# rx-rust
Reactive Extensions for Rust. `rx-rust` offers a comprehensive, zero-unsafe toolkit for composing asynchronous and event-driven programs by chaining observables and operators in a declarative style inspired by [ReactiveX](https://reactivex.io/).
## Installation
`rx-rust` is a regular Cargo library crate. Add it to your project like any other dependency:
```toml
[dependencies]
rx-rust = { version = "the_latest_version", features = ["tokio-scheduler"] } # Use tokio runtime
rx-rust = { version = "the_latest_version", features = ["async-std-scheduler"] } # Use async-std runtime
rx-rust = { version = "the_latest_version", features = ["thread-pool-scheduler"] } # Use futures thread pool
rx-rust = { version = "the_latest_version", features = ["tokio-scheduler"] } # Use futures local pool
```
### Feature Flags
`multi-threaded` (default) | Core operators with `Send`-friendly observables. | –
`single-threaded` | Core operators optimised for single-threaded use. | –
`local-pool-scheduler` | Scheduler backed by `futures` local pool (enable for `Interval`, `Timer`, etc.). | `single-threaded`, `futures`, `async-io`
`thread-pool-scheduler` | Scheduler backed by `futures` thread pool. | `futures/thread-pool`, `async-io`
`tokio-scheduler` | Scheduler integration for Tokio runtimes. | `futures`, `tokio/rt`, `tokio/time`
`async-std-scheduler` | Scheduler based on async-std. | `futures`, `async-std`
## Quick Start
Build pipelines by combining operators from `ObservableExt` and subscribe with callbacks or custom observers.
```rust
use rx_rust::observable::observable_ext::ObservableExt;
use rx_rust::observer::Termination;
use rx_rust::operators::creating::range::Range;
Range::new(1..=5)
.map(|value| value * 2)
.filter(|value| *value % 3 == 0)
.subscribe_with_callback(
|value| println!("next: {value}"),
|termination| println!("done: {termination:?}"),
);
```
### Scheduling Example
Time-based operators require a scheduler. The example below uses Tokio; similar code works with the other scheduler features.
```rust
#[tokio::main]
async fn main() {
use rx_rust::{
observable::observable_ext::ObservableExt,
observer::Termination,
operators::{
creating::from_iter::FromIter,
utility::delay::Delay,
},
};
use std::{
sync::{Arc, Mutex},
time::Duration,
};
use tokio::time::sleep;
let handle = tokio::runtime::Handle::current();
let values = Arc::new(Mutex::new(Vec::new()));
let terminations = Arc::new(Mutex::new(Vec::new()));
let values_observer = Arc::clone(&values);
let terminations_observer = Arc::clone(&terminations);
let subscription = Delay::new(
FromIter::new(vec![1, 2, 3]),
Duration::from_millis(5),
handle.clone(),
)
.subscribe_with_callback(
move |value| values_observer.lock().unwrap().push(value),
move |termination| terminations_observer
.lock()
.unwrap()
.push(termination),
);
sleep(Duration::from_millis(10)).await;
drop(subscription);
assert_eq!(&*values.lock().unwrap(), &[1, 2, 3]);
assert_eq!(
&*terminations.lock().unwrap(),
&[Termination::Completed]
);
}
```
## Project Layout
- `src/observable` – Core observable traits and the `ObservableExt` extension trait that wires in every operator.
- `src/operators` – Operator implementations grouped by category (`creating`, `transforming`, `combining`, `utility`, and more) to mirror ReactiveX terminology.
- `src/subject` – Subjects bridging observers and observables for multicast workflows.
- `src/scheduler` – Scheduler abstractions and adapters for popular async executors.
- `tests/` – Exhaustive conformance tests covering each operator; great as executable documentation.