partway towards commands

I got very confused and started mucking about with "spawn" when in fact all I needed was the "inline" extension type in orcx that allows the interpreter to expose custom constants.

orchid-host/src/ctx.rs

@@ -1,6 +1,7 @@
 use std::cell::RefCell;
 use std::num::{NonZero, NonZeroU16};
 use std::rc::{Rc, Weak};
+use std::time::Duration;
 use std::{fmt, ops};
 
 use futures::future::LocalBoxFuture;
@@ -14,12 +15,21 @@ use crate::system::{System, WeakSystem};
 use crate::tree::WeakRoot;
 
 pub trait JoinHandle {
+	/// It is guaranteed that the future will never be polled after this is called
 	fn abort(&self);
+	/// take the future out of the task. If the return value
+	/// is dropped, the spawned future is also dropped
 	fn join(self: Box<Self>) -> LocalBoxFuture<'static, ()>;
 }
 
 pub trait Spawner {
-	fn spawn_obj(&self, fut: LocalBoxFuture<'static, ()>) -> Box<dyn JoinHandle>;
+	/// Spawn a future off-task, but in the same thread. If all objects associated
+	/// with the owning [Ctx] are dropped (eg. expressions, extensions, systems)
+	/// and no extensions create permanent ref loops, then all tasks will
+	/// eventually settle, therefore the implementor of this interface should not
+	/// exit while there are pending tasks to allow external communication
+	/// channels to cleanly shut down.
+	fn spawn_obj(&self, delay: Duration, fut: LocalBoxFuture<'static, ()>) -> Box<dyn JoinHandle>;
 }
 
 pub struct CtxData {
@@ -58,12 +68,16 @@ impl Ctx {
 	}
 	/// Spawn a parallel future that you can join at any later time.
 	///
-	/// Don't use this for async Drop, use [orchid_base::stash::stash] instead.
+	/// Don't use this for async Drop, use [orchid_base::stash] instead.
 	/// If you use this for an actor object, make sure to actually join the
 	/// handle.
 	#[must_use]
-	pub fn spawn(&self, fut: impl Future<Output = ()> + 'static) -> Box<dyn JoinHandle> {
-		self.spawner.spawn_obj(Box::pin(fut))
+	pub fn spawn(
+		&self,
+		delay: Duration,
+		fut: impl Future<Output = ()> + 'static,
+	) -> Box<dyn JoinHandle> {
+		self.spawner.spawn_obj(delay, Box::pin(fut))
 	}
 	#[must_use]
 	pub(crate) async fn system_inst(&self, id: api::SysId) -> Option<System> {