Regenerate lockfile

This PR contains the following updates:

| Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [npm-check-updates](https://github.com/raineorshine/npm-check-updates) | [`^19.6.6` → `^21.0.0`](https://renovatebot.com/diffs/npm/npm-check-updates/19.6.6/21.0.3) | ![age](https://developer.mend.io/api/mc/badges/age/npm/npm-check-updates/21.0.3?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/npm/npm-check-updates/19.6.6/21.0.3?slim=true) |

---

### Release Notes

<details>
<summary>raineorshine/npm-check-updates (npm-check-updates)</summary>

### [`v21.0.3`](https://github.com/raineorshine/npm-check-updates/releases/tag/v21.0.3)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v21.0.2...v21.0.3)

#### What's Changed

- fix: chmod build/cli.js executable after vite build by [@&#8203;raineorshine](https://github.com/raineorshine) in [#&#8203;1678](https://github.com/raineorshine/npm-check-updates/pull/1678)
- fix: migrate from rc-config-loader to cosmiconfig for ESM config support (closes [#&#8203;1674](https://github.com/raineorshine/npm-check-updates/issues/1674)) by [@&#8203;onemen](https://github.com/onemen) in [#&#8203;1676](https://github.com/raineorshine/npm-check-updates/pull/1676)

**Full Changelog**: <https://github.com/raineorshine/npm-check-updates/compare/v21.0.2...v21.0.3>

### [`v21.0.2`](https://github.com/raineorshine/npm-check-updates/releases/tag/v21.0.2)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v21.0.1...v21.0.2)

#### What's Changed

- fix: skip intersects() for non-semver specs like catalog: in peer dep checks by [@&#8203;terminalchai](https://github.com/terminalchai) in [#&#8203;1675](https://github.com/raineorshine/npm-check-updates/pull/1675)

**Full Changelog**: <https://github.com/raineorshine/npm-check-updates/compare/v21.0.1...v21.0.2>

### [`v21.0.1`](https://github.com/raineorshine/npm-check-updates/releases/tag/v21.0.1)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v21.0.0...v21.0.1)

#### What's Changed

- fix: seeing catalog when inside workspaces by [@&#8203;Zamiell](https://github.com/Zamiell) in [#&#8203;1656](https://github.com/raineorshine/npm-check-updates/pull/1656)
- Bump [@&#8203;types/bun](https://github.com/types/bun) from 1.3.11 to 1.3.12 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1663](https://github.com/raineorshine/npm-check-updates/pull/1663)
- Bump globals from 17.4.0 to 17.5.0 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1664](https://github.com/raineorshine/npm-check-updates/pull/1664)
- Bump [@&#8203;typescript-eslint/parser](https://github.com/typescript-eslint/parser) from 8.58.1 to 8.58.2 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1665](https://github.com/raineorshine/npm-check-updates/pull/1665)
- Bump prettier from 3.8.1 to 3.8.2 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1667](https://github.com/raineorshine/npm-check-updates/pull/1667)
- Bump verdaccio from 6.4.0 to 6.5.0 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1669](https://github.com/raineorshine/npm-check-updates/pull/1669)
- Bump sinon from 21.0.3 to 21.1.2 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1668](https://github.com/raineorshine/npm-check-updates/pull/1668)
- Skip CI on PRs with no file changes by [@&#8203;Copilot](https://github.com/Copilot) in [#&#8203;1672](https://github.com/raineorshine/npm-check-updates/pull/1672)
- Bump [@&#8203;typescript-eslint/eslint-plugin](https://github.com/typescript-eslint/eslint-plugin) from 8.58.1 to 8.58.2 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1666](https://github.com/raineorshine/npm-check-updates/pull/1666)
- Fix wrong message when all packages are within cooldown window by [@&#8203;Copilot](https://github.com/Copilot) in [#&#8203;1671](https://github.com/raineorshine/npm-check-updates/pull/1671)

**Full Changelog**: <https://github.com/raineorshine/npm-check-updates/compare/v21.0.0...v21.0.1>

### [`v21.0.0`](https://github.com/raineorshine/npm-check-updates/blob/HEAD/CHANGELOG.md#2100---2026-04-14)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v20.0.2...v21.0.0)

##### ⚠️ Breaking Changes

This is a **major breaking change** with significant architectural updates.

##### ESM Migration & Module System

- **Pure ESM:** Converted to pure ESM with dual-build support (ESM/CJS) via Vite 8.
- **Import Syntax:** Programmatic usage now requires named imports or namespace imports.
  - **Old:** `import ncu from 'npm-check-updates'`
  - **New:** `import * as ncu from 'npm-check-updates'` or `import { run } from 'npm-check-updates'`
- **Node.js Requirements:** Now requires `^20.19.0 || ^22.12.0 || >=24.0.0`. This is required for native `require(esm)` support and the Rolldown engine.
- **npm Requirements:** Minimum version increased to `>=10.0.0`.

##### Configuration Files (`.ncurc.js`)

- Files named `.ncurc.js` that use `module.exports` will now fail in projects that are `"type": "module"`.
- **Fix:** Rename these files to `.ncurc.cjs` or convert them to use `export default`.

##### Dependency Updates (Pure ESM versions)

| Package            | Old Version | New Version |
| :----------------- | :---------- | :---------- |
| `camelcase`        | `^6.3.0`    | `^9.0.0`    |
| `chai`             | `^4.3.10`   | `^6.2.2`    |
| `chai-as-promised` | `^7.1.2`    | `^8.0.2`    |
| `find-up`          | `5.0.0`     | `8.0.0`     |
| `p-map`            | `^4.0.0`    | `^7.0.4`    |
| `untildify`        | `^4.0.0`    | `^6.0.0`    |

##### Tooling & Build Changes

- **Vite 8 Upgrade:** Migrated to Vite 8 with the new Rust-based **Rolldown** bundler (10-30x faster builds).
- **TypeScript 6.0:** Adopted latest type-system features and performance improvements.
- **Strip ANSI:** Replaced `strip-ansi` with Node.js built-in `util.stripVTControlCharacters`.
- **Test Runner:** Replaced `vite-node` with `tsx` for TypeScript support in ESM context.

***

##### Migration Guide

If you are upgrading to v21 from earlier versions:

##### 1. Environment Check

- Ensure you meet the new Node.js requirement: `^20.19.0 || ^22.12.0 || >=24.0.0`.
- Update npm to at least `10.0.0`.

##### 2. Update Configuration Files

If you have a `.ncurc.js` file:

- **Option A:** Rename it to `.ncurc.cjs`.
- **Option B:** Convert it to ESM:

  ```js
  import { defineConfig } from 'npm-check-updates'

  export default defineConfig({
    upgrade: true,
    filter: name => name.startsWith('@&#8203;myorg/'),
  })
  ```

##### 3. Update Programmatic Usage

If you import `npm-check-updates` in your scripts:

- **ESM:** Change `import ncu from ...` to `import * as ncu from 'npm-check-updates'`.
- **CommonJS:** Ensure you are destructuring the named exports or using the full object:

```js
const ncu = require('npm-check-updates')
// Use ncu.run(...)
```

***

##### Testing

Tests now use `tsx` for module loading. When running tests manually:

```sh
mocha --node-option import=tsx 'test/**/*.test.ts'
```

Or use the npm script:

```sh
npm test
```

##### Related Issues & PRs

[PR 1649](https://github.com/raineorshine/npm-check-updates/pull/1649)

***

### [`v20.0.2`](https://github.com/raineorshine/npm-check-updates/releases/tag/v20.0.2)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v20.0.1...v20.0.2)

#### What's Changed

- Show auto-detected cooldown source at normal log level; fix test isolation by [@&#8203;bayraak](https://github.com/bayraak) in [#&#8203;1662](https://github.com/raineorshine/npm-check-updates/pull/1662)

#### New Contributors

- [@&#8203;bayraak](https://github.com/bayraak) made their first contribution in [#&#8203;1662](https://github.com/raineorshine/npm-check-updates/pull/1662)

**Full Changelog**: <https://github.com/raineorshine/npm-check-updates/compare/v20.0.1...v20.0.2>

### [`v20.0.1`](https://github.com/raineorshine/npm-check-updates/releases/tag/v20.0.1)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v20.0.0...v20.0.1)

#### What's Changed

- Add CI workflow to verify build output is committed by [@&#8203;Copilot](https://github.com/Copilot) in [#&#8203;1645](https://github.com/raineorshine/npm-check-updates/pull/1645)
- Bump lodash-es from 4.17.23 to 4.18.1 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1647](https://github.com/raineorshine/npm-check-updates/pull/1647)
- Add Node v24 to test workflow by [@&#8203;Copilot](https://github.com/Copilot) in [#&#8203;1608](https://github.com/raineorshine/npm-check-updates/pull/1608)
- feat: remove pre-push git hook by [@&#8203;Zamiell](https://github.com/Zamiell) in [#&#8203;1658](https://github.com/raineorshine/npm-check-updates/pull/1658)
- feat: add verbose output when packages are skipped due to cooldown by [@&#8203;Copilot](https://github.com/Copilot) in [#&#8203;1659](https://github.com/raineorshine/npm-check-updates/pull/1659)

**Full Changelog**: <https://github.com/raineorshine/npm-check-updates/compare/v20.0.0...v20.0.1>

### [`v20.0.0`](https://github.com/raineorshine/npm-check-updates/blob/HEAD/CHANGELOG.md#2000---2026-03-31)

[Compare Source](https://github.com/raineorshine/npm-check-updates/compare/v19.6.6...v20.0.0)

##### Auto Cooldown

The cooldown option is now automatically applied from the respective package manager's config:

- **npm** - `min-release-age` ([#&#8203;1632](https://github.com/raineorshine/npm-check-updates/issues/1632))
- **yarn** - `npmMinimalAgeGate` (excluding `npmPreapprovedPackages`) ([#&#8203;1643](https://github.com/raineorshine/npm-check-updates/issues/1643))
- **pnpm** - `minimumReleaseAge` (excluding `minimumReleaseAgeExclude`) ([#&#8203;1639](https://github.com/raineorshine/npm-check-updates/issues/1639))

Why is this a breaking change?

- If you use any of the above configs, npm-check-updates will automatically exclude releases that do not exceed the specified minimum age as described in <https://github.com/raineorshine/npm-check-updates#cooldown>.
- Otherwise, you don't need to do anything.

