Update vitest monorepo to v4

Co-authored-by: Julien Valverdé <julien.valverde@mailo.com>
Reviewed-on: #50

.gitea/workflows/lint.yaml

@@ -9,7 +9,7 @@ jobs:
       - name: Setup Bun
         uses: oven-sh/setup-bun@v2
       - name: Clone repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install dependencies
         run: bun install --frozen-lockfile
       - name: Lint TypeScript

.gitea/workflows/publish.yaml

@@ -12,7 +12,7 @@ jobs:
       - name: Setup Bun
         uses: oven-sh/setup-bun@v2
       - name: Clone repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install dependencies
         run: bun install --frozen-lockfile
       - name: Lint TypeScript

.gitea/workflows/test-build.yaml

@@ -12,9 +12,9 @@ jobs:
       - name: Setup Node
         uses: actions/setup-node@v6
         with:
-          node-version: "22"
+          node-version: "24"
       - name: Clone repo
-        uses: actions/checkout@v5
+        uses: actions/checkout@v6
       - name: Install dependencies
         run: bun install --frozen-lockfile
       - name: Lint TypeScript

README.md

@@ -1,6 +1,6 @@
 # Effect FC Monorepo
 
-[Effect-TS](https://effect.website/) integration for React 19+ that allows you to write function components using Effect generators.
+[Effect-TS](https://effect.website/) integration for React 19.2+ that allows you to write function components using Effect generators.
 
 This monorepo contains:
 - [The `effect-fc` library](packages/effect-fc)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@effect-fc/monorepo",
-  "packageManager": "bun@1.2.23",
+  "packageManager": "bun@1.3.14",
   "private": true,
   "workspaces": [
     "./packages/*"
@@ -15,12 +15,12 @@
     "clean:modules": "turbo clean:modules && rm -rf node_modules"
   },
   "devDependencies": {
-    "@biomejs/biome": "^2.2.5",
+    "@biomejs/biome": "^2.4.16",
-    "@effect/language-service": "^0.48.0",
+    "@effect/language-service": "^0.86.2",
-    "@types/bun": "^1.2.23",
+    "@types/bun": "^1.3.14",
-    "npm-check-updates": "^19.0.0",
+    "npm-check-updates": "^22.2.1",
     "npm-sort": "^0.0.4",
-    "turbo": "^2.5.8",
+    "turbo": "^2.9.16",
-    "typescript": "^5.9.3"
+    "typescript": "^6.0.3"
   }
 }

packages/docs/.gitignore

@@ -0,0 +1,20 @@
+# Dependencies
+/node_modules
+
+# Production
+/build
+
+# Generated files
+.docusaurus
+.cache-loader
+
+# Misc
+.DS_Store
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*

packages/docs/README.md

@@ -0,0 +1,17 @@
+# effect-fc Docs
+
+The documentation site is built with Docusaurus.
+
+## Local Development
+
+```bash
+bun run --cwd packages/docs start
+```
+
+## Build
+
+```bash
+bun run --cwd packages/docs build
+```
+
+The static site is written to `packages/docs/build`.

packages/docs/biome.json

@@ -0,0 +1,8 @@
+{
+  "$schema": "https://biomejs.dev/schemas/latest/schema.json",
+  "root": false,
+  "extends": "//",
+  "files": {
+    "includes": ["./src/**"]
+  }
+}

