Rust Generators

generators.rs

#![allow(unused)]
#![feature(generators, generator_trait)]

use std::ops::{Generator, GeneratorState};

fn main() {
    let mut generator = || {
        yield 1;
        return "foo"
    };

    match unsafe { generator.resume() } {
        GeneratorState::Yielded(one) => { println!("{}", one) }
        _ => panic!("unexpected return from resume"),
    }
    match unsafe { generator.resume() } {
        GeneratorState::Complete(returned) => { println!("{}", returned)}
        _ => panic!("unexpected return from resume"),
    }
}

Generators, also commonly referred to as coroutines, are currently an experimental language feature in Rust. Added in RFC 2033 generators are currently intended to primarily provide a building block for async/await syntax but will likely extend to also providing an ergonomic definition for iterators and other primitives.

The syntax and semantics for generators is unstable and will require a further RFC for stabilization. At this time, though, the syntax is closure-like:

doc here