##### Other changes

- Bump strip-ansi from 7.1.2 to 7.2.0 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1620](https://github.com/raineorshine/npm-check-updates/pull/1620)
- Bump lodash and [@&#8203;types/lodash](https://github.com/types/lodash) by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1615](https://github.com/raineorshine/npm-check-updates/pull/1615)
- Bump [@&#8203;typescript-eslint/eslint-plugin](https://github.com/typescript-eslint/eslint-plugin) from 8.44.1 to 8.57.2 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1619](https://github.com/raineorshine/npm-check-updates/pull/1619)
- Bump hosted-git-info from 9.0.0 to 9.0.2 by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1622](https://github.com/raineorshine/npm-check-updates/pull/1622)
- Bump glob and markdownlint-cli by [@&#8203;dependabot](https://github.com/dependabot)\[bot] in [#&#8203;1625](https://github.com/raineorshine/npm-check-updates/pull/1625)
- update dependencies; fix vulnerabilities by [@&#8203;onemen](https://github.com/onemen) in [#&#8203;1630](https://github.com/raineorshine/npm-check-updates/pull/1630)
- Potential fix for code scanning alert no. 13: Incomplete string escaping or encoding by [@&#8203;raineorshine](https://github.com/raineorshine) in [#&#8203;1640](https://github.com/raineorshine/npm-check-updates/pull/1640)

</details>

---

### Configuration

📅 **Schedule**: (UTC)

- Branch creation
  - At any time (no schedule defined)
- Automerge
  - At any time (no schedule defined)

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My4xMjEuMCIsInVwZGF0ZWRJblZlciI6IjQzLjEzNy4wIiwidGFyZ2V0QnJhbmNoIjoibmV4dCIsImxhYmVscyI6W119-->

Reviewed-on: https://git.valverde.cloud/Thilawyn/effect-fc/pulls/46
Co-authored-by: Renovate Bot <renovate-bot@valverde.cloud>
Co-committed-by: Renovate Bot <renovate-bot@valverde.cloud>

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@effect-fc/monorepo",
-  "packageManager": "bun@1.3.6",
+  "packageManager": "bun@1.3.11",
   "private": true,
   "workspaces": [
     "./packages/*"
@@ -15,12 +15,12 @@
     "clean:modules": "turbo clean:modules && rm -rf node_modules"
   },
   "devDependencies": {
-    "@biomejs/biome": "^2.3.11",
+    "@biomejs/biome": "^2.4.9",
-    "@effect/language-service": "^0.75.0",
+    "@effect/language-service": "^0.85.0",
-    "@types/bun": "^1.3.6",
+    "@types/bun": "^1.3.11",
-    "npm-check-updates": "^19.3.1",
+    "npm-check-updates": "^21.0.0",
     "npm-sort": "^0.0.4",
-    "turbo": "^2.7.5",
+    "turbo": "^2.8.21",
-    "typescript": "^5.9.3"
+    "typescript": "^6.0.2"
   }
 }

packages/docs/package.json

@@ -15,8 +15,8 @@
     "typecheck": "tsc"
   },
   "dependencies": {
-    "@docusaurus/core": "3.9.2",
+    "@docusaurus/core": "3.10.0",
-    "@docusaurus/preset-classic": "3.9.2",
+    "@docusaurus/preset-classic": "3.10.0",
     "@mdx-js/react": "^3.0.0",
     "clsx": "^2.0.0",
     "prism-react-renderer": "^2.3.0",
@@ -24,10 +24,10 @@
     "react-dom": "^19.0.0"
   },
   "devDependencies": {
-    "@docusaurus/module-type-aliases": "3.9.2",
+    "@docusaurus/module-type-aliases": "3.10.0",
-    "@docusaurus/tsconfig": "3.9.2",
+    "@docusaurus/tsconfig": "3.10.0",
-    "@docusaurus/types": "3.9.2",
+    "@docusaurus/types": "3.10.0",
-    "typescript": "~5.6.2"
+    "typescript": "~6.0.0"
   },
   "browserslist": {
     "production": [

packages/effect-fc/package.json

@@ -1,7 +1,7 @@
 {
   "name": "effect-fc",
   "description": "Write React function components with Effect",
-  "version": "0.2.4",
+  "version": "0.2.5",
   "type": "module",
   "files": [
     "./README.md",
@@ -38,11 +38,14 @@
     "clean:modules": "rm -rf node_modules"
   },
   "devDependencies": {
-    "@effect/platform-browser": "^0.74.0"
+    "@effect/platform-browser": "^0.76.0"
   },
   "peerDependencies": {
     "@types/react": "^19.2.0",
-    "effect": "^3.19.0",
+    "effect": "^3.21.0",
     "react": "^19.2.0"
+  },
+  "dependencies": {
+    "effect-lens": "^0.1.4"
   }
 }

packages/effect-fc/src/Form.ts

@@ -1,105 +1,101 @@
-import { Array, Cause, Chunk, type Context, type Duration, Effect, Equal, Exit, Fiber, flow, Hash, HashMap, identity, Option, ParseResult, Pipeable, Predicate, Ref, Schema, type Scope, Stream } from "effect"
+import { Array, Cause, Chunk, type Context, type Duration, Effect, Equal, Exit, Fiber, Function, identity, Option, ParseResult, Pipeable, Predicate, Schema, type Scope, Stream } from "effect"
 import type * as React from "react"
 import * as Component from "./Component.js"
+import * as Lens from "./Lens.js"
 import * as Mutation from "./Mutation.js"
-import * as PropertyPath from "./PropertyPath.js"
 import * as Result from "./Result.js"
 import * as Subscribable from "./Subscribable.js"
 import * as SubscriptionRef from "./SubscriptionRef.js"
-import * as SubscriptionSubRef from "./SubscriptionSubRef.js"
 
 
 export const FormTypeId: unique symbol = Symbol.for("@effect-fc/Form/Form")
 export type FormTypeId = typeof FormTypeId
 
-export interface Form<in out A, in out I = A, in out R = never, in out MA = void, in out ME = never, in out MR = never, in out MP = never>
+export interface Form<out P extends readonly PropertyKey[], in out A, in out I = A, in out ER = never, in out EW = never>
 extends Pipeable.Pipeable {
     readonly [FormTypeId]: FormTypeId
 
+    readonly path: P
+    readonly value: Subscribable.Subscribable<Option.Option<A>, ER, never>
+    readonly encodedValue: Lens.Lens<I, ER, EW, never, never>
+    readonly issues: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[], never, never>
+    readonly isValidating: Subscribable.Subscribable<boolean, ER, never>
+    readonly canSubmit: Subscribable.Subscribable<boolean, never, never>
+    readonly isSubmitting: Subscribable.Subscribable<boolean, never, never>
+}
+
+export class FormImpl<out P extends readonly PropertyKey[], in out A, in out I = A, in out ER = never, in out EW = never>
+extends Pipeable.Class() implements Form<P, A, I, ER, EW> {
+    readonly [FormTypeId]: FormTypeId = FormTypeId
+
+    constructor(
+        readonly path: P,
+        readonly value: Subscribable.Subscribable<Option.Option<A>, ER, never>,
+        readonly encodedValue: Lens.Lens<I, ER, EW, never, never>,
+        readonly issues: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[], never, never>,
+        readonly isValidating: Subscribable.Subscribable<boolean, never, never>,
+        readonly canSubmit: Subscribable.Subscribable<boolean, never, never>,
+        readonly isSubmitting: Subscribable.Subscribable<boolean, never, never>,
+    ) {
+        super()
+    }
+}
+
+
+export const RootFormTypeId: unique symbol = Symbol.for("@effect-fc/Form/RootForm")
+export type RootFormTypeId = typeof RootFormTypeId
+
+export interface RootForm<in out A, in out I = A, in out R = never, in out MA = void, in out ME = never, in out MR = never, in out MP = never>
+extends Form<readonly [], A, I, never, never> {
     readonly schema: Schema.Schema<A, I, R>
     readonly context: Context.Context<Scope.Scope | R>
     readonly mutation: Mutation.Mutation<
-        readonly [value: A, form: Form<A, I, R, unknown, unknown, unknown>],
+        readonly [value: A, form: RootForm<A, I, R, unknown, unknown, unknown>],
         MA, ME, MR, MP
     >
     readonly autosubmit: boolean
-    readonly debounce: Option.Option<Duration.DurationInput>
 
-    readonly value: Subscribable.Subscribable<Option.Option<A>>
+    readonly validationFiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>, never, never>
-    readonly encodedValue: SubscriptionRef.SubscriptionRef<I>
-    readonly error: Subscribable.Subscribable<Option.Option<ParseResult.ParseError>>
-    readonly validationFiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>>
-
-    readonly canSubmit: Subscribable.Subscribable<boolean>
-
-    field<const P extends PropertyPath.Paths<I>>(
-        path: P
-    ): Effect.Effect<FormField<PropertyPath.ValueFromPath<A, P>, PropertyPath.ValueFromPath<I, P>>>
 
     readonly run: Effect.Effect<void>
     readonly submit: Effect.Effect<Option.Option<Result.Final<MA, ME, MP>>, Cause.NoSuchElementException>
 }
 
-export class FormImpl<in out A, in out I = A, in out R = never, in out MA = void, in out ME = never, in out MR = never, in out MP = never>
+export class RootFormImpl<in out A, in out I = A, in out R = never, in out MA = void, in out ME = never, in out MR = never, in out MP = never>
-extends Pipeable.Class() implements Form<A, I, R, MA, ME, MR, MP> {
+extends Pipeable.Class() implements RootForm<A, I, R, MA, ME, MR, MP> {
     readonly [FormTypeId]: FormTypeId = FormTypeId
+    readonly [RootFormTypeId]: RootFormTypeId = RootFormTypeId
+
+    readonly path = [] as const
 
     constructor(
         readonly schema: Schema.Schema<A, I, R>,
         readonly context: Context.Context<Scope.Scope | R>,
         readonly mutation: Mutation.Mutation<
-            readonly [value: A, form: Form<A, I, R, unknown, unknown, unknown>],
+            readonly [value: A, form: RootForm<A, I, R, unknown, unknown, unknown>],
             MA, ME, MR, MP
         >,
         readonly autosubmit: boolean,
-        readonly debounce: Option.Option<Duration.DurationInput>,
 
