Method visit_stmt

crates/ruff_python_parser/src/semantic_errors.rs:871–911

Check `stmt` for semantic syntax errors and update the checker's internal state. Note that this method should only be called when traversing `stmt` *and* its children. For example, if traversal of function bodies needs to be deferred, avoid calling `visit_stmt` on the function itself until the deferred body is visited too. Failing to defer `visit_stmt` in this case will break any internal state t

(&mut self, stmt: &ast::Stmt, ctx: &Ctx)

    /// this case will break any internal state that depends on function scopes, such as `async`
    /// context detection.
    pub fn visit_stmt<Ctx: SemanticSyntaxContext>(&mut self, stmt: &ast::Stmt, ctx: &Ctx) {
        // check for errors
        self.check_stmt(stmt, ctx);

        // update internal state
        match stmt {
            Stmt::Expr(StmtExpr { value, .. })
                if !self.seen_module_docstring_boundary && value.is_string_literal_expr() => {}
            Stmt::ImportFrom(StmtImportFrom {
                module, is_lazy, ..
            }) => {
                // Allow eager `__future__` imports until we see any other import. Lazy imports,
                // including `lazy from __future__ import ...`, always close the boundary.
                if *is_lazy || !matches!(module.as_deref(), Some("__future__")) {
                    self.seen_futures_boundary = true;
                }
            }
            Stmt::FunctionDef(StmtFunctionDef { is_async, body, .. }) => {
                if *is_async {
                    let mut visitor = ReturnVisitor::default();
                    visitor.visit_body(body);

                    if visitor.has_yield {
                        if let Some(return_range) = visitor.return_range {
                            Self::add_error(
                                ctx,
                                SemanticSyntaxErrorKind::ReturnInGenerator,
                                return_range,
                            );
                        }
                    }
                }
                self.seen_futures_boundary = true;
            }
            _ => {
                self.seen_futures_boundary = true;
            }
        }

        self.seen_module_docstring_boundary = true;
    }

    /// Check `expr` for semantic syntax errors and update the checker's internal state.
    pub fn visit_expr<Ctx: SemanticSyntaxContext>(&mut self, expr: &Expr, ctx: &Ctx) {