Crate gen_iter

gen_iter - create generators to use as iterators

GenIter and gen_iter!

GenIter converts a Generator<(), Return=()> into an iterator over the yielded type of the generator. The return type of the generator needs to be ().

gen_iter! helps to create a GenIter

#![feature(generators)]

use gen_iter::gen_iter;

fn fibonacci() -> impl Iterator<Item = u64> {
    gen_iter!({
        let mut a = 0;
        let mut b = 1;

        loop {
            let c = a + b;
            a = b;
            b = c;

            yield a;
        }
    })
}

for elem in fibonacci().map(|x| 2 * x).take(10) {
    println!("{}", elem);
}

GenIterReturn and gen_iter_return!

GenIterReturn can be converted from a Generator<()>, &mut GenIterReturn<G> can be used as iterator. The return value of the generator can be got after the iterator is exhausted.

gen_iter_return! helps to create a GenIterReturn.

#![feature(generators)]

use gen_iter::gen_iter_return;

let mut g = gen_iter_return!({
    yield 1;
    yield 2;
    return "done";
});
 
for y in &mut g {
    println!("yield {}", y);
}
println!("generator is_done={}", g.is_done()); // true
println!("generator returns {}", g.return_or_self().ok().unwrap()); // "done"

Macros

gen_iter

macro to simplify iterator - via - generator construction

gen_iter_return

macro to simplify iterator - via - generator with return value construction

Structs

GenIter

an iterator that holds an internal generator representing the iteration state

GenIterReturn

GenIterReturn<G> holds a generator G or the return value of G, &mut GenIterReturn<G> acts as an iterator.