-        readonly value: SubscriptionRef.SubscriptionRef<Option.Option<A>>,
+        readonly value: Lens.Lens<Option.Option<A>, never, never, never, never>,
-        readonly encodedValue: SubscriptionRef.SubscriptionRef<I>,
+        readonly encodedValue: Lens.Lens<I, never, never, never, never>,
-        readonly error: SubscriptionRef.SubscriptionRef<Option.Option<ParseResult.ParseError>>,
+        readonly issues: Lens.Lens<readonly ParseResult.ArrayFormatterIssue[], never, never, never, never>,
-        readonly validationFiber: SubscriptionRef.SubscriptionRef<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>>,
+        readonly validationFiber: Lens.Lens<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>, never, never, never, never>,
+        readonly isValidating: Subscribable.Subscribable<boolean, never, never>,
+
+        readonly canSubmit: Subscribable.Subscribable<boolean, never, never>,
+        readonly isSubmitting: Subscribable.Subscribable<boolean, never, never>,
 
         readonly runSemaphore: Effect.Semaphore,
-        readonly fieldCache: Ref.Ref<HashMap.HashMap<FormFieldKey, FormField<unknown, unknown>>>,
     ) {
         super()
-
-        this.canSubmit = Subscribable.map(
-            Subscribable.zipLatestAll(this.value, this.error, this.validationFiber, this.mutation.result),
-            ([value, error, validationFiber, result]) => (
-                Option.isSome(value) &&
-                Option.isNone(error) &&
-                Option.isNone(validationFiber) &&
-                !(Result.isRunning(result) || Result.hasRefreshingFlag(result))
-            ),
-        )
     }
 
-    field<const P extends PropertyPath.Paths<I>>(
-        path: P
-    ): Effect.Effect<FormField<PropertyPath.ValueFromPath<A, P>, PropertyPath.ValueFromPath<I, P>>> {
-        const key = new FormFieldKey(path)
-        return this.fieldCache.pipe(
-            Effect.map(HashMap.get(key)),
-            Effect.flatMap(Option.match({
-                onSome: v => Effect.succeed(v as FormField<PropertyPath.ValueFromPath<A, P>, PropertyPath.ValueFromPath<I, P>>),
-                onNone: () => Effect.tap(
-                    Effect.succeed(makeFormField(this as Form<A, I, R, MA, ME, MR, MP>, path)),
-                    v => Ref.update(this.fieldCache, HashMap.set(key, v as FormField<unknown, unknown>)),
-                ),
-            })),
-        )
-    }
-
-    readonly canSubmit: Subscribable.Subscribable<boolean>
-
     get run(): Effect.Effect<void> {
         return this.runSemaphore.withPermits(1)(Stream.runForEach(
-            this.encodedValue.changes.pipe(
+            this.encodedValue.changes,
-                Option.isSome(this.debounce) ? Stream.debounce(this.debounce.value) : identity
-            ),
 
-            encodedValue => this.validationFiber.pipe(
+            encodedValue => Lens.get(this.validationFiber).pipe(
                 Effect.andThen(Option.match({
                     onSome: Fiber.interrupt,
                     onNone: () => Effect.void,
@@ -110,18 +106,21 @@ extends Pipeable.Class() implements Form<A, I, R, MA, ME, MR, MP> {
                         exit => Effect.andThen(
                             Exit.matchEffect(exit, {
                                 onSuccess: v => Effect.andThen(
-                                    Ref.set(this.value, Option.some(v)),
+                                    Lens.set(this.value, Option.some(v)),
-                                    Ref.set(this.error, Option.none()),
+                                    Lens.set(this.issues, Array.empty()),
                                 ),
                                 onFailure: c => Option.match(Chunk.findFirst(Cause.failures(c), e => e._tag === "ParseError"), {
-                                    onSome: e => Ref.set(this.error, Option.some(e)),
+                                    onSome: e => Effect.flatMap(
+                                        ParseResult.ArrayFormatter.formatError(e),
+                                        v => Lens.set(this.issues, v),
+                                    ),
                                     onNone: () => Effect.void,
                                 }),
                             }),
-                            Ref.set(this.validationFiber, Option.none()),
+                            Lens.set(this.validationFiber, Option.none()),
                         ),
                     )).pipe(
-                        Effect.tap(fiber => Ref.set(this.validationFiber, Option.some(fiber))),
+                        Effect.tap(fiber => Lens.set(this.validationFiber, Option.some(fiber))),
                         Effect.andThen(Fiber.join),
                         Effect.andThen(value => this.autosubmit
                             ? Effect.asVoid(Effect.forkScoped(this.submitValue(value)))
@@ -136,7 +135,7 @@ extends Pipeable.Class() implements Form<A, I, R, MA, ME, MR, MP> {
     }
 
     get submit(): Effect.Effect<Option.Option<Result.Final<MA, ME, MP>>, Cause.NoSuchElementException> {
-        return this.value.pipe(
+        return Lens.get(this.value).pipe(
             Effect.andThen(identity),
             Effect.andThen(value => this.submitValue(value)),
         )
@@ -153,7 +152,10 @@ extends Pipeable.Class() implements Form<A, I, R, MA, ME, MR, MP> {
                             e => e._tag === "ParseError",
                         ),
                         {
-                            onSome: e => Ref.set(this.error, Option.some(e)),
+                            onSome: e => Effect.flatMap(
+                                ParseResult.ArrayFormatter.formatError(e),
+                                v => Lens.set(this.issues, v),
+                            ),
                             onNone: () => Effect.void,
                         },
                     )
@@ -164,42 +166,59 @@ extends Pipeable.Class() implements Form<A, I, R, MA, ME, MR, MP> {
     }
 }
 
-export const isForm = (u: unknown): u is Form<unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, FormTypeId)
+
+export const isForm = (u: unknown): u is Form<readonly PropertyKey[], unknown, unknown> => Predicate.hasProperty(u, FormTypeId)
+export const isRootForm = (u: unknown): u is RootForm<readonly PropertyKey[], unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, RootFormTypeId)
+
 
 export declare namespace make {
     export interface Options<in out A, in out I = A, in out R = never, in out MA = void, in out ME = never, in out MR = never, in out MP = never>
     extends Mutation.make.Options<
-        readonly [value: NoInfer<A>, form: Form<NoInfer<A>, NoInfer<I>, NoInfer<R>, unknown, unknown, unknown>],
+        readonly [value: NoInfer<A>, form: RootForm<NoInfer<A>, NoInfer<I>, NoInfer<R>, unknown, unknown, unknown>],
         MA, ME, MR, MP
     > {
         readonly schema: Schema.Schema<A, I, R>
         readonly initialEncodedValue: NoInfer<I>
         readonly autosubmit?: boolean
-        readonly debounce?: Duration.DurationInput
     }
 }
 
 export const make = Effect.fnUntraced(function* <A, I = A, R = never, MA = void, ME = never, MR = never, MP = never>(
     options: make.Options<A, I, R, MA, ME, MR, MP>
 ): Effect.fn.Return<
-    Form<A, I, R, MA, ME, Result.forkEffect.OutputContext<MA, ME, MR, MP>, MP>,
+    RootForm<A, I, R, MA, ME, Result.forkEffect.OutputContext<MR, MP>, MP>,
     never,
-    Scope.Scope | R | Result.forkEffect.OutputContext<MA, ME, MR, MP>
+    Scope.Scope | R | Result.forkEffect.OutputContext<MR, MP>
 > {
-    return new FormImpl(
+    const mutation = yield* Mutation.make(options)
+    const valueLens = Lens.fromSubscriptionRef(yield* SubscriptionRef.make(Option.none<A>()))
+    const issuesLens = Lens.fromSubscriptionRef(yield* SubscriptionRef.make<readonly ParseResult.ArrayFormatterIssue[]>(Array.empty()))
+    const validationFiberLens = Lens.fromSubscriptionRef(yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, ParseResult.ParseError>>()))
+
+    return new RootFormImpl(
         options.schema,
         yield* Effect.context<Scope.Scope | R>(),
-        yield* Mutation.make(options),
+        mutation,
         options.autosubmit ?? false,
-        Option.fromNullable(options.debounce),
 
-        yield* SubscriptionRef.make(Option.none<A>()),
+        valueLens,
-        yield* SubscriptionRef.make(options.initialEncodedValue),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(options.initialEncodedValue)),
-        yield* SubscriptionRef.make(Option.none<ParseResult.ParseError>()),
+        issuesLens,
-        yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, ParseResult.ParseError>>()),
+        validationFiberLens,
+        Subscribable.map(validationFiberLens, Option.isSome),
+
+        Subscribable.map(
+            Subscribable.zipLatestAll(valueLens, issuesLens, validationFiberLens, mutation.result),
+            ([value, issues, validationFiber, result]) => (
+                Option.isSome(value) &&
+                Array.isEmptyReadonlyArray(issues) &&
+                Option.isNone(validationFiber) &&
+                !(Result.isRunning(result) || Result.hasRefreshingFlag(result))
+            ),
+        ),
+        Subscribable.map(mutation.result, result => Result.isRunning(result) || Result.hasRefreshingFlag(result)),
 
         yield* Effect.makeSemaphore(1),
-        yield* Ref.make(HashMap.empty<FormFieldKey, FormField<unknown, unknown>>()),
     )
 })
 
@@ -211,83 +230,125 @@ export declare namespace service {
 export const service = <A, I = A, R = never, MA = void, ME = never, MR = never, MP = never>(
     options: service.Options<A, I, R, MA, ME, MR, MP>
 ): Effect.Effect<
-    Form<A, I, R, MA, ME, Result.forkEffect.OutputContext<MA, ME, MR, MP>, MP>,
+    RootForm<A, I, R, MA, ME, Result.forkEffect.OutputContext<MR, MP>, MP>,
     never,
-    Scope.Scope | R | Result.forkEffect.OutputContext<MA, ME, MR, MP>
+    Scope.Scope | R | Result.forkEffect.OutputContext<MR, MP>
 > => Effect.tap(
     make(options),
     form => Effect.forkScoped(form.run),
 )
 
