frappe - FRP library for Rust

Functional Reactive Programming library inspired by Carboxyl. It's designed to efficiently pass objects around by avoiding cloning as much as possible, and by evaluating signals only when changes happen. Threading is not directly supported, but there are methods that interface with channels.

Documentation

Usage

extern crate frappe;
use frappe::Sink;

fn main()
{
    // values are sent from a sink..
    let sink = Sink::new();
    // ..into a stream chain
    let stream = sink.stream()
        .inspect(|a| println!("--sent: {}", a));

    // `hold` creates a Signal that stores the last value sent to the stream
    let last = stream.hold(0);
    // filter/map/fold are analogous to Iterator operations
    // most callbacks receive a MaybeOwned<T> argument, so we need to deref the value
    let sum = stream.fold(0, |acc, n| acc + *n);
    let half_even = stream
        .filter(|n| n % 2 == 0)
        .map(|n| *n / 2)
        .collect::<Vec<_>>();

    // can send individual values
    sink.send(6);
    sink.send(42);
    sink.send(-1);
    // or multiple at once
    sink.feed(10..15);

    // `sample` gets a copy of the value stored in the signal
    println!("last: {}", last.sample());
    // printing a signal samples it
    println!("sum: {}", sum);
    // `sample_with` gets a reference to the internal value, no clone needed
    half_even.sample_with(|v| println!("half_even: {:?}", v));
}