packages/docs/docs/getting-started.md

@@ -0,0 +1,208 @@
+---
+sidebar_position: 1
+title: Getting Started
+---
+
+# Getting Started
+
+`effect-fc` lets React components be written as Effect programs. Inside a
+component body you can yield services, run Effects, subscribe to Effect-powered
+state, and still export a normal React function component at the edge of your
+app.
+
+This guide starts with the smallest useful setup:
+
+1. Install `effect-fc` with its peer dependencies.
+2. Create a React runtime from an Effect `Layer`.
+3. Wrap your React app with `ReactRuntime.Provider`.
+4. Write a component with `Component.make`.
+5. Convert it to a React component with `Component.withRuntime`.
+
+## Install
+
+Install `effect-fc` alongside `effect` and React 19.2 or newer:
+
+```bash npm2yarn
+npm install effect-fc effect react react-dom
+```
+
+If your project uses TypeScript, also install React's type packages:
+
+```bash npm2yarn
+npm install --save-dev @types/react @types/react-dom
+```
+
+## Create A Runtime
+
+An Effect-FC app needs an Effect runtime. Build one from the services your UI
+needs, then share it with React through `ReactRuntime.Provider`.
+
+For an empty app, `Layer.empty` is enough:
+
+```tsx title="src/runtime.ts"
+import { Layer } from "effect"
+import { ReactRuntime } from "effect-fc"
+
+export const runtime = ReactRuntime.make(Layer.empty)
+```
+
+As your app grows, add services to the layer:
+
+```tsx title="src/runtime.ts"
+import { FetchHttpClient } from "@effect/platform"
+import { Layer } from "effect"
+import { ReactRuntime } from "effect-fc"
+
+const AppLive = Layer.empty.pipe(
+  Layer.provideMerge(FetchHttpClient.layer),
+)
+
+export const runtime = ReactRuntime.make(AppLive)
+```
+
+## Provide The Runtime
+
+At the React root, wrap your app with `ReactRuntime.Provider`:
+
+```tsx title="src/main.tsx"
+import { StrictMode } from "react"
+import { createRoot } from "react-dom/client"
+import { ReactRuntime } from "effect-fc"
+import { App } from "./App"
+import { runtime } from "./runtime"
+
+createRoot(document.getElementById("root")!).render(
+  <StrictMode>
+    <ReactRuntime.Provider runtime={runtime}>
+      <App />
+    </ReactRuntime.Provider>
+  </StrictMode>,
+)
+```
+
+`ReactRuntime.Provider` also works with routers. Keep it above your router
+provider so route components can be converted with the same runtime context.
+
+## Write Your First Component
+
+Use `Component.make` when you want automatic tracing spans, or
+`Component.makeUntraced` when you only want the component behavior.
+
+```tsx title="src/Hello.tsx"
+import { Effect } from "effect"
+import { Component } from "effect-fc"
+import { runtime } from "./runtime"
+
+const HelloEffect = Component.make("HelloEffect")(function* (props: {
+  readonly name: string
+}) {
+  const message = yield* Effect.succeed(`Hello, ${props.name}`)
+
+  return <h1>{message}</h1>
+})
+
+export const Hello = HelloEffect.pipe(
+  Component.withRuntime(runtime.context),
+)
+```
+
+`Hello` is now a regular React component:
+
+```tsx title="src/App.tsx"
+import { Hello } from "./Hello"
+
+export function App() {
+  return <Hello name="Effect" />
+}
+```
+
+## Use Services
+
+Components can yield Effect services directly. Define services with Effect,
+provide them in your runtime layer, then consume them from the component body.
+
+```ts title="src/services.ts"
+import { Effect } from "effect"
+
+export class GreetingService extends Effect.Service<GreetingService>()(
+  "GreetingService",
+  {
+    succeed: {
+      greet: (name: string) => `Welcome, ${name}`,
+    },
+  },
+) {}
+```
+
+Provide the service in your runtime:
+
+```tsx title="src/runtime.ts"
+import { Layer } from "effect"
+import { ReactRuntime } from "effect-fc"
+import { GreetingService } from "./services"
+
+const AppLive = Layer.empty.pipe(
+  Layer.provideMerge(GreetingService.Default),
+)
+
+export const runtime = ReactRuntime.make(AppLive)
+```
+
+Then read it inside a component:
+
+```tsx title="src/Greeting.tsx"
+import { Component } from "effect-fc"
+import { runtime } from "./runtime"
+import { GreetingService } from "./services"
+
+const GreetingEffect = Component.make("Greeting")(function* (props: {
+  readonly name: string
+}) {
+  const greeting = yield* GreetingService
+
+  return <p>{greeting.greet(props.name)}</p>
+})
+
+export const Greeting = GreetingEffect.pipe(
+  Component.withRuntime(runtime.context),
+)
+```
+
+## Mount And Cleanup Effects
+
+Use `Component.useOnMount` for scoped work that should start when the component
+mounts and finalize when it unmounts.
+
+```tsx
+import { Console, Effect } from "effect"
+import { Component } from "effect-fc"
+
+const Mounted = Component.make("Mounted")(function* () {
+  yield* Component.useOnMount(() =>
+    Effect.gen(function* () {
+      yield* Console.log("Mounted")
+      yield* Effect.addFinalizer(() => Console.log("Unmounted"))
+    }),
+  )
+
+  return <p>Open the console, then unmount me.</p>
+})
+```
+
+Finalizers are tied to the component scope, so this is the right place for
+subscriptions, resources, and other lifecycle-bound Effects.
+
+## Where To Go Next
+
+Once the runtime and component boundary are in place, the rest of the library
+builds on the same idea:
+
+- `Subscribable.useAll` reads Effect subscribables and rerenders when they
+  change.
+- `Lens` connects React state and Effect `SubscriptionRef` values.
+- `Query` and `Mutation` model async data and user-triggered operations.
+- `Form`, `SubmittableForm`, and `SynchronizedForm` help build Effect-backed
+  forms.
+
+The important pattern is small and repeatable: write Effect-FC components inside
+the runtime, then use `Component.withRuntime` at React boundaries.

