Method parse_named_expression

crates/ruff_python_parser/src/parser/expression.rs:2922–2954

Parses a named expression (`:=`). # Panics If the parser isn't positioned at a `:=` token. See:

(
        &mut self,
        mut target: Expr,
        start: TextSize,
    )

    ///
    /// See: <https://docs.python.org/3/reference/expressions.html#assignment-expressions>
    pub(super) fn parse_named_expression(
        &mut self,
        mut target: Expr,
        start: TextSize,
    ) -> ast::ExprNamed {
        self.bump(TokenKind::ColonEqual);

        if !target.is_name_expr() {
            self.add_error(ParseErrorType::InvalidNamedAssignmentTarget, target.range());
        }
        helpers::set_expr_ctx(&mut target, ExprContext::Store);

        let value = self.parse_conditional_expression_or_higher();

        let range = self.node_range(start);

        // test_err walrus_py37
        // # parse_options: { "target-version": "3.7" }
        // (x := 1)

        // test_ok walrus_py38
        // # parse_options: { "target-version": "3.8" }
        // (x := 1)

        self.add_unsupported_syntax_error(UnsupportedSyntaxErrorKind::Walrus, range);

        ast::ExprNamed {
            target: Box::new(target),
            value: Box::new(value.expr),
            range,
            node_index: AtomicNodeIndex::NONE,
        }
    }

    /// Parses a lambda expression.
    ///