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Remove poll*with_context functions #37

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Merged
merged 1 commit into from
May 2, 2020
Merged

Remove poll*with_context functions #37

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32 changes: 22 additions & 10 deletions futures-async-stream-macro/src/visitor.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -106,9 +106,9 @@ impl Visitor {
}
Stream | TryStream => {
quote! {
match unsafe { ::futures_async_stream::stream::poll_next_with_context(
match unsafe { ::futures_async_stream::stream::Stream::poll_next(
::futures_async_stream::reexport::pin::Pin::as_mut(&mut __pinned),
__task_context,
::futures_async_stream::future::get_context(__task_context),
) } {
::futures_async_stream::reexport::task::Poll::Ready(
::futures_async_stream::reexport::option::Option::Some(e),
Expand Down Expand Up @@ -191,19 +191,31 @@ impl Visitor {
return;
}

// Desugar `<base>.await` into:
//
// {
// let mut __pinned = <base>;
// loop {
// if let Poll::Ready(result) = unsafe { Future::poll(
// Pin::new_unchecked(&mut __pinned),
// get_context(__task_context),
// ) } {
// break result;
// }
// __task_context = yield Poll::Pending;
// }
// }
if let Expr::Await(ExprAwait { base, await_token, .. }) = expr {
*expr = syn::parse2(quote_spanned! { await_token.span() => {
let mut __pinned = #base;
loop {
if let ::futures_async_stream::reexport::task::Poll::Ready(x) =
unsafe { ::futures_async_stream::future::poll_with_context(
::futures_async_stream::reexport::pin::Pin::new_unchecked(&mut __pinned),
__task_context,
)}
{
break x;
if let ::futures_async_stream::reexport::task::Poll::Ready(result) =
unsafe { ::futures_async_stream::future::Future::poll(
::futures_async_stream::reexport::pin::Pin::new_unchecked(&mut __pinned),
::futures_async_stream::future::get_context(__task_context),
) } {
break result;
}

__task_context = yield ::futures_async_stream::reexport::task::Poll::Pending;
}
}})
Expand Down
26 changes: 8 additions & 18 deletions src/lib.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -234,14 +234,16 @@ pub use futures_async_stream_macro::async_try_stream_block;
#[doc(hidden)]
pub mod future {
use core::{
future::Future,
ops::{Generator, GeneratorState},
pin::Pin,
ptr::NonNull,
task::{Context, Poll},
};
use pin_project::pin_project;

#[doc(hidden)]
pub use core::future::Future;

/// This type is needed because:
///
/// a) Generators cannot implement `for<'a, 'b> Generator<&'a mut Context<'b>>`, so we need to pass
Expand Down Expand Up @@ -293,11 +295,8 @@ pub mod future {
}

#[doc(hidden)]
pub unsafe fn poll_with_context<F>(f: Pin<&mut F>, mut cx: ResumeTy) -> Poll<F::Output>
where
F: Future,
{
F::poll(f, cx.0.as_mut())
pub unsafe fn get_context<'a, 'b>(cx: ResumeTy) -> &'a mut Context<'b> {
&mut *cx.0.as_ptr().cast()
}
}

Expand All @@ -312,11 +311,13 @@ pub mod stream {
ptr::NonNull,
task::{Context, Poll},
};
use futures_core::stream::Stream;
use pin_project::pin_project;

use super::future::ResumeTy;

#[doc(hidden)]
pub use futures_core::stream::Stream;

/// Wrap a generator in a stream.
///
/// This function returns a `GenStream` underneath, but hides it in `impl Trait` to give
Expand Down Expand Up @@ -352,17 +353,6 @@ pub mod stream {
}
}

#[doc(hidden)]
pub unsafe fn poll_next_with_context<S>(
s: Pin<&mut S>,
mut cx: ResumeTy,
) -> Poll<Option<S::Item>>
where
S: Stream,
{
S::poll_next(s, cx.0.as_mut())
}

// This is equivalent to the `futures::stream::StreamExt::next` method.
// But we want to make this crate dependency as small as possible, so we define our `next` function.
#[doc(hidden)]
Expand Down