packages/docs/docusaurus.config.ts

@@ -0,0 +1,128 @@
+import type * as Preset from "@docusaurus/preset-classic"
+import type { Config } from "@docusaurus/types"
+import { themes as prismThemes } from "prism-react-renderer"
+
+// This runs in Node.js - Don't use client-side code here (browser APIs, JSX...)
+
+const config: Config = {
+  title: "effect-fc",
+  tagline: "Write React function components with Effect",
+  favicon: "img/favicon.ico",
+
+  // Future flags, see https://docusaurus.io/docs/api/docusaurus-config#future
+  future: {
+    v4: true, // Improve compatibility with the upcoming Docusaurus v4
+  },
+
+  // Set the production url of your site here
+  url: "https://thiladev.github.io",
+  // Set the /<baseUrl>/ pathname under which your site is served
+  // For GitHub pages deployment, it is often '/<projectName>/'
+  baseUrl: "/effect-fc/",
+
+  // GitHub pages deployment config.
+  // If you aren't using GitHub pages, you don't need these.
+  organizationName: "Thiladev", // Usually your GitHub org/user name.
+  projectName: "effect-fc", // Usually your repo name.
+
+  onBrokenLinks: "throw",
+
+  // Even if you don't use internationalization, you can use this field to set
+  // useful metadata like html lang. For example, if your site is Chinese, you
+  // may want to replace "en" with "zh-Hans".
+  i18n: {
+    defaultLocale: "en",
+    locales: ["en"],
+  },
+
+  presets: [
+    [
+      "classic",
+      {
+        docs: {
+          sidebarPath: "./sidebars.ts",
+          editUrl:
+            "https://github.com/Thiladev/effect-fc/tree/main/packages/docs/",
+        },
+        blog: false,
+        theme: {
+          customCss: "./src/css/custom.css",
+        },
+      } satisfies Preset.Options,
+    ],
+  ],
+
+  themeConfig: {
+    // Replace with your project's social card
+    colorMode: {
+      respectPrefersColorScheme: true,
+    },
+    navbar: {
+      title: "effect-fc",
+      logo: {
+        alt: "effect-fc logo",
+        src: "img/logo.svg",
+      },
+      items: [
+        {
+          type: "docSidebar",
+          sidebarId: "docsSidebar",
+          position: "left",
+          label: "Docs",
+        },
+        {
+          href: "https://github.com/Thiladev/effect-fc",
+          label: "GitHub",
+          position: "right",
+        },
+      ],
+    },
+    footer: {
+      style: "dark",
+      links: [
+        {
+          title: "Docs",
+          items: [
+            {
+              label: "Getting Started",
+              to: "/docs/getting-started",
+            },
+          ],
+        },
+        {
+          title: "Project",
+          items: [
+            {
+              label: "GitHub",
+              href: "https://github.com/Thiladev/effect-fc",
+            },
+            {
+              label: "Example App",
+              href: "https://github.com/Thiladev/effect-fc/tree/main/packages/example",
+            },
+          ],
+        },
+        {
+          title: "Ecosystem",
+          items: [
+            {
+              label: "Effect",
+              href: "https://effect.website/",
+            },
+            {
+              label: "React",
+              href: "https://react.dev/",
+            },
+          ],
+        },
+      ],
+      copyright: `Copyright © ${new Date().getFullYear()} effect-fc contributors. Built with Docusaurus.`,
+    },
+    prism: {
+      theme: prismThemes.github,
+      darkTheme: prismThemes.dracula,
+    },
+  } satisfies Preset.ThemeConfig,
+}
+
+export default config

packages/docs/package.json

@@ -0,0 +1,50 @@
+{
+  "name": "docs",
+  "version": "0.0.0",
+  "private": true,
+  "scripts": {
+    "docusaurus": "docusaurus",
+    "start": "docusaurus start",
+    "build": "docusaurus build",
+    "swizzle": "docusaurus swizzle",
+    "deploy": "docusaurus deploy",
+    "clear": "docusaurus clear",
+    "serve": "docusaurus serve",
+    "write-translations": "docusaurus write-translations",
+    "write-heading-ids": "docusaurus write-heading-ids",
+    "typecheck": "tsc"
+  },
+  "dependencies": {
+    "@docusaurus/core": "3.10.1",
+    "@docusaurus/faster": "^3.10.1",
+    "@docusaurus/preset-classic": "3.10.1",
+    "@mdx-js/react": "^3.1.1",
+    "clsx": "^2.1.1",
+    "prism-react-renderer": "^2.4.1",
+    "react": "^19.2.5",
+    "react-dom": "^19.2.5"
+  },
+  "devDependencies": {
+    "@docusaurus/module-type-aliases": "3.10.1",
+    "@docusaurus/tsconfig": "3.10.1",
+    "@docusaurus/types": "3.10.1",
+    "@types/react": "^19.2.15",
+    "@types/react-dom": "^19.2.3",
+    "typescript": "~6.0.3"
+  },
+  "browserslist": {
+    "production": [
+      ">0.5%",
+      "not dead",
+      "not op_mini all"
+    ],
+    "development": [
+      "last 3 chrome version",
+      "last 3 firefox version",
+      "last 5 safari version"
+    ]
+  },
+  "engines": {
+    "node": ">=20.0"
+  }
+}

