57 lines
1.4 KiB
Rust
57 lines
1.4 KiB
Rust
//! Synchronous combinator extensions to futures::TryStream
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use futures::{TryFuture, TryStream, TryStreamExt};
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use super::automatic_width;
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use crate::Result;
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/// Concurrency extensions to augment futures::TryStreamExt. wide_ combinators
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/// produce in-order results
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pub trait TryWidebandExt<T, E>
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where
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Self: TryStream<Ok = T, Error = E, Item = Result<T, E>> + Send + Sized,
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{
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fn widen_and_then<U, F, Fut, N>(
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self,
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n: N,
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f: F,
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) -> impl TryStream<Ok = U, Error = E, Item = Result<U, E>> + Send
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where
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N: Into<Option<usize>>,
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F: Fn(Self::Ok) -> Fut + Send,
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Fut: TryFuture<Ok = U, Error = E, Output = Result<U, E>> + Send,
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U: Send;
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fn wide_and_then<U, F, Fut>(
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self,
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f: F,
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) -> impl TryStream<Ok = U, Error = E, Item = Result<U, E>> + Send
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where
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F: Fn(Self::Ok) -> Fut + Send,
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Fut: TryFuture<Ok = U, Error = E, Output = Result<U, E>> + Send,
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U: Send,
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{
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self.widen_and_then(None, f)
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}
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}
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impl<T, E, S> TryWidebandExt<T, E> for S
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where
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S: TryStream<Ok = T, Error = E, Item = Result<T, E>> + Send + Sized,
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E: Send,
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{
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fn widen_and_then<U, F, Fut, N>(
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self,
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n: N,
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f: F,
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) -> impl TryStream<Ok = U, Error = E, Item = Result<U, E>> + Send
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where
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N: Into<Option<usize>>,
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F: Fn(Self::Ok) -> Fut + Send,
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Fut: TryFuture<Ok = U, Error = E, Output = Result<U, E>> + Send,
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U: Send,
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{
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self.map_ok(f)
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.try_buffered(n.into().unwrap_or_else(automatic_width))
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}
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}
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