, namely:
- `<length-percentage>` rather than just `<length>` for circles.
- Distinct `<radial-extent>` values for horizontal and vertical for
ellipses.
- Mixing of `<radial-extent>` and `<length-percentage>` values for
ellipses.
The regressions are due to WPT not being updated to expect the first of
these additions.
Storing these within `LengthPercentage`, `LengthBox`, and `Variant`
over-complicated things.
We also now use the correct `SerializationMode` when serializing `xywh`
and `rect`
This works by generating random values using XorShift128PlusRNG at
compute time and then caching them on the document using the relevant
random-caching-key
Previously we would either parse these as `StyleValueList<T>` or `T`
depending on whether or not there was more than one value, this meant we
always had to handle both cases anywhere we used these values.
