This library seeks to fully, effectively and simply recreate lightweight Javascript-style promises in Rust.
rust-promises offers all the features of Ecmascript 6 promises plus a few Rust methods from Result<T, E>, implemented using the std::thread API and
Rust's asyncronous Sender and Receiver.
TODO (after adding some Result methods to Promise).
Promises are an excellent building block for asyncronous programming. They're a great way to build an asyncronous library, and also a small dependency for existing code.
Javascript's promises were adapted from promises in a programming language called E, which has a very powerful distributed computing architecture using message passing.
Rust's std::sync::mpsc::{Sender, Receiver} provide a way to build such an
architecture (and promises) from Rust's safe threading systems.
There are currently 5 asyncronous libraries on crates.io which offer promises
or futures. However they all have problems:
* ~~They are all in beta and unstable, with versions < 0.5~~ (like this library right now...)
* Some of them are larger async libraries. They require programming within
event loops, or are designed for specific scenarios. If you want a whole async
library for a specific type of programming, go use those.
* The rest are variations on the promise concept, i.e. returning a (Future, Promise) pair from Promise::new(). If you know how to use that, go to those libraries, I guess.