packages/docs/sidebars.ts

@@ -0,0 +1,9 @@
+import type { SidebarsConfig } from "@docusaurus/plugin-content-docs"
+
+// This runs in Node.js - Don't use client-side code here (browser APIs, JSX...)
+
+const sidebars: SidebarsConfig = {
+  docsSidebar: ["getting-started"],
+}
+
+export default sidebars

packages/docs/src/css/custom.css

@@ -0,0 +1,37 @@
+:root {
+  --ifm-color-primary: #0b6f74;
+  --ifm-color-primary-dark: #096469;
+  --ifm-color-primary-darker: #085e63;
+  --ifm-color-primary-darkest: #074d51;
+  --ifm-color-primary-light: #0d7a7f;
+  --ifm-color-primary-lighter: #0e8085;
+  --ifm-color-primary-lightest: #109096;
+  --ifm-background-color: #fffaf1;
+  --ifm-code-font-size: 95%;
+  --ifm-font-family-base:
+    "Avenir Next", "Segoe UI", "Helvetica Neue", sans-serif;
+  --docusaurus-highlighted-code-line-bg: rgba(11, 111, 116, 0.1);
+}
+
+.button--primary {
+  --ifm-button-background-color: #0b6f74;
+  --ifm-button-border-color: #0b6f74;
+}
+
+.button--secondary {
+  --ifm-button-background-color: #f4a636;
+  --ifm-button-border-color: #f4a636;
+  --ifm-button-color: #1f2526;
+}
+
+[data-theme="dark"] {
+  --ifm-color-primary: #7ad6d4;
+  --ifm-color-primary-dark: #5cccca;
+  --ifm-color-primary-darker: #4cc6c4;
+  --ifm-color-primary-darkest: #34aaa8;
+  --ifm-color-primary-light: #98e0de;
+  --ifm-color-primary-lighter: #a8e6e4;
+  --ifm-color-primary-lightest: #d5f4f3;
+  --ifm-background-color: #111c1f;
+  --docusaurus-highlighted-code-line-bg: rgba(122, 214, 212, 0.18);
+}

packages/docs/src/pages/index.module.css

@@ -0,0 +1,80 @@
+.page {
+  min-height: calc(100vh - var(--ifm-navbar-height));
+  background:
+    radial-gradient(circle at top left, rgba(11, 111, 116, 0.22), transparent 32rem),
+    radial-gradient(circle at 85% 20%, rgba(244, 166, 54, 0.18), transparent 28rem),
+    linear-gradient(135deg, #f8f4ea 0%, #eef8f7 48%, #fffaf1 100%);
+}
+
+.hero {
+  padding: 8rem 1rem 5rem;
+}
+
+.eyebrow {
+  color: #0b6f74;
+  font-size: 0.85rem;
+  font-weight: 800;
+  letter-spacing: 0.16em;
+  margin-bottom: 1.25rem;
+  text-transform: uppercase;
+}
+
+.hero h1 {
+  color: #132c2f;
+  font-size: clamp(3rem, 9vw, 6.75rem);
+  letter-spacing: -0.08em;
+  line-height: 0.9;
+  margin: 0;
+  max-width: 880px;
+}
+
+.lede {
+  color: #385256;
+  font-size: clamp(1.15rem, 2vw, 1.45rem);
+  line-height: 1.65;
+  margin: 2rem 0 0;
+  max-width: 720px;
+}
+
+.actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 1rem;
+  margin-top: 2.5rem;
+}
+
+.cards {
+  display: grid;
+  gap: 1.25rem;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  padding: 0 1rem 6rem;
+}
+
+.cards article {
+  background: rgba(255, 255, 255, 0.74);
+  border: 1px solid rgba(19, 44, 47, 0.12);
+  border-radius: 1.5rem;
+  box-shadow: 0 24px 80px rgba(19, 44, 47, 0.08);
+  padding: 1.5rem;
+}
+
+.cards h2 {
+  color: #132c2f;
+  font-size: 1.2rem;
+  margin-bottom: 0.75rem;
+}
+
+.cards p {
+  color: #486267;
+  margin: 0;
+}
+
+@media screen and (max-width: 996px) {
+  .hero {
+    padding-top: 5rem;
+  }
+
+  .cards {
+    grid-template-columns: 1fr;
+  }
+}

