Carboxyl is a library for functional reactive programming in Rust, a functional and composable approach to handle events in interactive applications. Read more in the docs…
Here is a simple example of how you can use the primitives provided by Carboxyl. First of all, events can be sent into a sink. From a sink one can create a stream of events. Streams can also be filtered, mapped and merged. A signal is an abstraction of a value that may change over time. One can e.g. hold the last event from a stream in a signal.
```rust extern crate carboxyl;
fn main() { let sink = carboxyl::Sink::new(); let stream = sink.stream(); let signal = stream.hold(3);
// The current value of the signal is initially 3
assert_eq!(signal.sample(), 3);
// When we fire an event, the signal get updated accordingly
sink.send(5);
assert_eq!(signal.sample(), 5);
} ```
One can also directly iterate over the stream instead of holding it in a signal:
```rust extern crate carboxyl;
fn main() { let sink = carboxyl::Sink::new(); let stream = sink.stream();
let mut events = stream.events();
sink.send(4);
assert_eq!(events.next(), Some(4));
} ```
Streams and signals can be combined using various primitives. We can map a stream to another stream using a function:
```rust extern crate carboxyl;
fn main() { let sink = carboxyl::Sink::new(); let stream = sink.stream();
let squares = stream.map(|x| x * x).hold(0);
sink.send(4);
assert_eq!(squares.sample(), 16);
} ```
Or we can filter a stream to create a new one that only contains events that satisfy a certain predicate:
```rust extern crate carboxyl;
fn main() { let sink = carboxyl::Sink::new(); let stream = sink.stream();
let negatives = stream.filter(|&x| x < 0).hold(0);
// This won't arrive at the signal.
sink.send(4);
assert_eq!(negatives.sample(), 0);
// But this will!
sink.send(-3);
assert_eq!(negatives.sample(), -3);
} ```
There are a couple of other primitives to compose streams and signals:
merge two streams of events of the same type.snapshot of a signal, whenever a stream fires an event.lift! an ordinary function to a function on signals.switch between different signals using a signal containing a signal.See the documentation for details.
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