 
-export const FormFieldTypeId: unique symbol = Symbol.for("@effect-fc/Form/FormField")
+const filterIssuesByPath = (
-export type FormFieldTypeId = typeof FormFieldTypeId
+    issues: readonly ParseResult.ArrayFormatterIssue[],
-
+    path: readonly PropertyKey[],
-export interface FormField<in out A, in out I = A>
+): readonly ParseResult.ArrayFormatterIssue[] => Array.filter(issues, issue =>
-extends Pipeable.Pipeable {
+    issue.path.length >= path.length && Array.every(path, (p, i) => p === issue.path[i])
-    readonly [FormFieldTypeId]: FormFieldTypeId
-
-    readonly value: Subscribable.Subscribable<Option.Option<A>, Cause.NoSuchElementException>
-    readonly encodedValue: SubscriptionRef.SubscriptionRef<I>
-    readonly issues: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[]>
-    readonly isValidating: Subscribable.Subscribable<boolean>
-    readonly isSubmitting: Subscribable.Subscribable<boolean>
-}
-
-class FormFieldImpl<in out A, in out I = A>
-extends Pipeable.Class() implements FormField<A, I> {
-    readonly [FormFieldTypeId]: FormFieldTypeId = FormFieldTypeId
-
-    constructor(
-        readonly value: Subscribable.Subscribable<Option.Option<A>, Cause.NoSuchElementException>,
-        readonly encodedValue: SubscriptionRef.SubscriptionRef<I>,
-        readonly issues: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[]>,
-        readonly isValidating: Subscribable.Subscribable<boolean>,
-        readonly isSubmitting: Subscribable.Subscribable<boolean>,
-    ) {
-        super()
-    }
-}
-
-const FormFieldKeyTypeId: unique symbol = Symbol.for("@effect-fc/Form/FormFieldKey")
-type FormFieldKeyTypeId = typeof FormFieldKeyTypeId
-
-class FormFieldKey implements Equal.Equal {
-    readonly [FormFieldKeyTypeId]: FormFieldKeyTypeId = FormFieldKeyTypeId
-    constructor(readonly path: PropertyPath.PropertyPath) {}
-
-    [Equal.symbol](that: Equal.Equal) {
-        return isFormFieldKey(that) && PropertyPath.equivalence(this.path, that.path)
-    }
-    [Hash.symbol]() {
-        return Hash.array(this.path)
-    }
-}
-
-export const isFormField = (u: unknown): u is FormField<unknown, unknown> => Predicate.hasProperty(u, FormFieldTypeId)
-const isFormFieldKey = (u: unknown): u is FormFieldKey => Predicate.hasProperty(u, FormFieldKeyTypeId)
-
-export const makeFormField = <A, I, R, MA, ME, MR, MP, const P extends PropertyPath.Paths<NoInfer<I>>>(
-    self: Form<A, I, R, MA, ME, MR, MP>,
-    path: P,
-): FormField<PropertyPath.ValueFromPath<A, P>, PropertyPath.ValueFromPath<I, P>> => {
-    return new FormFieldImpl(
-        Subscribable.mapEffect(self.value, Option.match({
-            onSome: v => Option.map(PropertyPath.get(v, path), Option.some),
-            onNone: () => Option.some(Option.none()),
-        })),
-        SubscriptionSubRef.makeFromPath(self.encodedValue, path),
-        Subscribable.mapEffect(self.error, Option.match({
-            onSome: flow(
-                ParseResult.ArrayFormatter.formatError,
-                Effect.map(Array.filter(issue => PropertyPath.equivalence(issue.path, path))),
-            ),
-            onNone: () => Effect.succeed([]),
-        })),
-        Subscribable.map(self.validationFiber, Option.isSome),
-        Subscribable.map(self.mutation.result, result => Result.isRunning(result) || Result.hasRefreshingFlag(result)),
 )
-}
+
+export const focusObjectField: {
+    <P extends readonly PropertyKey[], A extends object, I extends object, ER, EW, K extends keyof A & keyof I>(
+        self: Form<P, A, I, ER, EW>,
+        key: K,
+    ): Form<readonly [...P, K], A[K], I[K], ER, EW>
+    <P extends readonly PropertyKey[], A extends object, I extends object, ER, EW, K extends keyof A & keyof I>(
+        key: K,
+    ): (self: Form<P, A, I, ER, EW>) => Form<readonly [...P, K], A[K], I[K], ER, EW>
+} = Function.dual(2, <P extends readonly PropertyKey[], A extends object, I extends object, ER, EW, K extends keyof A & keyof I>(
+    self: Form<P, A, I, ER, EW>,
+    key: K,
+): Form<readonly [...P, K], A[K], I[K], ER, EW> => {
+    const form = self as FormImpl<P, A, I, ER, EW>
+    const path = [...form.path, key] as const
+
+    return new FormImpl(
+        path,
+        Subscribable.mapOption(form.value, a => a[key]),
+        Lens.focusObjectField(form.encodedValue, key),
+        Subscribable.map(form.issues, issues => filterIssuesByPath(issues, path)),
+        form.isValidating,
+        form.canSubmit,
+        form.isSubmitting,
+    )
+})
+
+export const focusArrayAt: {
+    <P extends readonly PropertyKey[], A extends readonly any[], I extends readonly any[], ER, EW>(
+        self: Form<P, A, I, ER, EW>,
+        index: number,
+    ): Form<readonly [...P, number], A[number], I[number], ER | Cause.NoSuchElementException, EW | Cause.NoSuchElementException>
+    <P extends readonly PropertyKey[], A extends readonly any[], I extends readonly any[], ER, EW>(
+        index: number,
+    ): (self: Form<P, A, I, ER, EW>) => Form<readonly [...P, number], A[number], I[number], ER | Cause.NoSuchElementException, EW | Cause.NoSuchElementException>
+} = Function.dual(2, <P extends readonly PropertyKey[], A extends readonly any[], I extends readonly any[], ER, EW>(
+    self: Form<P, A, I, ER, EW>,
+    index: number,
+): Form<readonly [...P, number], A[number], I[number], ER | Cause.NoSuchElementException, EW | Cause.NoSuchElementException> => {
+    const form = self as FormImpl<P, A, I, ER, EW>
+    const path = [...form.path, index] as const
+
+    return new FormImpl(
+        path,
+        Subscribable.mapOptionEffect(form.value, Array.get(index)),
+        Lens.focusArrayAt(form.encodedValue, index),
+        Subscribable.map(form.issues, issues => filterIssuesByPath(issues, path)),
+        form.isValidating,
+        form.canSubmit,
+        form.isSubmitting,
+    )
+})
+
+export const focusTupleAt: {
+    <P extends readonly PropertyKey[], A extends readonly [any, ...any[]], I extends readonly [any, ...any[]], ER, EW, K extends number>(
+        self: Form<P, A, I, ER, EW>,
+        index: K,
+    ): Form<readonly [...P, K], A[K], I[K], ER, EW>
+    <P extends readonly PropertyKey[], A extends readonly [any, ...any[]], I extends readonly [any, ...any[]], ER, EW, K extends number>(
+        index: K,
+    ): (self: Form<P, A, I, ER, EW>) => Form<readonly [...P, K], A[K], I[K], ER, EW>
+} = Function.dual(2, <P extends readonly PropertyKey[], A extends readonly [any, ...any[]], I extends readonly [any, ...any[]], ER, EW, K extends number>(
+    self: Form<P, A, I, ER, EW>,
+    index: K,
+): Form<readonly [...P, K], A[K], I[K], ER, EW> => {
+    const form = self as FormImpl<P, A, I, ER, EW>
+    const path = [...form.path, index] as const
+
+    return new FormImpl(
+        path,
+        Subscribable.mapOption(form.value, Array.unsafeGet(index)),
+        Lens.focusTupleAt(form.encodedValue, index),
+        Subscribable.map(form.issues, issues => filterIssuesByPath(issues, path)),
+        form.isValidating,
+        form.canSubmit,
+        form.isSubmitting,
+    )
+})
+
+export const focusChunkAt: {
+    <P extends readonly PropertyKey[], A, I, ER, EW>(
+        self: Form<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>,
+        index: number,
+    ): Form<readonly [...P, number], A, I, ER | Cause.NoSuchElementException, EW>
+    <P extends readonly PropertyKey[], A, I, ER, EW>(
+        index: number,
+    ): (self: Form<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>) => Form<readonly [...P, number], A, I, ER | Cause.NoSuchElementException, EW>
+} = Function.dual(2, <P extends readonly PropertyKey[], A, I, ER, EW>(
+    self: Form<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>,
+    index: number,
+): Form<readonly [...P, number], A, I, ER | Cause.NoSuchElementException, EW> => {
+    const form = self as FormImpl<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>
+    const path = [...form.path, index] as const
+
+    return new FormImpl(
+        path,
+        Subscribable.mapOptionEffect(form.value, Chunk.get(index)),
+        Lens.focusChunkAt(form.encodedValue, index),
+        Subscribable.map(form.issues, issues => filterIssuesByPath(issues, path)),
+        form.isValidating,
+        form.canSubmit,
+        form.isSubmitting,
+    )
+})
 
 
 export namespace useInput {
@@ -301,33 +362,39 @@ export namespace useInput {
     }
 }
 
-export const useInput = Effect.fnUntraced(function* <A, I>(
+export const useInput = Effect.fnUntraced(function* <P extends readonly PropertyKey[], A, I, ER, EW>(
-    field: FormField<A, I>,
+    form: Form<P, A, I, ER, EW>,
     options?: useInput.Options,
-): Effect.fn.Return<useInput.Success<I>, Cause.NoSuchElementException, Scope.Scope> {
+): Effect.fn.Return<useInput.Success<I>, ER, Scope.Scope> {
-    const internalValueRef = yield* Component.useOnChange(() => Effect.tap(
+    const internalValueLens = yield* Component.useOnChange(() => Effect.gen(function*() {
-        Effect.andThen(field.encodedValue, SubscriptionRef.make),
+        const internalValueLens = yield* Lens.get(form.encodedValue).pipe(
-        internalValueRef => Effect.forkScoped(Effect.all([
+            Effect.flatMap(SubscriptionRef.make),
+            Effect.map(Lens.fromSubscriptionRef),
+        )
+
+        yield* Effect.forkScoped(Effect.all([
             Stream.runForEach(
-                Stream.drop(field.encodedValue, 1),
+                Stream.drop(form.encodedValue.changes, 1),
                 upstreamEncodedValue => Effect.whenEffect(
-                    Ref.set(internalValueRef, upstreamEncodedValue),
+                    Lens.set(internalValueLens, upstreamEncodedValue),
-                    Effect.andThen(internalValueRef, internalValue => !Equal.equals(upstreamEncodedValue, internalValue)),
+                    Effect.andThen(Lens.get(internalValueLens), internalValue => !Equal.equals(upstreamEncodedValue, internalValue)),
                 ),
             ),
 
             Stream.runForEach(
-                internalValueRef.changes.pipe(
+                internalValueLens.changes.pipe(
                     Stream.drop(1),
                     Stream.changesWith(Equal.equivalence()),
                     options?.debounce ? Stream.debounce(options.debounce) : identity,
                 ),
-                internalValue => Ref.set(field.encodedValue, internalValue),
+                internalValue => Lens.set(form.encodedValue, internalValue),
             ),
-        ], { concurrency: "unbounded" })),
+        ], { concurrency: "unbounded" }))
-    ), [field, options?.debounce])
 
-    const [value, setValue] = yield* SubscriptionRef.useSubscriptionRefState(internalValueRef)
+        return internalValueLens
+    }), [form, options?.debounce])
+
+    const [value, setValue] = yield* Lens.useState(internalValueLens)
     return { value, setValue }
 })
 