packages/docs/src/pages/index.tsx

@@ -0,0 +1,62 @@
+import Link from "@docusaurus/Link"
+import Layout from "@theme/Layout"
+import clsx from "clsx"
+import type { ReactNode } from "react"
+
+import styles from "./index.module.css"
+
+export default function Home(): ReactNode {
+  return (
+    <Layout
+      title="effect-fc"
+      description="Write React function components with Effect"
+    >
+      <main className={styles.page}>
+        <section className={clsx("container", styles.hero)}>
+          <p className={styles.eyebrow}>Effect for React function components</p>
+          <h1>Write components as Effect programs.</h1>
+          <p className={styles.lede}>
+            effect-fc gives React 19 components access to Effect services,
+            scopes, subscriptions, and async workflows without giving up normal
+            React boundaries.
+          </p>
+          <div className={styles.actions}>
+            <Link className="button button--primary button--lg" to="/docs/getting-started">
+              Get Started
+            </Link>
+            <Link
+              className="button button--secondary button--lg"
+              to="https://github.com/Thiladev/effect-fc"
+            >
+              GitHub
+            </Link>
+          </div>
+        </section>
+
+        <section className={clsx("container", styles.cards)}>
+          <article>
+            <h2>Generator components</h2>
+            <p>
+              Use <code>Component.make</code> to yield Effects and return JSX
+              from the same component body.
+            </p>
+          </article>
+          <article>
+            <h2>Runtime at the edge</h2>
+            <p>
+              Provide your app layer once with <code>ReactRuntime.Provider</code>
+              and convert Effect-FC components at React boundaries.
+            </p>
+          </article>
+          <article>
+            <h2>Scoped lifecycles</h2>
+            <p>
+              Tie subscriptions and resources to component scopes so finalizers
+              run when React unmounts.
+            </p>
+          </article>
+        </section>
+      </main>
+    </Layout>
+  )
+}

packages/docs/static/img/logo.svg

@@ -0,0 +1,6 @@
+<svg width="128" height="128" viewBox="0 0 128 128" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <rect width="128" height="128" rx="32" fill="#0B6F74"/>
+  <path d="M34 39H78C88.4934 39 97 47.5066 97 58C97 68.4934 88.4934 77 78 77H51V95H34V39Z" fill="#FFF9ED"/>
+  <path d="M51 55V62H78C80.2091 62 82 60.2091 82 58C82 55.7909 80.2091 55 78 55H51Z" fill="#0B6F74"/>
+  <path d="M51 77H86V95H51V77Z" fill="#F4A636"/>
+</svg>

packages/docs/tsconfig.json

@@ -0,0 +1,9 @@
+{
+  // This file is not used in compilation. It is here just for a nice editor experience.
+  "extends": "@docusaurus/tsconfig",
+  "compilerOptions": {
+    "baseUrl": ".",
+    "ignoreDeprecations": "6.0"
+  },
+  "exclude": [".docusaurus", "build"]
+}

packages/effect-fc/README.md

@@ -1,59 +1,51 @@
 # Effect FC
 
-[Effect-TS](https://effect.website/) integration for React 19+ that allows you to write function components using Effect generators.
+[Effect-TS](https://effect.website/) integration for React 19.2+ that allows you to write function components using Effect generators.
 
 This library is in early development. While it is (almost) feature complete and mostly usable, expect bugs and quirks. Things are still being ironed out, so ideas and criticisms are more than welcome.
 
 Documentation is currently being written. In the meantime, you can take a look at the `packages/example` directory.
 
 ## Peer dependencies
-- `effect` 3.15+
+- `effect` 3.19+
-- `react` & `@types/react` 19+
+- `react` & `@types/react` 19.2+
 
 ## Known issues
 - React Refresh doesn't work for Effect FC's yet. Page reload is required to view changes. Regular React components are unaffected.
 
