Experimenting with request API

Signed-off-by: Michael X. Grey <mxgrey@intrinsic.ai>

Author: mxgrey

src/request.rs

@@ -17,10 +17,10 @@
 
 use crate::{
     OutputChain, UnusedTarget, InputBundle, StreamPack, Provider,
-    ModifiersUnset, AddOperation, Noop, IntoAsyncMap,
+    ModifiersUnset, AddOperation, Noop, IntoAsyncMap, Promise,
 };
 
-use bevy::prelude::Commands;
+use bevy::prelude::{Commands, Entity, Bundle};
 
 use std::future::Future;
 
@@ -119,6 +119,47 @@ async fn async_server<T: Future>(value: T) -> T::Output {
     value.await
 }
 
+pub struct Target<Response, Streams> {
+    session: Entity,
+    _ignore: std::marker::PhantomData<(Response, Streams)>
+}
+
+impl<Response, Streams> Target<Response, Streams> {
+    /// If the target is dropped, the request will not be cancelled.
+    pub fn detach(self) -> Target<Response, Streams> {
+
+    }
+
+    /// Take the data that comes out of the request.
+    #[must_use]
+    pub fn take(self) -> Recipient<Response, Streams> {
+
+    }
+
+    /// Pass the outcome of the request to another provider.
+    #[must_use]
+    pub fn then<P: Provider<Request = Response>>(
+        self,
+        provider: Provider,
+    ) -> Target<P::Response, P::Streams> {
+
+    }
+}
+
+impl<Response, Streams> Target<Response, Streams>
+where
+    Response: Bundle,
+{
+    pub fn store(self, target: Entity) {
+
+    }
+}
+
+pub struct Recipient<Response, Streams: StreamPack> {
+    pub response: Promise<Response>,
+    pub streams: Streams::Receiver,
+}
+
 #[cfg(test)]
 mod tests {
     use crate::{*, testing::*};

src/stream.rs

@@ -17,6 +17,8 @@
 
 use bevy::prelude::{Component, Bundle, Entity, Commands, World};
 
+use crossbeam::channel::Receiver;
+
 use crate::{
     InputSlot, Output, UnusedTarget, RedirectWorkflowStream, RedirectScopeStream,
     AddOperation, OperationRoster, OperationResult, OrBroken, ManageInput,
@@ -118,6 +120,7 @@ pub trait StreamPack: 'static + Send + Sync {
     type StreamStorageBundle: Bundle;
     type StreamInputPack;
     type StreamOutputPack;
+    type Receiver;
 
     fn spawn_scope_streams(scope: Entity, commands: &mut Commands) -> (
         Self::StreamStorageBundle,
@@ -140,6 +143,7 @@ impl<T: Stream> StreamPack for T {
     type StreamStorageBundle = StreamTargetStorage<Self>;
     type StreamInputPack = InputSlot<Self>;
     type StreamOutputPack = Output<Self>;
+    type Receiver = Receiver<Self>;
 
     fn spawn_scope_streams(scope: Entity, commands: &mut Commands) -> (
         Self::StreamStorageBundle,
@@ -168,6 +172,7 @@ impl StreamPack for () {
     type StreamStorageBundle = ();
     type StreamInputPack = ();
     type StreamOutputPack = ();
+    type Receiver = ();
 
     fn spawn_scope_streams(_: Entity, _: &mut Commands) -> (
         Self::StreamStorageBundle,
@@ -196,6 +201,7 @@ impl<T1: StreamPack> StreamPack for (T1,) {
     type StreamStorageBundle = T1::StreamStorageBundle;
     type StreamInputPack = T1::StreamInputPack;
     type StreamOutputPack = T1::StreamOutputPack;
+    type Receiver = T1::Receiver;
 
     fn spawn_scope_streams(scope: Entity, commands: &mut Commands) -> (
         Self::StreamStorageBundle,
@@ -224,6 +230,7 @@ impl<T1: StreamPack, T2: StreamPack> StreamPack for (T1, T2) {
     type StreamStorageBundle = (T1::StreamStorageBundle, T2::StreamStorageBundle);
     type StreamInputPack = (T1::StreamInputPack, T2::StreamInputPack);
     type StreamOutputPack = (T1::StreamOutputPack, T2::StreamOutputPack);
+    type Receiver = (T1::Receiver, T2::Receiver);
 
     fn spawn_scope_streams(scope: Entity, commands: &mut Commands) -> (
         Self::StreamStorageBundle,
@@ -258,6 +265,7 @@ impl<T1: StreamPack, T2: StreamPack, T3: StreamPack> StreamPack for (T1, T2, T3)
     type StreamStorageBundle = (T1::StreamStorageBundle, T2::StreamStorageBundle, T3::StreamStorageBundle);
     type StreamInputPack = (T1::StreamInputPack, T2::StreamInputPack, T3::StreamInputPack);
     type StreamOutputPack = (T1::StreamOutputPack, T2::StreamOutputPack, T3::StreamOutputPack);
+    type Receiver = (T1::Receiver, T2::Receiver, T3::Receiver);
 
     fn spawn_scope_streams(scope: Entity, commands: &mut Commands) -> (
         Self::StreamStorageBundle,