Documentation for the master branch
Tail-call elimination for futures.
Dispatching a long chain of futures built with and_then may result in a
linear cost. One could avoid this using e.g. loop_fn, but this is hard to
compose due to shared state.
This package provides an alternative interface through a Become construct,
which acts as a kind of "tail-call elimination" at the futures level. Turns
out it can be done without modifying the existing Future trait, but at the
cost of changing Error type of each future to a wrapped one using Become.
Then, returning Err(Become::Become(next)) can be used to indicate that the
current future should be discarded and replaced with next. This of course
means that we have to box each future, as the type of the current future could
be wildly different from that of the next future.