Trait WidebandExt 

pub trait WidebandExt<Item>
where
    Self: Stream<Item = Item> + Send + Sized,
{
    // Required methods
    fn widen_filter_map<F, Fut, U, N>(
        self,
        n: N,
        f: F,
    ) -> impl Stream<Item = U> + Send
       where N: Into<Option<usize>>,
             F: Fn(Item) -> Fut + Send,
             Fut: Future<Output = Option<U>> + Send,
             U: Send;
    fn widen_then<F, Fut, U, N>(
        self,
        n: N,
        f: F,
    ) -> impl Stream<Item = U> + Send
       where N: Into<Option<usize>>,
             F: Fn(Item) -> Fut + Send,
             Fut: Future<Output = U> + Send,
             U: Send;

    // Provided methods
    fn wide_filter_map<F, Fut, U>(self, f: F) -> impl Stream<Item = U> + Send
       where F: Fn(Item) -> Fut + Send,
             Fut: Future<Output = Option<U>> + Send,
             U: Send { ... }
    fn wide_then<F, Fut, U>(self, f: F) -> impl Stream<Item = U> + Send
       where F: Fn(Item) -> Fut + Send,
             Fut: Future<Output = U> + Send,
             U: Send { ... }
}

Adds bounded concurrent transformations that preserve stream order.

Multiple item futures may run ahead of downstream demand. Completed outputs are held until every earlier input has produced its output.

Required Methods

fn widen_filter_map<F, Fut, U, N>( self, n: N, f: F, ) -> impl Stream<Item = U> + Send

where N: Into<Option<usize>>, F: Fn(Item) -> Fut + Send, Fut: Future<Output = Option<U>> + Send, U: Send,

Maps and filters items concurrently with an explicit width.

n limits in-flight item futures, while None selects the automatic width; an explicit zero cannot make progress. Present outputs retain source order and absent outputs are omitted.

fn widen_then<F, Fut, U, N>(self, n: N, f: F) -> impl Stream<Item = U> + Send

where N: Into<Option<usize>>, F: Fn(Item) -> Fut + Send, Fut: Future<Output = U> + Send, U: Send,

Maps items concurrently with an explicit width while preserving order.

n limits in-flight item futures, while None selects the automatic width; an explicit zero cannot make progress. Item futures may run ahead, but outputs retain source order.

Provided Methods

fn wide_filter_map<F, Fut, U>(self, f: F) -> impl Stream<Item = U> + Send

where F: Fn(Item) -> Fut + Send, Fut: Future<Output = Option<U>> + Send, U: Send,

Maps and filters items concurrently with the automatic width.

Present outputs retain source order even when their futures complete out of order. Absent outputs are omitted.

fn wide_then<F, Fut, U>(self, f: F) -> impl Stream<Item = U> + Send

where F: Fn(Item) -> Fut + Send, Fut: Future<Output = U> + Send, U: Send,

Maps items concurrently with the automatic width while preserving order.

Item futures may run ahead of downstream demand. Completed outputs wait for every earlier input before being yielded.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors

impl<Item, S> WidebandExt<Item> for S

where S: Stream<Item = Item> + Send + Sized,