futures-preview 0.3.0-alpha.18

An implementation of futures and streams featuring zero allocations, composability, and iterator-like interfaces.

Abstractions for asynchronous programming.

This crate provides a number of core abstractions for writing asynchronous code:

  • Futures are single eventual values produced by asynchronous computations. Some programming languages (e.g. JavaScript) call this concept "promise".
  • Streams represent a series of values produced asynchronously.
  • Sinks provide support for asynchronous writing of data.
  • Executors are responsible for running asynchronous tasks.

The crate also contains abstractions for asynchronous I/O and cross-task communication.

Underlying all of this is the task system, which is a form of lightweight threading. Large asynchronous computations are built up using futures, streams and sinks, and then spawned as independent tasks that are run to completion, but do not block the thread running them.