wip: new approach at direct access to vdom

This commit starts the process of merging scope arena
with the diff machine to give the diffing algorithm mutable
access to components. React and Preact mutate the dom
as they diff it which makes their implementations simpler
and cleaner. The goal here is to give access of scopes to
the diffing machine which can mutate the underyling
representation during diffing.

packages/core/src/diff.rs

@@ -32,7 +32,7 @@
 //!
 //! More info on how to improve this diffing algorithm:
 //!  - https://hacks.mozilla.org/2019/03/fast-bump-allocated-virtual-doms-with-rust-and-wasm/
-use crate::innerlude::*;
+use crate::{arena::ScopeArena, innerlude::*};
 use bumpalo::Bump;
 use fxhash::{FxHashMap, FxHashSet};
 use generational_arena::Arena;
@@ -62,6 +62,7 @@ pub struct DiffMachine<'a> {
     pub change_list: EditMachine<'a>,
     pub diffed: FxHashSet<ScopeIdx>,
     pub lifecycle_events: VecDeque<LifeCycleEvent<'a>>,
+    pub vdom: ScopeArena,
 }
 pub enum LifeCycleEvent<'a> {
     Mount {
@@ -97,8 +98,9 @@ fn get_id() -> u32 {
 }
 
 impl<'a> DiffMachine<'a> {
-    pub fn new() -> Self {
+    pub fn new(vdom: ScopeArena) -> Self {
         Self {
+            vdom,
             create_diffs: true,
             lifecycle_events: VecDeque::new(),
             change_list: EditMachine::new(),