Parsing this pattern from CSS tokens turns out to be slightly crazy, but
thankfully well documented in the spec.
The spec lists the cases in order of simple -> complicated, but this
would cause problems in code, since `<n-dimension> <signed-.integer>`
would never by reached, as `<n-dimension>` comes before. Instead, I
have grouped them by their first token.
Also renamed the NthChildPattern class to ANPlusBPattern, to match spec
terminology.
The spec does not directly tell us how to parse selectors, so there are
likely some bugs here, but I've used the spec language where possible.
This is very much based on the previous selector parsing code.
Any parse error inside a selector makes the entire SelectorList
invalid, so nothing is returned.
Also added css-import.html, which tests the 3 syntax variations on
`@import` statements. Note that the optional media-query parameter to
`@import` is not handled yet.
This was broken when we switched away from using StringStyleValues.
While I was at it, I have implemented hsl/a() and the percentage
syntax for rgb/a().
As a bonus, added `colors.html` as a test page for the various CSS
color syntaxes, since nothing was testing rgb() or rgba() before.
Much of the parsing code in LibGFX/Color.h seems to be centered
around CSS color values, but this is not used by the new Parser.
(And can't be used, because it requires a String value and we have
a list of Tokens of some kind instead.) Maybe that should be removed
from there when the new CSS parser is operational.
Had to adjust some places that were using Token.to_string() for
non-debug-logging purposes. Changed its name to to_debug_string()
to make the usage clearer.
The end goal here is to make the two classes mostly interchangeable, as
the CSS spec requires that the various parser algorithms can take a
stream of either class, and we want to have that functionality without
needing to duplicate all of the code.
We had some inconsistencies before:
- Sometimes "The", sometimes "the"
- Sometimes trailing ".", sometimes no trailing "."
I picked the most common one (lowecase "the", trailing ".") and applied
it to all copyright headers.
By using the exact same string everywhere we can ensure nothing gets
missed during a global search (and replace), and that these
inconsistencies are not spread any further (as copyright headers are
commonly copied to new files).
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