 ## What writing components looks like
 ```typescript
-import { Component } from "effect-fc"
+export class TodosView extends Component.make("TodosView")(function*() {
-import { useOnce, useSubscribables } from "effect-fc/Hooks"
-import { Todo } from "./Todo"
-import { TodosState } from "./TodosState.service"
-
-
-export class Todos extends Component.makeUntraced("Todos")(function*() {
     const state = yield* TodosState
-    const [todos] = yield* useSubscribables(state.ref)
+    const [todos] = yield* Component.useSubscribables([state.subscriptionRef])
 
-    yield* useOnce(() => Effect.andThen(
+    yield* Component.useOnMount(() => Effect.andThen(
         Console.log("Todos mounted"),
         Effect.addFinalizer(() => Console.log("Todos unmounted")),
     ))
 
-    const TodoFC = yield* Todo
+    const Todo = yield* TodoView.use
 
     return (
         <Container>
             <Heading align="center">Todos</Heading>
 
             <Flex direction="column" align="stretch" gap="2" mt="2">
-                <TodoFC _tag="new" />
+                <Todo _tag="new" />
 
                 {Chunk.map(todos, todo =>
-                    <TodoFC key={todo.id} _tag="edit" id={todo.id} />
+                    <Todo key={todo.id} _tag="edit" id={todo.id} />
                 )}
             </Flex>
         </Container>
     )
 }) {}
 
-const TodosStateLive = TodosState.Default("todos")
+const Index = Component.make("IndexView")(function*() {
+    const context = yield* Component.useContextFromLayer(TodosState.Default)
+    const Todos = yield* Effect.provide(TodosView.use, context)
 
-const Index = Component.makeUntraced("Index")(function*() {
+    return <Todos />
-    const context = yield* useContext(TodosStateLive, { finalizerExecutionMode: "fork" })
-    const TodosFC = yield* Effect.provide(Todos, context)
-
-    return <TodosFC />
 }).pipe(
     Component.withRuntime(runtime.context)
 )

packages/effect-fc/package.json

@@ -1,7 +1,7 @@
 {
   "name": "effect-fc",
   "description": "Write React function components with Effect",
-  "version": "0.2.0",
+  "version": "0.3.0",
   "type": "module",
   "files": [
     "./README.md",
@@ -32,17 +32,24 @@
     "build": "tsc",
     "lint:tsc": "tsc --noEmit",
     "lint:biome": "biome lint",
+    "test": "vitest run",
     "pack": "npm pack",
     "clean:cache": "rm -rf .turbo tsconfig.tsbuildinfo",
     "clean:dist": "rm -rf dist",
     "clean:modules": "rm -rf node_modules"
   },
+  "devDependencies": {
+    "@effect/platform-browser": "^0.76.0",
+    "@testing-library/react": "^16.3.0",
+    "jsdom": "^26.1.0",
+    "vitest": "^4.0.0"
+  },
   "peerDependencies": {
-    "@types/react": "^19.0.0",
+    "@types/react": "^19.2.0",
-    "effect": "^3.15.0",
+    "effect": "^3.21.0",
-    "react": "^19.0.0"
+    "react": "^19.2.0"
   },
   "dependencies": {
-    "@typed/async-data": "^0.13.1"
+    "effect-lens": "^0.2.0"
   }
 }

packages/effect-fc/src/Async.ts

@@ -1,35 +1,49 @@
 /** biome-ignore-all lint/complexity/useArrowFunction: necessary for class prototypes */
-import { Effect, Function, Predicate, Runtime, Scope } from "effect"
+import { Effect, type Equivalence, Function, Predicate, Runtime, Scope } from "effect"
 import * as React from "react"
 import * as Component from "./Component.js"
 
 
-export const TypeId: unique symbol = Symbol.for("@effect-fc/Async/Async")
+export const AsyncTypeId: unique symbol = Symbol.for("@effect-fc/Async/Async")
-export type TypeId = typeof TypeId
+export type AsyncTypeId = typeof AsyncTypeId
 
-export interface Async extends Async.Options {
+
-    readonly [TypeId]: TypeId
+/**
+ * A trait for `Component`'s that allows them running asynchronous effects.
+ */
+export interface Async extends AsyncPrototype, AsyncOptions {}
+
+export interface AsyncPrototype {
+    readonly [AsyncTypeId]: AsyncTypeId
 }
 
-export namespace Async {
+/**
-    export interface Options {
+ * Configuration options for `Async` components.
+ */
+export interface AsyncOptions {
+    /**
+     * The default fallback React node to display while the async operation is pending.
+     * Used if no fallback is provided to the component when rendering.
+     */
     readonly defaultFallback?: React.ReactNode
 }
 
-    export type Props = Omit<React.SuspenseProps, "children">
+/**
-}
+ * Props for `Async` components.
+ */
+export type AsyncProps = Omit<React.SuspenseProps, "children">
 
 
-const SuspenseProto = Object.freeze({
+export const AsyncPrototype: AsyncPrototype = Object.freeze({
-    [TypeId]: TypeId,
+    [AsyncTypeId]: AsyncTypeId,
 
-    makeFunctionComponent<P extends {}, A extends React.ReactNode, E, R>(
+    asFunctionComponent<P extends {}, A extends React.ReactNode, E, R, F extends Component.Component.Signature>(
-        this: Component.Component<P, A, E, R> & Async,
+        this: Component.Component<P, A, E, R, F> & Async,
