Problem:
- `(void)` simply casts the expression to void. This is understood to
indicate that it is ignored, but this is really a compiler trick to
get the compiler to not generate a warning.
Solution:
- Use the `[[maybe_unused]]` attribute to indicate the value is unused.
Note:
- Functions taking a `(void)` argument list have also been changed to
`()` because this is not needed and shows up in the same grep
command.
So far we have three different syntax highlighters for LibJS:
- js's Line::Editor stylization
- JS::MarkupGenerator
- GUI::JSSyntaxHighlighter
This not only caused repetition of most token types in each highlighter
but also a lot of inconsistency regarding the styling of certain tokens:
- JSSyntaxHighlighter was considering TokenType::Period to be an
operator whereas MarkupGenerator categorized it as punctuation.
- MarkupGenerator was considering TokenType::{Break,Case,Continue,
Default,Switch,With} control keywords whereas JSSyntaxHighlighter just
disregarded them
- MarkupGenerator considered some future reserved keywords invalid and
others not. JSSyntaxHighlighter and js disregarded most
Adding a new token type meant adding it to ENUMERATE_JS_TOKENS as well
as each individual highlighter's switch/case construct.
I added a TokenCategory enum, and each TokenType is now associated to a
certain category, which the syntax highlighters then can use for styling
rather than operating on the token type directly. This also makes
changing a token's category everywhere easier, should we need to do that
(e.g. I decided to make TokenType::{Period,QuestionMarkPeriod}
TokenCategory::Operator for now, but we might want to change them to
Punctuation.
This adds regex parsing/lexing, as well as a relatively empty
RegExpObject. The purpose of this patch is to allow the engine to not
get hung up on parsing regexes. This will aid in finding new syntax
errors (say, from google or twitter) without having to replace all of
their regexes first!
Adds fully functioning template literals. Because template literals
contain expressions, most of the work has to be done in the Lexer rather
than the Parser. And because of the complexity of template literals
(expressions, nesting, escapes, etc), the Lexer needs to have some
template-related state.
When entering a new template literal, a TemplateLiteralStart token is
emitted. When inside a literal, all text will be parsed up until a '${'
or '`' (or EOF, but that's a syntax error) is seen, and then a
TemplateLiteralExprStart token is emitted. At this point, the Lexer
proceeds as normal, however it keeps track of the number of opening
and closing curly braces it has seen in order to determine the close
of the expression. Once it finds a matching curly brace for the '${',
a TemplateLiteralExprEnd token is emitted and the state is updated
accordingly.
When the Lexer is inside of a template literal, but not an expression,
and sees a '`', this must be the closing grave: a TemplateLiteralEnd
token is emitted.
The state required to correctly parse template strings consists of a
vector (for nesting) of two pieces of information: whether or not we
are in a template expression (as opposed to a template string); and
the count of the number of unmatched open curly braces we have seen
(only applicable if the Lexer is currently in a template expression).
TODO: Add support for template literal newlines in the JS REPL (this will
cause a syntax error currently):
> `foo
> bar`
'foo
bar'
This is required for template literals - we're not quite there yet, but at
least the parser can now tell us when this token is encountered -
currently this yields "Unexpected token Invalid". Not really helpful.
The character is a "backtick", but as we already have
TokenType::{StringLiteral,RegexLiteral} this seemed like a fitting name.
This also enables syntax highlighting for template literals in the js
REPL and LibGUI's JSSyntaxHighlighter.
