Added support for defining macros in Rust within the macro system

Also fixed a lot of bugs

orchid-host/src/extension.rs

@@ -28,6 +28,7 @@ use crate::api;
 use crate::atom::AtomHand;
 use crate::ctx::Ctx;
 use crate::dealias::{ChildError, ChildErrorKind, walk};
+use crate::expr::ExprKind;
 use crate::expr_store::ExprStore;
 use crate::system::SystemCtor;
 use crate::tree::MemberKind;
@@ -56,6 +57,7 @@ impl Drop for ExtensionData {
 		let mut exiting_snd = self.exiting_snd.clone();
 		(self.ctx.spawn)(Box::pin(async move {
 			reqnot.notify(api::HostExtNotif::Exit).await;
+
 			exiting_snd.send(()).await.unwrap()
 		}))
 	}
@@ -247,6 +249,13 @@ impl Extension {
 										let unit = atom.print(&FmtCtxImpl { i: &this.ctx().i }).await;
 										hand.handle(eap, &unit.to_api()).await
 									},
+									api::ExtHostReq::CreateAtom(ref create @ api::CreateAtom(ref atom, target)) => {
+										let atom = AtomHand::from_api(atom, Pos::None, &mut ctx.clone()).await;
+										let target = ctx.system_inst(target).await.expect("Invalid recipient for atom");
+										let expr = ExprKind::Atom(atom).at(Pos::None);
+										target.ext().exprs().give_expr(expr.clone());
+										hand.handle(create, &expr.id()).await
+									},
 								}
 							})
 						}