         runtimeRef: React.RefObject<Runtime.Runtime<Exclude<R, Scope.Scope>>>,
     ) {
-        const SuspenseInner = (props: { readonly promise: Promise<React.ReactNode> }) => React.use(props.promise)
+        const Inner = (props: { readonly promise: Promise<React.ReactNode> }) => React.use(props.promise)
 
-        return ({ fallback, name, ...props }: Async.Props) => {
+        return ({ fallback, name, ...props }: AsyncProps) => {
             const promise = Runtime.runPromise(runtimeRef.current)(
                 Effect.andThen(
                     Component.useScope([], this),
@@ -40,45 +54,117 @@ const SuspenseProto = Object.freeze({
             return React.createElement(
                 React.Suspense,
                 { fallback: fallback ?? this.defaultFallback, name },
-                React.createElement(SuspenseInner, { promise }),
+                React.createElement(Inner, { promise }),
             )
         }
     },
 } as const)
 
+/**
+ * An equivalence function for comparing `AsyncProps` that ignores the `fallback` property.
+ * Used by default by async components with `Memoized.memoized` applied.
+ */
+export const defaultPropsEquivalence: Equivalence.Equivalence<AsyncProps> = (
+    self: Record<string, unknown>,
+    that: Record<string, unknown>,
+) => {
+    if (self === that)
+        return true
 
-export const isAsync = (u: unknown): u is Async => Predicate.hasProperty(u, TypeId)
+    for (const key in self) {
+        if (key === "fallback")
+            continue
+        if (!(key in that) || !Object.is(self[key], that[key]))
+            return false
+    }
 
-export const async = <T extends Component.Component<any, any, any, any>>(
+    for (const key in that) {
-    self: T
+        if (key === "fallback")
+            continue
+        if (!(key in self))
+            return false
+    }
+
+    return true
+}
+
+
+export const isAsync = (u: unknown): u is Async => Predicate.hasProperty(u, AsyncTypeId)
+
+/**
+ * Converts a Component into an `Async` component that supports running asynchronous effects.
+ *
+ * Note: The component cannot have a prop named "promise" as it's reserved for internal use.
+ *
+ * @param self - The component to convert to an Async component
+ * @returns A new `Async` component with the same body, error, and context types as the input
+ *
+ * @example
+ * ```ts
+ * const MyAsyncComponent = MyComponent.pipe(
+ *   Async.async,
+ * )
+ * ```
+ */
+export const async = <T extends Component.Component.Any>(
+    self: T & (
+        "promise" extends keyof Component.Component.Props<T>
+            ? "The 'promise' prop name is restricted for Async components. Please rename the 'promise' prop to something else."
+            : T
+    )
 ): (
     & Omit<T, keyof Component.Component.AsComponent<T>>
     & Component.Component<
-        Component.Component.Props<T> & Async.Props,
+        Component.Component.Props<T> & AsyncProps,
         Component.Component.Success<T>,
         Component.Component.Error<T>,
-        Component.Component.Context<T>
+        Component.Component.Context<T>,
+        Component.Component.DefaultSignature<Component.Component.Props<T> & AsyncProps, Component.Component.Success<T>>
     >
     & Async
 ) => Object.setPrototypeOf(
-    Object.assign(function() {}, self),
+    Object.assign(function() {}, self, { propsEquivalence: defaultPropsEquivalence }),
     Object.freeze(Object.setPrototypeOf(
-        Object.assign({}, SuspenseProto),
+        Object.assign({}, AsyncPrototype),
         Object.getPrototypeOf(self),
     )),
 )
 
+/**
+ * Applies options to an Async component, returning a new Async component with the updated configuration.
+ *
+ * Supports both curried and uncurried application styles.
+ *
+ * @param self - The Async component to apply options to (in uncurried form)
+ * @param options - The options to apply to the component
+ * @returns An Async component with the applied options
+ *
+ * @example
+ * ```ts
+ * // Curried
+ * const MyAsyncComponent = MyComponent.pipe(
+ *   Async.async,
+ *   Async.withOptions({ defaultFallback: <p>Loading...</p> }),
+ * )
+ *
+ * // Uncurried
+ * const MyAsyncComponent = Async.withOptions(
+ *   Async.async(MyComponent),
+ *   { defaultFallback: <p>Loading...</p> },
+ * )
+ * ```
+ */
 export const withOptions: {
-    <T extends Component.Component<any, any, any, any> & Async>(
+    <T extends Component.Component.Any & Async>(
-        options: Partial<Async.Options>
+        options: Partial<AsyncOptions>
     ): (self: T) => T
-    <T extends Component.Component<any, any, any, any> & Async>(
+    <T extends Component.Component.Any & Async>(
         self: T,
-        options: Partial<Async.Options>,
+        options: Partial<AsyncOptions>,
     ): T
-} = Function.dual(2, <T extends Component.Component<any, any, any, any> & Async>(
