Types issues #253
Description
Hello
I am working on a small project to create a backend framework to handle events (microservices)
I am trying to implement the pipe to handle the events but I keep getting errors when calling subscribe()
Generally I dont get why is the implementation working this way.
- Why dont extend
Stream? - Why not return a unified definition of
Observable? Each OP returns a different defenition therefore creating a mess when trying to read errors (see below)
For reference check rxdart. They started with their own definition then went back to create operation extension on Stream from dart to solve all those issues, also each Op returns Stream and not MapOp, FilterOp etc ...
The code:
Simple version
from_future_result(ready(Ok("")), threads_scheduler)
.flat_map(|_| from_future_result(ready(Ok("")), threads_scheduler.clone()))
.on_error(|error| {})
.subscribe(|e| {}) // error hereFull version
#[derive(Clone)]
pub struct EventSource<Context, Event, Error>
where
Context: IntoBody + Sized + Send + Sync + 'static,
Event: IntoBody + Sized + Send + Sync + 'static,
Error: IntoBody + Sized + Send + Sync + 'static,
{
pub tx: Subject<'static, (Context, Event), Error>,
pub rx: Subject<'static, (Context, Event), Error>,
}
pub type EventHandler<Context, Event, Error> =
fn((Context, Event)) -> Pin<Box<dyn Future<Output = Result<(), Error>>>>;
pub type CreateSource<Context, Event, Error> =
fn() -> Pin<Box<dyn Future<Output = Result<EventSource<Context, Event, Error>, Error>>>>;
pub fn start_service<Context, Event, Error>(
source: CreateSource<Context, Event, Error>,
handler: EventHandler<Context, Event, Error>,
) -> Box<dyn Subscription>
where
Context: IntoBody + Sized + Sync + Send,
Event: IntoBody + Sized + Sync + Send,
Error: IntoBody + Sized + Sync + Send,
{
let threads_scheduler = futures::executor::ThreadPool::new().unwrap();
Box::new(
from_future_result(source(), threads_scheduler.clone())
.flat_map_threads(|source| source.rx)
.flat_map_threads(|event| from_future_result(handler(event), threads_scheduler.clone()))
.on_error(|error| {})
.subscribe(|result| {}), // issue is here
)
}Full error:
Details
the method `subscribe` exists for struct `OnErrorOp<MergeAllOpThreads<MapOp<MergeAllOpThreads<MapOp<..., ..., ...>, ...>, ..., ...>, ...>, ..., ...>`, but its trait bounds were not satisfied [E0599] Note: the full type name has been written to '/ Users/ shovelmn12/ Projects/ poc_server/ target/ debug/ deps/ poc_server-b47a2d7829a631fd. long-type-1706698521457854592.txt' Note: consider using `--verbose` to print the full type name to the console Note: the following trait bounds were not satisfied: `rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::Observable<_, std::convert::Infallible, rxrust::observable::ObserverItem<_>>` which is required by `rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::ObservableItem<_, _>` `&rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::Observable<_, std::convert::Infallible, rxrust::observable::ObserverItem<_>>` which is required by `&rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::ObservableItem<_, _>` `&mut rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::Observable<_, std::convert::Infallible, rxrust::observable::ObserverItem<_>>` which is required by `&mut rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::ObservableItem<_, _>`
the method `subscribe` exists for struct `OnErrorOp<MergeAllOpThreads<MapOp<MergeAllOpThreads<MapOp<..., ..., ...>, ...>, ..., ...>, ...>, ..., ...>`, but its trait bounds were not satisfied [E0599] Note: the full type name has been written to '/ Users/ shovelmn12/ Projects/ poc_server/ target/ debug/ deps/ poc_server-deb9ac863f34f807.long-type-7867709162962570806.txt' Note: consider using `--verbose` to print the full type name to the console Note: the following trait bounds were not satisfied: `rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::Observable<_, std::convert::Infallible, rxrust::observable::ObserverItem<_>>` which is required by `rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::ObservableItem<_, _>` `&rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::Observable<_, std::convert::Infallible, rxrust::observable::ObserverItem<_>>` which is required by `&rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::ObservableItem<_, _>` `&mut rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::Observable<_, std::convert::Infallible, rxrust::observable::ObserverItem<_>>` which is required by `&mut rxrust::ops::on_error::OnErrorOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::ops::merge_all::MergeAllOpThreads<rxrust::ops::map::MapOp<rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<EventSource<Context, Event, Error>, Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>, {closure@src/ main. rs:54:31: 54:39}, EventSource<Context, Event, Error>>, rxrust::subject::Subject<'static, (Context, Event), Error>>, {closure@src/ main. rs:55:31: 55:38}, (Context, Event)>, rxrust::observable::from_future::FutureResultObservable<std::pin::Pin<std::boxed::Box<dyn futures::Future<Output = std::result::Result<(), Error>>>>, rxrust::scheduler::FuturesThreadPoolScheduler>>, {closure@src/ main. rs:56:23: 56:30}, Error>: rxrust::observable::ObservableItem<_, _>`
FYI: not a rust expert, just honestly trying to understand :)