When I added these tests, they didn't find any bugs in my own
implementation, but I did find a bug in futures::future::unfold.
See the in-code comment.
This is a general-purpose implementation of the ad-hoc approach
currently taken in (eg) crates/tor-proto/src/channel/reactor.rs,
with an API intended to defned against the more obvious mistakes.
This allows us to separate the two concerns: the channel reactor can
focus on handling channel cells and control messages and is over 2.5x
shorter.
The complexity of the manual sink implementation, and the machinery
needed to avoid having to suspend while holding an item, are dealt
with separately. That separate implemenation now has proper
documentation. (Tests are in the nest commit to avoid this one being
even more unwieldy.)
We use `extend` to define this as an extension trait. A competitor is
`ext` but in my personal projects I have found `extend` slightly
better.
Previously the code would do stuff like
```
schedule = RetrySchedule::new(INITIAL_DELAY);
```
which is needlessly verbose, since the schedule already keeps track
of its initial delay.
The doc include rune does not work with our MSRV; it needs 1.54.
The alternative would be some kind of cfg() but that would
- not provide the crate-level doc on Rust 1.53
- involve the use of cfg_attr
Instead, just do it the old way.
Ian Jackson
Samanta Navarro
Nick Mathewson