base and extension fully compiles, host in good shape

orchid-host/src/ctx.rs

@@ -0,0 +1,46 @@
+use std::cell::RefCell;
+use std::num::NonZeroU16;
+use std::rc::Rc;
+use std::{fmt, ops};
+
+use async_std::sync::RwLock;
+use futures::task::LocalSpawn;
+use hashbrown::HashMap;
+use orchid_api::SysId;
+use orchid_base::interner::Interner;
+
+use crate::api;
+use crate::atom::WeakAtomHand;
+use crate::system::{System, WeakSystem};
+
+pub struct CtxData {
+	pub i: Rc<Interner>,
+	pub spawn: Rc<dyn LocalSpawn>,
+	pub systems: RwLock<HashMap<api::SysId, WeakSystem>>,
+	pub system_id: RefCell<NonZeroU16>,
+	pub owned_atoms: RwLock<HashMap<api::AtomId, WeakAtomHand>>,
+}
+#[derive(Clone)]
+pub struct Ctx(Rc<CtxData>);
+impl ops::Deref for Ctx {
+	type Target = CtxData;
+	fn deref(&self) -> &Self::Target { &*self.0 }
+}
+impl Ctx {
+	pub(crate) async fn system_inst(&self, id: api::SysId) -> Option<System> {
+		self.systems.read().await.get(&id).and_then(WeakSystem::upgrade)
+	}
+	pub(crate) fn next_sys_id(&self) -> api::SysId {
+		let mut g = self.system_id.borrow_mut();
+		*g = g.checked_add(1).unwrap_or(NonZeroU16::new(1).unwrap());
+		SysId(*g)
+	}
+}
+impl fmt::Debug for Ctx {
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		f.debug_struct("Ctx")
+			.field("i", &self.i)
+			.field("system_id", &self.system_id)
+			.finish_non_exhaustive()
+	}
+}