Implement try_batch

[nikis05]

futures::stream::TryStreamExt has a try_chunks method that batches Ok values and immediately propagates any Err values. I believe it would be very useful to have something like that in this library.

[mre]

Indeed. Would you like to give this a try?

[mre]

For some guidance, you'd have to copy the code from https://github.com/rust-lang/futures-rs/blob/master/futures-util/src/stream/try_stream/try_chunks.rs and add the timeout as we do for the normal ChunksTimeout.
Maybe create a separate module for it, so at the end we have

• lib.rs (just imports chunks and try_cunks)
• chunks.rs (the current code in lib.rs)
• try_chunks.rs (the new code)

Ideally, add some tests as well. 😃

[nikis05]

@mre sounds good, I’ll give it a try