Method parse_arguments

crates/ruff_python_parser/src/parser/expression.rs:807–959

Parses an argument list. # Panics If the parser isn't positioned at a `(` token. See:

(&mut self, context: ArgumentsContext)

    ///
    /// See: <https://docs.python.org/3/reference/expressions.html#grammar-token-python-grammar-argument_list>
    pub(super) fn parse_arguments(&mut self, context: ArgumentsContext) -> ast::Arguments {
        let start = self.node_start();
        self.bump(TokenKind::Lpar);

        if self.eat(TokenKind::Rpar) {
            return ast::Arguments {
                range: self.node_range(start),
                node_index: AtomicNodeIndex::NONE,
                args: Box::default(),
                keywords: ThinVec::default(),
            };
        }

        let args_snapshot = self.expr_scratch.snapshot();
        let keywords_snapshot = self.keyword_scratch.snapshot();
        let mut seen_keyword_argument = false; // foo = 1
        let mut seen_keyword_unpacking = false; // **foo

        let has_trailing_comma =
            self.parse_comma_separated_list(RecoveryContextKind::Arguments, |parser| {
                let argument_start = parser.node_start();
                if parser.eat(TokenKind::DoubleStar) {
                    let value = parser.parse_conditional_expression_or_higher();

                    parser.keyword_scratch.push(ast::Keyword {
                        arg: None,
                        value: value.expr,
                        range: parser.node_range(argument_start),
                        node_index: AtomicNodeIndex::NONE,
                    });

                    seen_keyword_unpacking = true;
                } else {
                    let start = parser.node_start();
                    let mut parsed_expr = parser
                        .parse_named_expression_or_higher(ExpressionContext::starred_conditional());

                    match parser.current_token_kind() {
                        TokenKind::Async | TokenKind::For => {
                            if parsed_expr.is_unparenthesized_starred_expr() {
                                parser.add_unsupported_syntax_error(
                                    UnsupportedSyntaxErrorKind::UnpackingInComprehension(
                                        ComprehensionUnpackingKind::IterableInGenerator,
                                    ),
                                    parsed_expr.range(),
                                );
                            }

                            parsed_expr = Expr::Generator(parser.parse_generator_expression(
                                parsed_expr.expr,
                                start,
                                Parenthesized::No,
                            ))
                            .into();
                        }
                        _ => {
                            if seen_keyword_unpacking
                                && parsed_expr.is_unparenthesized_starred_expr()