Remove children from AccountUpdate: RFC and Implementation

CHANGELOG.md

@@ -17,6 +17,14 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ## [Unreleased](https://github.com/o1-labs/o1js/compare/834a44002...HEAD)
 
+### Breaking changes
+
+- Remove `AccountUpdate.children` and `AccountUpdate.parent` properties https://github.com/o1-labs/o1js/pull/1402
+  - Also removes the optional `AccountUpdatesLayout` argument to `approve()`
+  - Adds `AccountUpdateTree` and `AccountUpdateForest`, new classes that represent a layout of account updates explicitly
+  - Both of the new types are now accepted as inputs to `approve()`
+  - `accountUpdate.extractTree()` to obtain the tree associated with an account update in the current transaction context.
+
 ### Added
 
 - `MerkleList<T>` to enable provable operations on a dynamically-sized list https://github.com/o1-labs/o1js/pull/1398

src/examples/zkapps/token_with_proofs.ts

@@ -56,10 +56,8 @@ class TokenContract extends SmartContract {
     receiverAddress: PublicKey,
     callback: Experimental.Callback<any>
   ) {
-    let senderAccountUpdate = this.approve(
-      callback,
-      AccountUpdate.Layout.AnyChildren
-    );
+    // TODO use token contract methods for approve
+    let senderAccountUpdate = this.approve(callback) as AccountUpdate;
     let amount = UInt64.from(1_000);
     let negativeAmount = Int64.fromObject(
       senderAccountUpdate.body.balanceChange

src/index.ts

@@ -76,6 +76,7 @@ export {
   ZkappPublicInput,
   TransactionVersion,
   AccountUpdateForest,
+  AccountUpdateTree,
 } from './lib/account_update.js';
 
 export { TokenAccountUpdateIterator } from './lib/mina/token/forest-iterator.js';