Add reducer API production warning

CHANGELOG.md

@@ -19,6 +19,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Added
 
+- A warning about the current reducer API limitations, as well as a mention of active work to mitigate them was added to doc comments and examples https://github.com/o1-labs/o1js/pull/1728
+
 - `ForeignField`-based representation of scalars via `ScalarField` https://github.com/o1-labs/o1js/pull/1705
 - Introduced new V2 methods for nullifier operations: `isUnusedV2()`, `assertUnusedV2()`, and `setUsedV2()` https://github.com/o1-labs/o1js/pull/1715
 

src/examples/zkapps/dex/dex-with-actions.ts

@@ -2,7 +2,11 @@
  * This DEX implementation differs from ./dex.ts in two ways:
  * - More minimal & realistic; stuff designed only for testing protocol features was removed
  * - Uses an async pattern with actions that lets users claim funds later and reduces account updates
- */
+ * 
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
 import {
   Account,
   AccountUpdate,

src/examples/zkapps/reducer/actions-as-merkle-list-iterator.ts

@@ -4,7 +4,11 @@
  *
  * This is mainly intended as an example for using `Iterator` and `MerkleList`, but it might also be useful as
  * a blueprint for processing actions in a custom and more explicit way.
- */
+ * 
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
 import {
   Field,
   Mina,

src/examples/zkapps/reducer/actions-as-merkle-list.ts

@@ -4,7 +4,11 @@
  *
  * This is mainly intended as an example for using `MerkleList`, but it might also be useful as
  * a blueprint for processing actions in a custom and more explicit way.
- */
+ * 
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
 import {
   Bool,
   Mina,

src/examples/zkapps/reducer/map.ts

@@ -22,6 +22,10 @@ In this example, the keys are public keys, and the values are arbitrary field el
 
 This utilizes the `Reducer` as an append online list of actions, which are then looked at to find the value corresponding to a specific key.
 
+Warning: The reducer API in o1js is currently not safe to use in production applications. The reduce() 
+method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+in progress to mitigate this limitation.
+
 
 ```ts 
 // js

src/examples/zkapps/reducer/reducer-composite.ts

@@ -1,3 +1,11 @@
+/**
+ * This example demonstrates a pattern to use actions for concurrent state updates. 
+ * 
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
+
 import {
   Field,
   state,

src/examples/zkapps/voting/demo.ts

@@ -1,5 +1,12 @@
-// used to do a dry run, without tests
-// ./run ./src/examples/zkapps/voting/demo.ts
+
+/*
+ * used to do a dry run, without tests
+ * ./run ./src/examples/zkapps/voting/demo.ts
+ * 
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
 
 import { Mina, AccountUpdate, PrivateKey, UInt64, Reducer, Bool } from 'o1js';
 import { VotingApp, VotingAppParams } from './factory.js';

src/examples/zkapps/voting/membership.ts

@@ -1,3 +1,8 @@
+/*
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
 import {
   Field,
   SmartContract,

src/examples/zkapps/voting/voting.ts

@@ -1,3 +1,8 @@
+/*
+ * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+ * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+ * in progress to mitigate this limitation.
+ */ 
 import {
   Field,
   SmartContract,

src/lib/mina/actions/reducer.ts

@@ -65,6 +65,9 @@ type ReducerReturn<Action> = {
    * );
    * ```
    *
+   * Warning: The reducer API in o1js is currently not safe to use in production applications. The `reduce()` 
+   * method breaks if more than the hard-coded number (default: 32) of actions are pending. Work is actively 
+   * in progress to mitigate this limitation.
    */
   reduce<State>(
     actions: MerkleList<MerkleList<Action>>,