parse_a_n_plus_b_pattern()'s job is to parse as much of the TokenStream
as it can as a An+B, and then stop. The caller can then deal with any
trailing tokens as it wishes.
...using a ParseErrorOr type alias.
This lets us replace a bunch of manual error-checking with TRY. :^)
I also replaced the ParsingResult::Done value with returning an
Optional. I wasn't happy with treating "Done" as an error when I first
wrote this, and this makes a clear distinction between the two.
The spec grammar for `text-decoration-line` is:
`none | [ underline || overline || line-through || blink ]`
Which means that it's either `none`, or any combination of the other
values. This patch makes that parse for `text-decoration-line` and
`text-decoration`, stores the results as a Vector, and adjusts
`paint_text_decoration()` to run as a loop over all the values that are
provided.
As noted, storing a Vector of values is a bit wasteful, as they could be
stored as flags in a single `u8`. But I was getting too confused trying
to do that in a nice way.
The goal here is to move the parser-internal classes into this namespace
so they can have more convenient names without causing collisions. The
Parser itself won't collide, and would be more convenient to just
remain `CSS::Parser`, but having a namespace and a class with the same
name makes C++ unhappy.
This is used to skip downloading fonts in formats that we don't support.
Currently we only support TTF as far as I am aware.
The parts of a `src` are in a fixed order, unusually, which makes the
parsing more nesty instead of loopy.
Like, An+B, this is an old construct that does not fit well with modern
CSS syntax, so things get a bit hairy! We have to determine which
tokens match the grammar for `<urange>`, then turn those back into a
string, and then parse the string differently from normal. Thankfully
the spec describes in detail how to do that. :^)
This is not 100% correct, since we are not using the original source
text (referred to in the spec as the "representation") of the tokens,
but just converting them to strings in a manual, ad-hoc way.
Re-engineering the Tokenizer to keep that original text was too much of
a tangent for today. In any case, we do parse `U+4???`, `U+0-100`,
`U+1234`, and similar, so good enough for now!
"Component value" is the term used in the spec, and it doesn't conflict
with any other types, so let's use the shorter name. :^)
Also, this doesn't need to be friends with the Parser any more.
The code had to change a bit to match. Previously, we appended an empty
sub-list immediately, but now we append it at the end. The difference
is that if there are no tokens, we now correctly return an empty
list-of-lists, instead of a list containing an empty list.
We now correctly call convert_to_rule() outside of this function.
As before, I've renamed `parse_as_rule()` -> `parse_as_css_rule()` to
match the free function that calls it.
This is not actually used by anything currently, but it should be used
for `@media` and other at-rules.
Removed the public parse_as_list_of_rules() because public functions
should be things that outside classes actually need to use.
`parse_a_stylesheet()` should not do any conversion on its rules. This
change corrects that. There are other places where we get this wrong,
but one thing at a time. :^)
When parsing the "style" attribute on elements, we'd previously ask the
CSS parser for a PropertyOwningCSSStyleDeclaration. Then we'd create a
new ElementCSSInlineStyleDeclaration and transfer the properties from
the first object to the second object.
This patch teaches the parser to make ElementCSSInlineStyleDeclaration
objects directly.
`text-shadow` does not support this, so this way we can still use the
same parsing code.
It's OK that we still assign a ShadowPlacement value to the
ShadowStyleValue, since it will just get ignored when painting
text-shadows, but if it appears in the property value then that is a
syntax error.
The `text-shadow` property is almost identical to `box-shadow`:
> Values are interpreted as for box-shadow [CSS-BACKGROUNDS-3].
> (But note that the inset keyword are not allowed.)
So, let's use the same data structures and parsing code for both. :^)
In Selectors level 4, `:nth-child()` and `:nth-last-child()` can both
optionally take a selector-list argument. This selector-list acts as a
filter, so that only elements matching the list are counted. For
example, this means that the following are equivalent:
```css
:nth-child(2n+1 of p) {}
p:nth-of-type(2n+1) {}
```
`<forgiving-selector-list>` and `<forgiving-relative-selector-list>` are
the same as regular selector-lists, except that an invalid selector
does not make the whole list invalid. The former is used by the `:is()`
pseudo-class.
For example:
```css
/* This entire selector-list is invalid */
.foo, .bar, !?invalid { }
/* This is valid, but the "!?invalid" selector is removed */
:is(.foo, .bar, !?invalid) { }
```
Also as part of this, I've removed the `parse_a_selector(TokenStream)`
and `parse_a_relative_selector(TokenStream)` methods as they don't add
anything useful.
This resolves the ambiguity between whether a single number is a number
or a ratio. :^)
Also removed the "no more tokens" checks from
deea129b8c - that logic was completely
wrong, since there are always tokens after a value in the `(123 < foo <
456)` syntax.
For now, we only understand `none`, `normal`, `<image>` and `<string>`.
The various other functions and identifiers can be added later.
We can *almost* use a StyleValueList for this, except it's divided into
two parts - the content, and the optional "alt text". So, I've added a
new StyleValue for it.
See https://www.w3.org/TR/css-values-3/#calc-type-checking
If the sub-expressions' types are incompatible, we discard the calc() as
invalid.
Had to do some minor rearranging/renaming of the Calc structs to make
the `resolve_foo_type()` templates work too.
