viirya commented on pull request #1367:
URL: https://github.com/apache/arrow-rs/pull/1367#issuecomment-1054982569
> Today if people `impl Borrow<i8> for MyAwesomeType` then I think
(untested) they can create arrays from an iterator of `MyAwesomeType` which
they might not be able to do after this PR 🤔 Though perhaps they just need to
implement `ArrowPrimitiveTypeNative`
I guess you mean `impl Borrow<Option<i8>> for MyAwesomeType`? Yes, this is a
concern. People need to implement `impl From<MyAwesomeType> for
ArrowPrimitiveTypeNative<Int8Type>`.
> I tried a little to figure out a clever way to implement the conversion
using a trait that is a superset of `Borrow` to make it backwards compatible
and more general. Thus instead of
>
> ```rust
> impl<T: ArrowPrimitiveType, Ptr: Borrow<Option<<T as
ArrowPrimitiveType>::Native>>>
> FromIterator<Ptr> for PrimitiveArray<T>
> ```
>
> It would look something like
>
> ```rust
> impl<T: ArrowPrimitiveType, Ptr: BorrowAsOption<<T as
ArrowPrimitiveType>::Native>>
> FromIterator<Ptr> for PrimitiveArray<T>
> ..
>
> pub trait BorrowAsOption<T: ArrowPrimitiveType> {
> fn as_native(&self) -> Option<&<T as ArrowPrimitiveType>::Native>;
> }
> ```
>
> But my mind was being blown by type errors.
Not sure if I understand above way. Seems people still need to implement
`BorrowAsOption`, so it's still not backwards compatible.
--
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]