@@ -342,55 +409,63 @@ export namespace useOptionalInput {
     }
 }
 
-export const useOptionalInput = Effect.fnUntraced(function* <A, I>(
+export const useOptionalInput = Effect.fnUntraced(function* <P extends readonly PropertyKey[], A, I, ER, EW>(
-    field: FormField<A, Option.Option<I>>,
+    field: Form<P, A, Option.Option<I>, ER, EW>,
     options: useOptionalInput.Options<I>,
-): Effect.fn.Return<useOptionalInput.Success<I>, Cause.NoSuchElementException, Scope.Scope> {
+): Effect.fn.Return<useOptionalInput.Success<I>, ER, Scope.Scope> {
-    const [enabledRef, internalValueRef] = yield* Component.useOnChange(() => Effect.tap(
+    const [enabledLens, internalValueLens] = yield* Component.useOnChange(() => Effect.gen(function*() {
-        Effect.andThen(
+        const [enabledLens, internalValueLens] = yield* Effect.flatMap(
-            field.encodedValue,
+            Lens.get(field.encodedValue),
             Option.match({
-                onSome: v => Effect.all([SubscriptionRef.make(true), SubscriptionRef.make(v)]),
+                onSome: v => Effect.all([
-                onNone: () => Effect.all([SubscriptionRef.make(false), SubscriptionRef.make(options.defaultValue)]),
+                    Effect.map(SubscriptionRef.make(true), Lens.fromSubscriptionRef),
+                    Effect.map(SubscriptionRef.make(v), Lens.fromSubscriptionRef),
+                ]),
+                onNone: () => Effect.all([
+                    Effect.map(SubscriptionRef.make(false), Lens.fromSubscriptionRef),
+                    Effect.map(SubscriptionRef.make(options.defaultValue), Lens.fromSubscriptionRef),
+                ]),
             }),
-        ),
+        )
 
-        ([enabledRef, internalValueRef]) => Effect.forkScoped(Effect.all([
+        yield* Effect.forkScoped(Effect.all([
             Stream.runForEach(
-                Stream.drop(field.encodedValue, 1),
+                Stream.drop(field.encodedValue.changes, 1),
 
                 upstreamEncodedValue => Effect.whenEffect(
                     Option.match(upstreamEncodedValue, {
                         onSome: v => Effect.andThen(
-                            Ref.set(enabledRef, true),
+                            Lens.set(enabledLens, true),
-                            Ref.set(internalValueRef, v),
+                            Lens.set(internalValueLens, v),
                         ),
                         onNone: () => Effect.andThen(
-                            Ref.set(enabledRef, false),
+                            Lens.set(enabledLens, false),
-                            Ref.set(internalValueRef, options.defaultValue),
+                            Lens.set(internalValueLens, options.defaultValue),
                         ),
                     }),
 
                     Effect.andThen(
-                        Effect.all([enabledRef, internalValueRef]),
+                        Effect.all([Lens.get(enabledLens), Lens.get(internalValueLens)]),
                         ([enabled, internalValue]) => !Equal.equals(upstreamEncodedValue, enabled ? Option.some(internalValue) : Option.none()),
                     ),
                 ),
             ),
 
             Stream.runForEach(
-                enabledRef.changes.pipe(
+                enabledLens.changes.pipe(
-                    Stream.zipLatest(internalValueRef.changes),
+                    Stream.zipLatest(internalValueLens.changes),
                     Stream.drop(1),
                     Stream.changesWith(Equal.equivalence()),
                     options?.debounce ? Stream.debounce(options.debounce) : identity,
                 ),
-                ([enabled, internalValue]) => Ref.set(field.encodedValue, enabled ? Option.some(internalValue) : Option.none()),
+                ([enabled, internalValue]) => Lens.set(field.encodedValue, enabled ? Option.some(internalValue) : Option.none()),
             ),
-        ], { concurrency: "unbounded" })),
+        ], { concurrency: "unbounded" }))
-    ), [field, options.debounce])
 
-    const [enabled, setEnabled] = yield* SubscriptionRef.useSubscriptionRefState(enabledRef)
+        return [enabledLens, internalValueLens] as const
-    const [value, setValue] = yield* SubscriptionRef.useSubscriptionRefState(internalValueRef)
+    }), [field, options.debounce])
+
+    const [enabled, setEnabled] = yield* Lens.useState(enabledLens)
+    const [value, setValue] = yield* Lens.useState(internalValueLens)
     return { enabled, setEnabled, value, setValue }
 })

packages/effect-fc/src/Lens.ts

@@ -0,0 +1,63 @@
+import { Effect, Equivalence, Stream } from "effect"
+import { Lens } from "effect-lens"
+import * as React from "react"
+import * as Component from "./Component.js"
+import * as SetStateAction from "./SetStateAction.js"
+import * as SubscriptionRef from "./SubscriptionRef.js"
+
+
+export * from "effect-lens/Lens"
+
+export declare namespace useState {
+    export interface Options<A> {
+        readonly equivalence?: Equivalence.Equivalence<A>
+    }
+}
+
+export const useState = Effect.fnUntraced(function* <A, ER, EW, RR, RW>(
+    lens: Lens.Lens<A, ER, EW, RR, RW>,
+    options?: useState.Options<NoInfer<A>>,
+): Effect.fn.Return<readonly [A, React.Dispatch<React.SetStateAction<A>>], ER, RR | RW> {
+    const [reactStateValue, setReactStateValue] = React.useState(yield* Component.useOnMount(() => Lens.get(lens)))
+
+    yield* Component.useReactEffect(() => Effect.forkScoped(
+        Stream.runForEach(
+            Stream.changesWith(lens.changes, options?.equivalence ?? Equivalence.strict()),
+            v => Effect.sync(() => setReactStateValue(v)),
+        )
+    ), [lens])
+
+    const setValue = yield* Component.useCallbackSync(
+        (setStateAction: React.SetStateAction<A>) => Effect.andThen(
+            Lens.updateAndGet(lens, prevState => SetStateAction.value(setStateAction, prevState)),
+            v => setReactStateValue(v),
+        ),
+        [lens],
+    )
+
+    return [reactStateValue, setValue]
+})
+
+export declare namespace useFromState {
+    export interface Options<A> {
+        readonly equivalence?: Equivalence.Equivalence<A>
+    }
+}
+
+export const useFromState = Effect.fnUntraced(function* <A>(
+    [value, setValue]: readonly [A, React.Dispatch<React.SetStateAction<A>>],
+    options?: useFromState.Options<NoInfer<A>>,
+): Effect.fn.Return<Lens.Lens<A, never, never, never, never>> {
+    const lens = yield* Component.useOnMount(() => Effect.map(
+        SubscriptionRef.make(value),
+        Lens.fromSubscriptionRef,
+    ))
+
+    yield* Component.useReactEffect(() => Effect.forkScoped(Stream.runForEach(
+        Stream.changesWith(lens.changes, options?.equivalence ?? Equivalence.strict()),
+        v => Effect.sync(() => setValue(v)),
+    )), [setValue])
+    yield* Component.useReactEffect(() => Lens.set(lens, value), [value])
+
+    return lens
+})

packages/effect-fc/src/Mutation.ts

@@ -111,12 +111,12 @@ export declare namespace make {
 export const make = Effect.fnUntraced(function* <const K extends Mutation.AnyKey = never, A = void, E = never, R = never, P = never>(
     options: make.Options<K, A, E, R, P>
 ): Effect.fn.Return<
-    Mutation<K, A, E, Result.forkEffect.OutputContext<A, E, R, P>, P>,
+    Mutation<K, A, E, Result.forkEffect.OutputContext<R, P>, P>,
     never,
-    Scope.Scope | Result.forkEffect.OutputContext<A, E, R, P>
+    Scope.Scope | Result.forkEffect.OutputContext<R, P>
 > {
     return new MutationImpl(
-        yield* Effect.context<Scope.Scope | Result.forkEffect.OutputContext<A, E, R, P>>(),
+        yield* Effect.context<Scope.Scope | Result.forkEffect.OutputContext<R, P>>(),
         options.f as any,
         options.initialProgress as P,
 

packages/effect-fc/src/PropertyPath.test.ts

@@ -0,0 +1,67 @@
+import { describe, expect, test } from "bun:test"
+import { Option } from "effect"
+import * as PropertyPath from "./PropertyPath.js"
+
+
+describe("immutableSet with arrays", () => {
+    test("sets a top-level array element", () => {
+        const arr = [1, 2, 3]
+        const result = PropertyPath.immutableSet(arr, [1], 99)
+        expect(result).toEqual(Option.some([1, 99, 3]))
+    })
+
+    test("does not mutate the original array", () => {
+        const arr = [1, 2, 3]
+        PropertyPath.immutableSet(arr, [0], 42)
+        expect(arr).toEqual([1, 2, 3])
+    })
+
+    test("sets the first element of an array", () => {
+        const arr = ["a", "b", "c"]
+        const result = PropertyPath.immutableSet(arr, [0], "z")
+        expect(result).toEqual(Option.some(["z", "b", "c"]))
+    })
+
+    test("sets the last element of an array", () => {
+        const arr = [10, 20, 30]
+        const result = PropertyPath.immutableSet(arr, [2], 99)
+        expect(result).toEqual(Option.some([10, 20, 99]))
+    })
+
+    test("sets a nested array element inside an object", () => {
+        const obj = { tags: ["foo", "bar", "baz"] }
+        const result = PropertyPath.immutableSet(obj, ["tags", 1], "qux")
+        expect(result).toEqual(Option.some({ tags: ["foo", "qux", "baz"] }))
+    })
+
+    test("sets a deeply nested value inside an array of objects", () => {
+        const obj = { items: [{ name: "alice" }, { name: "bob" }] }
+        const result = PropertyPath.immutableSet(obj, ["items", 0, "name"], "charlie")
+        expect(result).toEqual(Option.some({ items: [{ name: "charlie" }, { name: "bob" }] }))
+    })
+
+    test("sets a value in a nested array", () => {
+        const matrix = [[1, 2], [3, 4]]
+        const result = PropertyPath.immutableSet(matrix, [1, 0], 99)
+        expect(result).toEqual(Option.some([[1, 2], [99, 4]]))
+    })
+
+    test("returns Option.none() for an out-of-bounds index", () => {
+        const arr = [1, 2, 3]
+        const result = PropertyPath.immutableSet(arr, [5], 99)
+        expect(result).toEqual(Option.none())
+    })
+
+    test("returns Option.none() for a non-numeric key on an array", () => {
+        const arr = [1, 2, 3]
+        // @ts-expect-error intentionally wrong key type
+        const result = PropertyPath.immutableSet(arr, ["length"], 0)
+        expect(result).toEqual(Option.none())
+    })
+
+    test("empty path returns Option.some of the value itself", () => {
+        const arr = [1, 2, 3]
+        const result = PropertyPath.immutableSet(arr, [], [9, 9, 9] as any)
+        expect(result).toEqual(Option.some([9, 9, 9]))
+    })
+})

packages/effect-fc/src/Query.ts

@@ -281,14 +281,14 @@ export declare namespace make {
 export const make = Effect.fnUntraced(function* <K extends Query.AnyKey, A, KE = never, KR = never, E = never, R = never, P = never>(
     options: make.Options<K, A, KE, KR, E, R, P>
 ): Effect.fn.Return<
-    Query<K, A, KE, KR, E, Result.forkEffect.OutputContext<A, E, R, P>, P>,
+    Query<K, A, KE, KR, E, Result.forkEffect.OutputContext<R, P>, P>,
     never,
-    Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<A, E, R, P>
+    Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<R, P>
 > {
     const client = yield* QueryClient.QueryClient
 
