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use crate::{
bind, intercept_input, map, map_input, map_output, receive, recieve_until, result, right,
run_step, send, subroutine, suspend, tuple, Coroutine, StepResult,
};
pub enum Select<A, B, C> {
Left(A),
Right(B),
Both(C),
}
pub enum DispatchResult<'a, IA, IB, OA, OB, A, B> {
Left {
value: A,
remaining: Coroutine<'a, IB, OB, B>,
},
Right {
value: B,
remaining: Coroutine<'a, IA, OA, A>,
},
}
type DispatchRoutine<'a, IA, IB, IAB, OA, OB, A, B> = Coroutine<
'a,
Select<IA, IB, IAB>,
UnicastSelect<OA, OB>,
DispatchResult<'a, IA, IB, OA, OB, A, B>,
>;
pub fn dispatch<'a, IA, IB, IAB, OA, OB, A, B>(
first: Coroutine<'a, IA, OA, A>,
second: Coroutine<'a, IB, OB, B>,
) -> DispatchRoutine<'a, IA, IB, IAB, OA, OB, A, B>
where
IAB: Into<IA> + Into<IB> + Clone,
OA: Send,
OB: Send,
A: Send,
B: Send,
{
let s1 = run_step(first);
let s2 = run_step(second);
match (s1, s2) {
(StepResult::Done(value), StepResult::Done(b)) => {
let ret = DispatchResult::Left {
value,
remaining: result(b),
};
result(ret)
}
(StepResult::Done(value), StepResult::Yield { output, next }) => {
let remaining = *next;
let race = DispatchResult::Left { value, remaining };
right(send(UnicastSelect::Right(output)), result(race))
}
(StepResult::Done(value), StepResult::Next(next)) => {
let remaining = suspend(next);
result(DispatchResult::Left { value, remaining })
}
(StepResult::Yield { output, next }, StepResult::Done(value)) => {
let remaining = *next;
let race = DispatchResult::Right { value, remaining };
right(send(UnicastSelect::Left(output)), result(race))
}
(
StepResult::Yield {
output: a,
next: na,
},
StepResult::Yield {
output: b,
next: nb,
},
) => {
let send = tuple(send(UnicastSelect::Left(a)), send(UnicastSelect::Right(b)));
let next = dispatch(*na, *nb);
right(send, next)
}
(StepResult::Yield { output, next: a }, StepResult::Next(b)) => {
let send = send(UnicastSelect::Left(output));
let next = dispatch(*a, suspend(b));
right(send, next)
}
(StepResult::Next(a), StepResult::Done(value)) => {
let remaining = suspend(a);
let race = DispatchResult::Right { value, remaining };
result(race)
}
(StepResult::Next(a), StepResult::Yield { output, next }) => {
let send = send(UnicastSelect::Right(output));
let a = suspend(a);
let b = *next;
let next = dispatch(a, b);
right(send, next)
}
(StepResult::Next(a), StepResult::Next(b)) => {
let on_input = |input: Select<IA, IB, IAB>| match input {
Select::Left(ia) => {
let a = a(ia);
dispatch(a, suspend(b))
}
Select::Right(ib) => {
let b = b(ib);
dispatch(suspend(a), b)
}
Select::Both(iab) => {
let ia = iab.clone().into();
let ib = iab.into();
let a = a(ia);
let b = b(ib);
dispatch(a, b)
}
};
bind(receive(), on_input)
}
}
}
pub type BroadcastRoutine<'a, I, OA, OB, A, B> =
Coroutine<'a, I, UnicastSelect<OA, OB>, DispatchResult<'a, I, I, OA, OB, A, B>>;
pub fn broadcast<'a, I, OA, OB, A, B>(
first: Coroutine<'a, I, OA, A>,
second: Coroutine<'a, I, OB, B>,
) -> BroadcastRoutine<'a, I, OA, OB, A, B>
where
I: Clone,
A: Send,
B: Send,
OA: Send,
OB: Send,
{
fn both_selector<I>(input: I) -> Select<I, I, I> {
Select::Both(input)
}
map_input(dispatch(first, second), both_selector)
}
pub fn broadcast_until_finished<'a, I, O, A, B>(
first: Coroutine<'a, I, O, A>,
second: Coroutine<'a, I, O, B>,
) -> Coroutine<'a, I, O, (A, B)>
where
I: Clone,
A: Send,
B: Send,
O: Send,
{
let rr = broadcast(first, second);
let rr = map_output(rr, |input| match input {
UnicastSelect::Left(a) => a,
UnicastSelect::Right(a) => a,
});
let on_result = |res| match res {
DispatchResult::Left { value, remaining } => map(remaining, |b| (value, b)),
DispatchResult::Right { value, remaining } => map(remaining, |a| (a, value)),
};
bind(rr, on_result)
}
pub enum UnicastSelect<A, B> {
Left(A),
Right(B),
}
pub fn unicast<'a, IA, IB, OA, OB, A, B>(
first: Coroutine<'a, IA, OA, A>,
second: Coroutine<'a, IB, OB, B>,
) -> Coroutine<
'a,
UnicastSelect<IA, IB>,
UnicastSelect<OA, OB>,
DispatchResult<'a, IA, IB, OA, OB, A, B>,
>
where
OA: Send,
OB: Send,
A: Send,
B: Send,
{
#[derive(Clone)]
enum Never {}
struct Wrapped<T>(T);
impl<T> From<Never> for Wrapped<T> {
fn from(_: Never) -> Self {
unreachable!("This should never be called")
}
}
let selector_ = move |input| -> Select<Wrapped<IA>, Wrapped<IB>, Never> {
match input {
UnicastSelect::Left(l) => Select::Left(Wrapped(l)),
UnicastSelect::Right(r) => Select::Right(Wrapped(r)),
}
};
let extract = |dr| match dr {
DispatchResult::Left { value, remaining } => {
let remaining = intercept_input(remaining, |input| result(Wrapped(input)));
DispatchResult::Left { value, remaining }
}
DispatchResult::Right { value, remaining } => {
let remaining = intercept_input(remaining, |input| result(Wrapped(input)));
DispatchResult::Right { value, remaining }
}
};
let first = intercept_input(first, |input: Wrapped<IA>| result(input.0));
let second = intercept_input(second, |input: Wrapped<IB>| result(input.0));
let both = map_input(dispatch(first, second), selector_);
map(both, extract)
}
pub fn unicast_until_finished<'a, IA, IB, O, A, B>(
first: Coroutine<'a, IA, O, A>,
second: Coroutine<'a, IB, O, B>,
) -> Coroutine<'a, UnicastSelect<IA, IB>, O, (A, B)>
where
O: Send,
A: Send,
B: Send,
{
let is_ib = move |input| match input {
UnicastSelect::Left(_) => result(None),
UnicastSelect::Right(b) => result(Some(b)),
};
let is_ia = move |input| match input {
UnicastSelect::Left(a) => result(Some(a)),
UnicastSelect::Right(_) => result(None),
};
let on_ib_input = move || recieve_until(is_ib);
let on_ia_input = move || recieve_until(is_ia);
let on_result = move |r| match r {
DispatchResult::Left { value, remaining } => {
let remaining = subroutine(on_ib_input, send, remaining);
map(remaining, |b| (value, b))
}
DispatchResult::Right { value, remaining } => {
let remaining = subroutine(on_ia_input, send, remaining);
map(remaining, |a| (a, value))
}
};
let ur = unicast(first, second);
let ur = map_output(ur, |o| match o {
UnicastSelect::Left(o) => o,
UnicastSelect::Right(o) => o,
});
bind(ur, on_result)
}