viirya commented on issue #5098: URL: https://github.com/apache/arrow-rs/issues/5098#issuecomment-1817930466
> I'm not sure of the history here, but the current design does allow for some advantages when the types are known ahead of time If we know the row column types in compile time, it is okay as shown in the example `i32_list: ListBuilder<Int32Builder>`. But we don't know the types in compile time, that being said we have arbitrary column types of rows and `ListBuilder` could be deeply nested. I'm not sure how to get the deeply nested type parameter in runtime, i.e., `ListBuilder<ListBuilder<ListBuilder<...>>>` Currently I can use macro to create `ListBuilder<T>` for T as primitive and struct types because they don't have type parameters. So any situation that needs to have `ListBuilder<T>` as parameter, it is impossible (I am not sure, at least I don't find a way) to have it in arbitrarily nested structure, because of the generic type parameter `T`. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