-    return new QueryImpl<K, A, KE, KR, E, Result.forkEffect.OutputContext<A, E, R, P>, P>(
+    return new QueryImpl<K, A, KE, KR, E, Result.forkEffect.OutputContext<R, P>, P>(
-        yield* Effect.context<Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<A, E, R, P>>(),
+        yield* Effect.context<Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<R, P>>(),
         options.key,
         options.f as any,
         options.initialProgress as P,
@@ -308,9 +308,9 @@ export const make = Effect.fnUntraced(function* <K extends Query.AnyKey, A, KE =
 export const service = <K extends Query.AnyKey, A, KE = never, KR = never, E = never, R = never, P = never>(
     options: make.Options<K, A, KE, KR, E, R, P>
 ): Effect.Effect<
-    Query<K, A, KE, KR, E, Result.forkEffect.OutputContext<A, E, R, P>, P>,
+    Query<K, A, KE, KR, E, Result.forkEffect.OutputContext<R, P>, P>,
     never,
-    Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<A, E, R, P>
+    Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<R, P>
 > => Effect.tap(
     make(options),
     query => Effect.forkScoped(query.run),

packages/effect-fc/src/Result.ts

@@ -1,4 +1,5 @@
-import { Cause, Context, Data, Effect, Equal, Exit, type Fiber, Hash, Layer, Match, Pipeable, Predicate, PubSub, pipe, Ref, type Scope, Stream, Subscribable } from "effect"
+import { Cause, Context, Data, Effect, Equal, Exit, type Fiber, Hash, Layer, Match, pipe, Pipeable, Predicate, PubSub, Ref, type Scope, Stream, type Subscribable, SynchronizedRef } from "effect"
+import { Lens } from "effect-lens"
 
 
 export const ResultTypeId: unique symbol = Symbol.for("@effect-fc/Result/Result")
@@ -15,10 +16,6 @@ export type Final<A, E = never, P = never> = (Success<A> | Failure<E>) & ({} | F
 export type Flags<P = never> = WillFetch | WillRefresh | Refreshing<P>
 
 export declare namespace Result {
-    export interface Prototype extends Pipeable.Pipeable, Equal.Equal {
-        readonly [ResultTypeId]: ResultTypeId
-    }
-
     export type Success<R extends Result<any, any, any>> = [R] extends [Result<infer A, infer _E, infer _P>] ? A : never
     export type Failure<R extends Result<any, any, any>> = [R] extends [Result<infer _A, infer E, infer _P>] ? E : never
     export type Progress<R extends Result<any, any, any>> = [R] extends [Result<infer _A, infer _E, infer P>] ? P : never
@@ -28,21 +25,21 @@ export declare namespace Flags {
     export type Keys = keyof WillFetch & WillRefresh & Refreshing<any>
 }
 
-export interface Initial extends Result.Prototype {
+export interface Initial extends ResultPrototype {
     readonly _tag: "Initial"
 }
 
-export interface Running<P = never> extends Result.Prototype {
+export interface Running<P = never> extends ResultPrototype {
     readonly _tag: "Running"
     readonly progress: P
 }
 
-export interface Success<A> extends Result.Prototype {
+export interface Success<A> extends ResultPrototype {
     readonly _tag: "Success"
     readonly value: A
 }
 
-export interface Failure<E = never> extends Result.Prototype {
+export interface Failure<E = never> extends ResultPrototype {
     readonly _tag: "Failure"
     readonly cause: Cause.Cause<E>
 }
@@ -61,7 +58,11 @@ export interface Refreshing<P = never> {
 }
 
 
-const ResultPrototype = Object.freeze({
+export interface ResultPrototype extends Pipeable.Pipeable, Equal.Equal {
+    readonly [ResultTypeId]: ResultTypeId
+}
+
+export const ResultPrototype: ResultPrototype = Object.freeze({
     ...Pipeable.Prototype,
     [ResultTypeId]: ResultTypeId,
 
@@ -95,7 +96,7 @@ const ResultPrototype = Object.freeze({
             Hash.cached(this),
         )
     },
-} as const satisfies Result.Prototype)
+} as const)
 
 
 export const isResult = (u: unknown): u is Result<unknown, unknown, unknown> => Predicate.hasProperty(u, ResultTypeId)
@@ -162,52 +163,40 @@ export const toExit: {
 }
 
 
-export interface State<A, E = never, P = never> {
-    readonly get: Effect.Effect<Result<A, E, P>>
-    readonly set: (v: Result<A, E, P>) => Effect.Effect<void>
-}
-
-export const State = <A, E = never, P = never>(): Context.Tag<State<A, E, P>, State<A, E, P>> => Context.GenericTag("@effect-fc/Result/State")
-
 export interface Progress<P = never> {
-    readonly update: <E, R>(
+    readonly progress: Lens.Lens<P, PreviousResultNotRunningNorRefreshing, never, never, never>
-        f: (previous: P) => Effect.Effect<P, E, R>
-    ) => Effect.Effect<void, PreviousResultNotRunningNorRefreshing | E, R>
 }
+export const Progress = <P = never>(): Context.Tag<Progress<P>, Progress<P>> => Context.GenericTag("@effect-fc/Result/Progress")
 
 export class PreviousResultNotRunningNorRefreshing extends Data.TaggedError("@effect-fc/Result/PreviousResultNotRunningNorRefreshing")<{
     readonly previous: Result<unknown, unknown, unknown>
 }> {}
 
-export const Progress = <P = never>(): Context.Tag<Progress<P>, Progress<P>> => Context.GenericTag("@effect-fc/Result/Progress")
+export const makeProgressLayer = <A, E, P = never>(
-
+    state: Lens.Lens<Result<A, E, P>, never, never, never, never>
-export const makeProgressLayer = <A, E, P = never>(): Layer.Layer<
+): Layer.Layer<Progress<P> | Progress<never>, never, never> => Layer.succeed(
-    Progress<P>,
+    Progress<P>() as Context.Tag<Progress<P> | Progress<never>, Progress<P> | Progress<never>>,
-    never,
+    {
-    State<A, E, P>
+        progress: state.pipe(
-> => Layer.effect(Progress<P>(), Effect.gen(function*() {
+            Lens.mapEffect(
-    const state = yield* State<A, E, P>()
+                a => (isRunning(a) || hasRefreshingFlag(a))
-
+                    ? Effect.succeed(a)
-    return {
+                    : Effect.fail(new PreviousResultNotRunningNorRefreshing({ previous: a })),
-        update: <FE, FR>(f: (previous: P) => Effect.Effect<P, FE, FR>) => Effect.Do.pipe(
+                (_, b) => Effect.succeed(b),
-            Effect.bind("previous", () => Effect.andThen(state.get, previous =>
-                (isRunning(previous) || hasRefreshingFlag(previous))
-                    ? Effect.succeed(previous)
-                    : Effect.fail(new PreviousResultNotRunningNorRefreshing({ previous })),
-            )),
-            Effect.bind("progress", ({ previous }) => f(previous.progress)),
-            Effect.let("next", ({ previous, progress }) => isRunning(previous)
-                ? running(progress)
-                : refreshing(previous, progress) as Final<A, E, P> & Refreshing<P>
             ),
-            Effect.andThen(({ next }) => state.set(next)),
+            Lens.map(
+                a => a.progress,
+                (a, b) => isRunning(a)
+                    ? running(b)
+                    : refreshing(a, b) as Final<A, E, P> & Refreshing<P>,
             ),
-    }
+        )
-}))
+    },
+)
 
 
 export namespace unsafeForkEffect {
-    export type OutputContext<A, E, R, P> = Exclude<R, State<A, E, P> | Progress<P> | Progress<never>>
+    export type OutputContext<R, P> = Exclude<R, Progress<P> | Progress<never>>
 
     export interface Options<A, E, P> {
         readonly initial?: Initial | Final<A, E, P>
@@ -215,55 +204,56 @@ export namespace unsafeForkEffect {
     }
 }
 
