wip: merge in some code from the other branch

packages/core/src/arena.rs

@@ -9,9 +9,9 @@ use generational_arena::Arena;
 use crate::innerlude::*;
 
 #[derive(Clone)]
-pub struct ScopeArena(Rc<RefCell<ScopeArenaInner>>);
+pub struct ScopeArena(pub Rc<RefCell<ScopeArenaInner>>);
 
-struct ScopeArenaInner {
+pub struct ScopeArenaInner {
     pub(crate) arena: UnsafeCell<Arena<Scope>>,
     locks: HashMap<ScopeIdx, MutStatus>,
 }
@@ -61,6 +61,13 @@ impl ScopeArena {
         // todo!()
     }
 
+    pub fn try_remove(&mut self, id: ScopeIdx) -> Result<Scope> {
+        let inner = unsafe { &mut *self.0.borrow().arena.get() };
+        inner
+            .remove(id)
+            .ok_or_else(|| Error::FatalInternal("Scope not found"))
+    }
+
     unsafe fn inner_unchecked<'s>() -> &'s mut Arena<Scope> {
         todo!()
     }