From fc2ff685f4cc9b3e7afc3325026d05444a752b19 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Julien=20Valverd=C3=A9?= <julien.valverde@mailo.com>
Date: Thu, 16 Jul 2026 23:25:34 +0200
Subject: [PATCH] Add zipLatestAll

---
 packages/effect-lens-next/src/View.ts    | 32 ++++++++++++++++++------
 packages/effect-lens/src/Subscribable.ts | 16 ++++++++++++
 2 files changed, 40 insertions(+), 8 deletions(-)

diff --git a/packages/effect-lens-next/src/View.ts b/packages/effect-lens-next/src/View.ts
index 27cd1d8..bc0160d 100644
--- a/packages/effect-lens-next/src/View.ts
+++ b/packages/effect-lens-next/src/View.ts
@@ -99,6 +99,30 @@ export const mapOptionEffect: {
     onNone: () => Effect.succeed(Option.none()),
 })))
 
+/** Converts typed failures from both channels into `Result` values. */
+export const result = <A, E, R>(
+    self: View<A, E, R>,
+): View<Result.Result<A, E>, never, R> => make({
+    get get() { return Effect.result(self.get) },
+    get changes() { return Stream.result(self.changes) },
+})
+
+/**
+ * Combines the current values and streams of changes from multiple `View` values.
+ */
+export const zipLatestAll = <const T extends readonly View<any, any, any>[]>(
+    ...elements: T
+): View<
+    [T[number]] extends [never]
+        ? never
+        : { [K in keyof T]: T[K] extends View<infer A, infer _E, infer _R> ? A : never },
+    [T[number]] extends [never] ? never : T[number] extends View<infer _A, infer E, infer _R> ? E : never,
+    [T[number]] extends [never] ? never : T[number] extends View<infer _A, infer _E, infer R> ? R : never
+> => make({
+    get: Effect.all(elements.map(view => view.get)),
+    changes: Stream.zipLatestAll(...elements.map(view => view.changes)),
+}) as any
+
 
 /** Maps errors from both the current value and the stream of changes. */
 export const mapError: {
@@ -192,14 +216,6 @@ export const retry: {
     get changes() { return Stream.retry(self.changes, policy) },
 }))
 
-/** Converts typed failures from both channels into `Result` values. */
-export const result = <A, E, R>(
-    self: View<A, E, R>,
-): View<Result.Result<A, E>, never, R> => make({
-    get get() { return Effect.result(self.get) },
-    get changes() { return Stream.result(self.changes) },
-})
-
 
 /** Narrows the focus to a field of an object. */
 export const focusObjectOn: {
diff --git a/packages/effect-lens/src/Subscribable.ts b/packages/effect-lens/src/Subscribable.ts
index c2ac183..9e6d107 100644
--- a/packages/effect-lens/src/Subscribable.ts
+++ b/packages/effect-lens/src/Subscribable.ts
@@ -40,6 +40,22 @@ export const mapOptionEffect: {
     onNone: () => Effect.succeed(Option.none()),
 })))
 
+/**
+ * Combines the current values and streams of changes from multiple `Subscribable` values.
+ */
+export const zipLatestAll = <const T extends readonly Subscribable.Subscribable<any, any, any>[]>(
+    ...elements: T
+): Subscribable.Subscribable<
+    [T[number]] extends [never]
+        ? never
+        : { [K in keyof T]: T[K] extends Subscribable.Subscribable<infer A, infer _E, infer _R> ? A : never },
+    [T[number]] extends [never] ? never : T[number] extends Subscribable.Subscribable<infer _A, infer E, infer _R> ? E : never,
+    [T[number]] extends [never] ? never : T[number] extends Subscribable.Subscribable<infer _A, infer _E, infer R> ? R : never
+> => Subscribable.make({
+    get: Effect.all(elements.map(view => view.get)),
+    changes: Stream.zipLatestAll(...elements.map(view => view.changes)),
+}) as any
+
 
 /**
  * Maps errors from both the current value and the stream of changes.