-export const unsafeForkEffect = <A, E, R, P = never>(
+export const unsafeForkEffect = Effect.fnUntraced(function* <A, E, R, P = never>(
     effect: Effect.Effect<A, E, R>,
     options?: unsafeForkEffect.Options<NoInfer<A>, NoInfer<E>, P>,
-): Effect.Effect<
+): Effect.fn.Return<
     readonly [result: Subscribable.Subscribable<Result<A, E, P>, never, never>, fiber: Fiber.Fiber<A, E>],
     never,
-    Scope.Scope | unsafeForkEffect.OutputContext<A, E, R, P>
+    Scope.Scope | unsafeForkEffect.OutputContext<R, P>
-> => Effect.Do.pipe(
+> {
-    Effect.bind("ref", () => Ref.make(options?.initial ?? initial<A, E, P>())),
+    const ref = yield* SynchronizedRef.make<Result<A, E, P>>(options?.initial ?? initial<A, E, P>())
-    Effect.bind("pubsub", () => PubSub.unbounded<Result<A, E, P>>()),
+    const pubsub = yield* PubSub.unbounded<Result<A, E, P>>()
-    Effect.bind("fiber", ({ ref, pubsub }) => Effect.forkScoped(State<A, E, P>().pipe(
+
-        Effect.andThen(state => state.set(
+    const state = Lens.make<Result<A, E, P>, never, never, never, never>({
-            (isFinal(options?.initial) && hasWillRefreshFlag(options?.initial))
+        get get() { return Ref.get(ref) },
-                ? refreshing(options.initial, options?.initialProgress) as Result<A, E, P>
+        get changes() {
-                : running(options?.initialProgress)
+            return Stream.unwrapScoped(Effect.map(
-        ).pipe(
-            Effect.andThen(effect),
-            Effect.onExit(exit => Effect.andThen(
-                state.set(fromExit(exit)),
-                Effect.forkScoped(PubSub.shutdown(pubsub)),
-            )),
-        )),
-        Effect.provide(Layer.empty.pipe(
-            Layer.provideMerge(makeProgressLayer<A, E, P>()),
-            Layer.provideMerge(Layer.succeed(State<A, E, P>(), {
-                get: Ref.get(ref),
-                set: v => Effect.andThen(Ref.set(ref, v), PubSub.publish(pubsub, v))
-            })),
-        )),
-    ))),
-    Effect.map(({ ref, pubsub, fiber }) => [
-        Subscribable.make({
-            get: Ref.get(ref),
-            changes: Stream.unwrapScoped(Effect.map(
                 Effect.all([Ref.get(ref), Stream.fromPubSub(pubsub, { scoped: true })]),
                 ([latest, stream]) => Stream.concat(Stream.make(latest), stream),
+            ))
+        },
+        modify: f => Ref.get(ref).pipe(
+            Effect.flatMap(f),
+            Effect.flatMap(([b, a]) => Ref.set(ref, a).pipe(
+                Effect.as(b),
+                Effect.zipLeft(PubSub.publish(pubsub, a))
             )),
-        }),
+        ),
-        fiber,
+    })
-    ]),
+
-) as Effect.Effect<
+    const fiber = yield* Effect.gen(function*() {
-    readonly [result: Subscribable.Subscribable<Result<A, E, P>, never, never>, fiber: Fiber.Fiber<A, E>],
+        yield* Lens.set(
-    never,
+            state,
-    Scope.Scope | unsafeForkEffect.OutputContext<A, E, R, P>
+            (isFinal(options?.initial) && hasWillRefreshFlag(options?.initial))
->
+                ? refreshing(options.initial, options?.initialProgress) as Result<A, E, P>
+                : running(options?.initialProgress),
+        )
+        return yield* Effect.onExit(effect, exit => Effect.andThen(
+            Lens.set(state, fromExit(exit)),
+            Effect.forkScoped(PubSub.shutdown(pubsub)),
+        ))
+    }).pipe(
+        Effect.forkScoped,
+        Effect.provide(makeProgressLayer(state)),
+    )
+
+    return [state, fiber] as const
+})
 
 export namespace forkEffect {
     export type InputContext<R, P> = R extends Progress<infer X> ? [X] extends [P] ? R : never : R
-    export type OutputContext<A, E, R, P> = unsafeForkEffect.OutputContext<A, E, R, P>
+    export type OutputContext<R, P> = unsafeForkEffect.OutputContext<R, P>
     export interface Options<A, E, P> extends unsafeForkEffect.Options<A, E, P> {}
 }
 
@@ -274,6 +264,6 @@ export const forkEffect: {
     ): Effect.Effect<
         readonly [result: Subscribable.Subscribable<Result<A, E, P>, never, never>, fiber: Fiber.Fiber<A, E>],
         never,
-        Scope.Scope | forkEffect.OutputContext<A, E, R, P>
+        Scope.Scope | forkEffect.OutputContext<R, P>
     >
 } = unsafeForkEffect

packages/effect-fc/src/SetStateAction.ts

@@ -3,8 +3,8 @@ import type * as React from "react"
 
 
 export const value: {
-    <S>(prevState: S): (self: React.SetStateAction<S>) => S
     <S>(self: React.SetStateAction<S>, prevState: S): S
+    <S>(prevState: S): (self: React.SetStateAction<S>) => S
 } = Function.dual(2, <S>(self: React.SetStateAction<S>, prevState: S): S =>
     typeof self === "function"
         ? (self as (prevState: S) => S)(prevState)

packages/effect-fc/src/Subscribable.ts

@@ -1,8 +1,11 @@
-import { Effect, Equivalence, Stream, Subscribable } from "effect"
+import { Effect, Equivalence, Stream } from "effect"
+import { Subscribable } from "effect-lens"
 import * as React from "react"
 import * as Component from "./Component.js"
 
 
+export * from "effect-lens/Subscribable"
+
 export const zipLatestAll = <const T extends readonly Subscribable.Subscribable<any, any, any>[]>(
     ...elements: T
 ): Subscribable.Subscribable<
@@ -48,5 +51,3 @@ export const useSubscribables = Effect.fnUntraced(function* <const T extends rea
 
     return reactStateValue as any
 })
-
-export * from "effect/Subscribable"

packages/effect-fc/src/SubscriptionSubRef.test.ts

@@ -0,0 +1,183 @@
+import { describe, expect, test } from "bun:test"
+import { Chunk, Effect, Ref, SubscriptionRef } from "effect"
+import * as SubscriptionSubRef from "./SubscriptionSubRef.js"
+
+
+describe("SubscriptionSubRef with array refs", () => {
+    test("creates a subref for a single array element using path", async () => {
+        const value = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([{ name: "alice" }, { name: "bob" }, { name: "charlie" }]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [1, "name"])
+                    return subref.get
+                },
+            ),
+        )
+
+        expect(value).toBe("bob")
+    })
+
+    test("modifies a single array element via subref", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([{ name: "alice" }, { name: "bob" }, { name: "charlie" }]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [1, "name"])
+                    return Effect.flatMap(
+                        Ref.set(subref, "bob-updated"),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(result).toEqual([{ name: "alice" }, { name: "bob-updated" }, { name: "charlie" }])
+    })
+
+    test("modifies array element at index 0", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([10, 20, 30]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [0])
+                    return Effect.flatMap(
+                        Ref.set(subref, 99),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(result).toEqual([99, 20, 30])
+    })
+
+    test("modifies array element at last index", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make(["a", "b", "c"]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [2])
+                    return Effect.flatMap(
+                        Ref.set(subref, "z"),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(result).toEqual(["a", "b", "z"])
+    })
+
+    test("modifies nested array element", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([[1, 2], [3, 4], [5, 6]]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [1, 0])
+                    return Effect.flatMap(
+                        Ref.set(subref, 99),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(result).toEqual([[1, 2], [99, 4], [5, 6]])
+    })
+
+    test("uses modifyEffect to transform array element", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([{ count: 1 }, { count: 2 }, { count: 3 }]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [1, "count"])
+                    return Effect.flatMap(
+                        Ref.update(subref, count => count + 100),
+                        () => Effect.map(Ref.get(parent), parentValue => ({ result: 102, parentValue })),
+                    )
+                },
+            ),
+        )
+
+        expect(result.result).toBe(102) // count + 100
+        expect(result.parentValue).toEqual([{ count: 1 }, { count: 102 }, { count: 3 }]) // count + 100
+    })
+
+    test("uses modify to transform array element", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([10, 20, 30]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [1])
+                    return Effect.flatMap(
+                        Ref.update(subref, x => x + 5),
+                        () => Effect.map(Ref.get(parent), parentValue => ({ result: 25, parentValue })),
+                    )
+                },
+            ),
+        )
+
+        expect(result.result).toBe(25) // 20 + 5
+        expect(result.parentValue).toEqual([10, 25, 30]) // 20 + 5
+    })
+
+    test("makeFromChunkIndex modifies chunk element", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make(Chunk.make(100, 200, 300)),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromChunkIndex(parent, 1)
+                    return Effect.flatMap(
+                        Ref.set(subref, 999),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(Chunk.toReadonlyArray(result)).toEqual([100, 999, 300])
+    })
+
+    test("makeFromGetSet with custom getter/setter for array element", async () => {
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make([{ id: 1, value: "a" }, { id: 2, value: "b" }]),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromGetSet(parent, {
+                        get: arr => arr[0].value,
+                        set: (arr, newValue) => [
+                            { ...arr[0], value: newValue },
+                            ...arr.slice(1),
+                        ],
+                    })
+                    return Effect.flatMap(
+                        Ref.set(subref, "updated"),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(result).toEqual([{ id: 1, value: "updated" }, { id: 2, value: "b" }])
+    })
+
+    test("does not mutate original array when modifying via subref", async () => {
+        const original = [{ name: "alice" }, { name: "bob" }]
+        const result = await Effect.runPromise(
+            Effect.flatMap(
+                SubscriptionRef.make(original),
+                parent => {
+                    const subref = SubscriptionSubRef.makeFromPath(parent, [0, "name"])
+                    return Effect.flatMap(
+                        Ref.set(subref, "alice-updated"),
+                        () => Ref.get(parent),
+                    )
+                },
+            ),
+        )
+
+        expect(original).toEqual([{ name: "alice" }, { name: "bob" }]) // original unchanged
+        expect(result).toEqual([{ name: "alice-updated" }, { name: "bob" }]) // new value in ref
+    })
+})

packages/effect-fc/src/index.ts

@@ -2,6 +2,7 @@ export * as Async from "./Async.js"
 export * as Component from "./Component.js"
 export * as ErrorObserver from "./ErrorObserver.js"
 export * as Form from "./Form.js"
+export * as Lens from "./Lens.js"
 export * as Memoized from "./Memoized.js"
 export * as Mutation from "./Mutation.js"
 export * as PropertyPath from "./PropertyPath.js"

packages/effect-fc/tsconfig.json

@@ -25,6 +25,7 @@
     "noPropertyAccessFromIndexSignature": false,
 
     // Build
+    "rootDir": "./src",
     "outDir": "./dist",
     "declaration": true,
     "sourceMap": true,
@@ -34,5 +35,6 @@
     ]
   },
 
