Struct Gen

pub struct Gen<Y, R, F: Future> { /* private fields */ }

This is a generator which stores its state on the heap.

See the module-level docs for examples.

Implementations

impl<Y, R, F: Future> Gen<Y, R, F>

pub fn new(producer: impl FnOnce(Co<Y, R>) -> F) -> Self

Creates a new generator from a function.

The function accepts a Co object, and returns a future. Every time the generator is resumed, the future is polled. Each time the future is polled, it should do one of two things:

• Call co.yield_(), and then return Poll::Pending.
• Drop the Co, and then return Poll::Ready.

Typically this exchange will happen in the context of an async fn.

See the module-level docs for examples.

pub fn resume_with(&mut self, arg: R) -> GeneratorState<Y, F::Output>

Resumes execution of the generator.

arg is the resume argument. If the generator was previously paused by awaiting a future returned from co.yield(), that future will complete, and return arg.

If the generator yields a value, Yielded is returned. Otherwise, Completed is returned.

See the module-level docs for examples.

impl<Y, F: Future> Gen<Y, (), F>

pub fn resume(&mut self) -> GeneratorState<Y, F::Output>

Resumes execution of the generator.

If the generator yields a value, Yielded is returned. Otherwise, Completed is returned.

See the module-level docs for examples.

pub fn async_resume( &mut self, ) -> impl Future<Output = GeneratorState<Y, F::Output>> + '_

Resumes execution of the generator.

If the generator pauses without yielding, Poll::Pending is returned. If the generator yields a value, Poll::Ready(Yielded) is returned. Otherwise, Poll::Ready(Completed) is returned.

See the module-level docs for examples.

Trait Implementations

impl<Y, R, F: Future> Coroutine for Gen<Y, R, F>

type Yield = Y

The type of value this generator yields.

type Resume = R

The type of value this generator accepts as a resume argument.

type Return = <F as Future>::Output

The type of value this generator returns upon completion.

fn resume_with( self: Pin<&mut Self>, arg: R, ) -> GeneratorState<Self::Yield, Self::Return>

Resumes the execution of this generator.

impl<Y, F: Future<Output = ()>> IntoIterator for Gen<Y, (), F>

type Item = Y

The type of the elements being iterated over.

type IntoIter = IntoIter<Y, F>

Which kind of iterator are we turning this into?

fn into_iter(self) -> Self::IntoIter

Creates an iterator from a value.