-  "include": ["./src"]
+  "include": ["./src"],
+  "exclude": ["**/*.test.ts", "**/*.spec.ts"]
 }

packages/example/package.json

@@ -13,30 +13,30 @@
     "clean:modules": "rm -rf node_modules"
   },
   "devDependencies": {
-    "@tanstack/react-router": "^1.154.12",
+    "@tanstack/react-router": "^1.168.3",
-    "@tanstack/react-router-devtools": "^1.154.12",
+    "@tanstack/react-router-devtools": "^1.166.11",
-    "@tanstack/router-plugin": "^1.154.12",
+    "@tanstack/router-plugin": "^1.167.4",
-    "@types/react": "^19.2.9",
+    "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
-    "@vitejs/plugin-react": "^5.1.2",
+    "@vitejs/plugin-react": "^6.0.1",
-    "globals": "^17.0.0",
+    "globals": "^17.4.0",
-    "react": "^19.2.3",
+    "react": "^19.2.4",
-    "react-dom": "^19.2.3",
+    "react-dom": "^19.2.4",
-    "type-fest": "^5.4.1",
+    "type-fest": "^5.5.0",
-    "vite": "^7.3.1"
+    "vite": "^8.0.2"
   },
   "dependencies": {
-    "@effect/platform": "^0.94.2",
+    "@effect/platform": "^0.96.0",
-    "@effect/platform-browser": "^0.74.0",
+    "@effect/platform-browser": "^0.76.0",
-    "@radix-ui/themes": "^3.2.1",
+    "@radix-ui/themes": "^3.3.0",
     "@typed/id": "^0.17.2",
-    "effect": "^3.19.15",
+    "effect": "^3.21.0",
     "effect-fc": "workspace:*",
-    "react-icons": "^5.5.0"
+    "react-icons": "^5.6.0"
   },
   "overrides": {
-    "@types/react": "^19.2.9",
+    "@types/react": "^19.2.14",
-    "effect": "^3.19.15",
+    "effect": "^3.21.0",
-    "react": "^19.2.3"
+    "react": "^19.2.4"
   }
 }

packages/example/src/lib/form/TextFieldFormInputView.tsx

@@ -1,24 +1,22 @@
 import { Callout, Flex, Spinner, TextField } from "@radix-ui/themes"
-import { Array, Option } from "effect"
+import { Array, Option, Struct } from "effect"
 import { Component, Form, Subscribable } from "effect-fc"
 
 
 export declare namespace TextFieldFormInputView {
-    export interface Props
+    export interface Props extends Omit<TextField.RootProps, "form">, Form.useInput.Options {
-    extends TextField.RootProps, Form.useInput.Options {
+        readonly form: Form.Form<readonly PropertyKey[], any, string>
-        readonly field: Form.FormField<any, string>
     }
 }
 
-
 export class TextFieldFormInputView extends Component.make("TextFieldFormInputView")(function*(
     props: TextFieldFormInputView.Props
 ) {
-    const input = yield* Form.useInput(props.field, props)
+    const input = yield* Form.useInput(props.form, props)
     const [issues, isValidating, isSubmitting] = yield* Subscribable.useSubscribables([
-        props.field.issues,
+        props.form.issues,
-        props.field.isValidating,
+        props.form.isValidating,
-        props.field.isSubmitting,
+        props.form.isSubmitting,
     ])
 
     return (
@@ -27,7 +25,7 @@ export class TextFieldFormInputView extends Component.make("TextFieldFormInputVi
                 value={input.value}
                 onChange={e => input.setValue(e.target.value)}
                 disabled={isSubmitting}
-                {...props}
+                {...Struct.omit(props, "form")}
             >
                 {isValidating &&
                     <TextField.Slot side="right">

packages/example/src/lib/form/TextFieldOptionalFormInputView.tsx

@@ -4,21 +4,19 @@ import { Component, Form, Subscribable } from "effect-fc"
 
 
 export declare namespace TextFieldOptionalFormInputView {
-    export interface Props
+    export interface Props extends Omit<TextField.RootProps, "form" | "defaultValue">, Form.useOptionalInput.Options<string> {
-    extends Omit<TextField.RootProps, "defaultValue">, Form.useOptionalInput.Options<string> {
+        readonly form: Form.Form<readonly PropertyKey[], any, Option.Option<string>>
-        readonly field: Form.FormField<any, Option.Option<string>>
     }
 }
 
-
 export class TextFieldOptionalFormInputView extends Component.make("TextFieldOptionalFormInputView")(function*(
     props: TextFieldOptionalFormInputView.Props
 ) {
-    const input = yield* Form.useOptionalInput(props.field, props)
+    const input = yield* Form.useOptionalInput(props.form, props)
     const [issues, isValidating, isSubmitting] = yield* Subscribable.useSubscribables([
-        props.field.issues,
+        props.form.issues,
-        props.field.isValidating,
+        props.form.isValidating,
-        props.field.isSubmitting,
+        props.form.isSubmitting,
     ])
 
     return (
@@ -27,7 +25,7 @@ export class TextFieldOptionalFormInputView extends Component.make("TextFieldOpt
                 value={input.value}
                 onChange={e => input.setValue(e.target.value)}
                 disabled={!input.enabled || isSubmitting}
-                {...Struct.omit(props, "defaultValue")}
+                {...Struct.omit(props, "form", "defaultValue")}
             >
                 <TextField.Slot side="left">
                     <Switch

packages/example/src/routes/form.tsx

@@ -1,11 +1,11 @@
-import { Button, Container, Flex, Text } from "@radix-ui/themes"
-import { createFileRoute } from "@tanstack/react-router"
-import { Console, Effect, Match, Option, ParseResult, Schema } from "effect"
-import { Component, Form, Subscribable } from "effect-fc"
 import { TextFieldFormInputView } from "@/lib/form/TextFieldFormInputView"
 import { TextFieldOptionalFormInputView } from "@/lib/form/TextFieldOptionalFormInputView"
 import { DateTimeUtcFromZonedInput } from "@/lib/schema"
 import { runtime } from "@/runtime"
+import { Button, Container, Flex, Text } from "@radix-ui/themes"
+import { createFileRoute } from "@tanstack/react-router"
+import { Console, Effect, Match, Option, ParseResult, Schema } from "effect"
+import { Component, Form, Subscribable } from "effect-fc"
 
 
 const email = Schema.pattern<typeof Schema.String>(
@@ -40,7 +40,8 @@ const RegisterFormSubmitSchema = Schema.Struct({
 })
 
 class RegisterFormService extends Effect.Service<RegisterFormService>()("RegisterFormService", {
-    scoped: Form.service({
+    scoped: Effect.gen(function*() {
+        const form = yield* Form.service({
             schema: RegisterFormSchema.pipe(
                 Schema.compose(
                     Schema.transformOrFail(
@@ -59,15 +60,22 @@ class RegisterFormService extends Effect.Service<RegisterFormService>()("Registe
                 yield* Effect.sleep("500 millis")
                 return yield* Schema.decode(RegisterFormSubmitSchema)(value)
             }),
-        debounce: "500 millis",
+        })
+
+        return {
+            form,
+            emailField: Form.focusObjectField(form, "email"),
+            passwordField: Form.focusObjectField(form, "password"),
+            birthField: Form.focusObjectField(form, "birth"),
+        } as const
     })
 }) {}
 
 class RegisterFormView extends Component.make("RegisterFormView")(function*() {
     const form = yield* RegisterFormService
     const [canSubmit, submitResult] = yield* Subscribable.useSubscribables([
-        form.canSubmit,
+        form.form.canSubmit,
-        form.mutation.result,
+        form.form.mutation.result,
     ])
 
     const runPromise = yield* Component.useRunPromise()
@@ -84,20 +92,22 @@ class RegisterFormView extends Component.make("RegisterFormView")(function*() {
         <Container width="300">
             <form onSubmit={e => {
                 e.preventDefault()
-                void runPromise(form.submit)
+                void runPromise(form.form.submit)
             }}>
                 <Flex direction="column" gap="2">
                     <TextFieldFormInput
-                        field={yield* form.field(["email"])}
+                        form={form.emailField}
+                        debounce="250 millis"
                     />
 
                     <TextFieldFormInput
-                        field={yield* form.field(["password"])}
+                        form={form.passwordField}
+                        debounce="250 millis"
                     />
 
                     <TextFieldOptionalFormInput
                         type="datetime-local"
-                        field={yield* form.field(["birth"])}
+                        form={form.birthField}
                         defaultValue=""
                     />
 

packages/example/src/todo/TodoView.tsx

@@ -1,13 +1,13 @@
-import { Box, Button, Flex, IconButton } from "@radix-ui/themes"
-import { GetRandomValues, makeUuid4 } from "@typed/id"
-import { Chunk, type DateTime, Effect, Match, Option, Ref, Schema, Stream } from "effect"
-import { Component, Form, Subscribable } from "effect-fc"
-import { FaArrowDown, FaArrowUp } from "react-icons/fa"
-import { FaDeleteLeft } from "react-icons/fa6"
 import * as Domain from "@/domain"
 import { TextFieldFormInputView } from "@/lib/form/TextFieldFormInputView"
 import { TextFieldOptionalFormInputView } from "@/lib/form/TextFieldOptionalFormInputView"
 import { DateTimeUtcFromZonedInput } from "@/lib/schema"
+import { Box, Button, Flex, IconButton } from "@radix-ui/themes"
+import { GetRandomValues, makeUuid4 } from "@typed/id"
+import { Chunk, type DateTime, Effect, Match, Option, Ref, Schema, Stream } from "effect"
+import { Component, Form, Lens, Subscribable } from "effect-fc"
+import { FaArrowDown, FaArrowUp } from "react-icons/fa"
+import { FaDeleteLeft } from "react-icons/fa6"
 import { TodosState } from "./TodosState"
 
 
@@ -59,20 +59,19 @@ export class TodoView extends Component.make("TodoView")(function*(props: TodoPr
                 Match.tag("new", () => Ref.update(state.ref, Chunk.prepend(todo)).pipe(
                     Effect.andThen(makeTodo),
                     Effect.andThen(Schema.encode(TodoFormSchema)),
-                    Effect.andThen(v => Ref.set(form.encodedValue, v)),
+                    Effect.andThen(v => Lens.set(form.encodedValue, v)),
                 )),
                 Match.tag("edit", ({ id }) => Ref.set(state.getElementRef(id), todo)),
                 Match.exhaustive,
             ),
             autosubmit: props._tag === "edit",
-            debounce: "250 millis",
         })
 
         return [
             indexRef,
             form,
-            yield* form.field(["content"]),
+            Form.focusObjectField(form, "content"),
-            yield* form.field(["completedAt"]),
+            Form.focusObjectField(form, "completedAt"),
         ] as const
     }), [props._tag, props._tag === "edit" ? props.id : undefined])
 
@@ -92,11 +91,14 @@ export class TodoView extends Component.make("TodoView")(function*(props: TodoPr
         <Flex direction="row" align="center" gap="2">
             <Box flexGrow="1">
                 <Flex direction="column" align="stretch" gap="2">
-                    <TextFieldFormInput field={contentField} />
+                    <TextFieldFormInput
+                        form={contentField}
+                        debounce="250 millis"
+                    />
 
                     <Flex direction="row" justify="center" align="center" gap="2">
                         <TextFieldOptionalFormInput
-                            field={completedAtField}
+                            form={completedAtField}
                             type="datetime-local"
                             defaultValue=""
                         />