+} = Function.dual(2, <T extends Component.Component.Any & Async>(
     self: T,
-    options: Partial<Async.Options>,
+    options: Partial<AsyncOptions>,
 ): T => Object.setPrototypeOf(
     Object.assign(function() {}, self, options),
     Object.getPrototypeOf(self),

packages/effect-fc/src/ErrorObserver.ts

@@ -0,0 +1,62 @@
+import { type Cause, Context, Effect, Exit, Layer, Option, Pipeable, Predicate, PubSub, type Queue, type Scope, Supervisor } from "effect"
+
+
+export const ErrorObserverTypeId: unique symbol = Symbol.for("@effect-fc/ErrorObserver/ErrorObserver")
+export type ErrorObserverTypeId = typeof ErrorObserverTypeId
+
+export interface ErrorObserver<in out E = never> extends Pipeable.Pipeable {
+    readonly [ErrorObserverTypeId]: ErrorObserverTypeId
+    handle<A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, R>
+    readonly subscribe: Effect.Effect<Queue.Dequeue<Cause.Cause<E>>, never, Scope.Scope>
+}
+
+export const ErrorObserver = <E = never>(): Context.Tag<ErrorObserver, ErrorObserver<E>> => Context.GenericTag("@effect-fc/ErrorObserver/ErrorObserver")
+
+export class ErrorObserverImpl<in out E = never>
+extends Pipeable.Class() implements ErrorObserver<E> {
+    readonly [ErrorObserverTypeId]: ErrorObserverTypeId = ErrorObserverTypeId
+    readonly subscribe: Effect.Effect<Queue.Dequeue<Cause.Cause<E>>, never, Scope.Scope>
+
+    constructor(
+        readonly pubsub: PubSub.PubSub<Cause.Cause<E>>
+    ) {
+        super()
+        this.subscribe = pubsub.subscribe
+    }
+
+    handle<A, EffE, R>(effect: Effect.Effect<A, EffE, R>): Effect.Effect<A, EffE, R> {
+        return Effect.tapErrorCause(effect, cause => PubSub.publish(this.pubsub, cause as Cause.Cause<E>))
+    }
+}
+
+export class ErrorObserverSupervisorImpl extends Supervisor.AbstractSupervisor<void> {
+    readonly value = Effect.void
+    constructor(readonly pubsub: PubSub.PubSub<Cause.Cause<never>>) {
+        super()
+    }
+
+    onEnd<A, E>(_value: Exit.Exit<A, E>): void {
+        if (Exit.isFailure(_value)) {
+            Effect.runSync(PubSub.publish(this.pubsub, _value.cause as Cause.Cause<never>))
+        }
+    }
+}
+
+
+export const isErrorObserver = (u: unknown): u is ErrorObserver<unknown> => Predicate.hasProperty(u, ErrorObserverTypeId)
+
+export const layer: Layer.Layer<ErrorObserver> = Layer.unwrapEffect(Effect.map(
+    PubSub.unbounded<Cause.Cause<never>>(),
+    pubsub => Layer.merge(
+        Supervisor.addSupervisor(new ErrorObserverSupervisorImpl(pubsub)),
+        Layer.succeed(ErrorObserver(), new ErrorObserverImpl(pubsub)),
+    ),
+))
+
+export const handle = <A, E, R>(effect: Effect.Effect<A, E, R>): Effect.Effect<A, E, R> => Effect.andThen(
+    Effect.serviceOption(ErrorObserver()),
+    Option.match({
+        onSome: observer => observer.handle(effect),
+        onNone: () => effect,
+    }),
+)

packages/effect-fc/src/Form.ts

@@ -1,299 +1,203 @@
-import * as AsyncData from "@typed/async-data"
+import { Array, type Cause, Chunk, type Duration, Effect, Equal, Function, identity, Option, type ParseResult, Pipeable, Predicate, type Scope, Stream, SubscriptionRef } from "effect"
-import { Array, Cause, Chunk, type Duration, Effect, Equal, Exit, Fiber, flow, identity, Option, ParseResult, Pipeable, Predicate, Ref, Schema, type Scope, Stream } from "effect"
+import type * as React from "react"
-import type { NoSuchElementException } from "effect/Cause"
-import * as React from "react"
 import * as Component from "./Component.js"
-import * as PropertyPath from "./PropertyPath.js"
+import * as Lens from "./Lens.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, out R = never, in out SA = void, in out SE = A, out SR = 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 schema: Schema.Schema<A, I, R>
+    readonly path: P
-    readonly onSubmit: (value: NoInfer<A>) => Effect.Effect<SA, SE, SR>
+    readonly value: Subscribable.Subscribable<Option.Option<A>, ER, never>
-    readonly autosubmit: boolean
+    readonly encodedValue: Lens.Lens<I, ER, EW, never, never>
-    readonly debounce: Option.Option<Duration.DurationInput>
+    readonly issues: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[], never, never>
-
+    readonly isValidating: Subscribable.Subscribable<boolean, ER, never>
-    readonly valueRef: SubscriptionRef.SubscriptionRef<Option.Option<A>>
+    readonly canCommit: Subscribable.Subscribable<boolean, never, never>
-    readonly encodedValueRef: SubscriptionRef.SubscriptionRef<I>
+    readonly isCommitting: Subscribable.Subscribable<boolean, never, never>
-    readonly errorRef: SubscriptionRef.SubscriptionRef<Option.Option<ParseResult.ParseError>>
-    readonly validationFiberRef: SubscriptionRef.SubscriptionRef<Option.Option<Fiber.Fiber<void, never>>>
-    readonly submitStateRef: SubscriptionRef.SubscriptionRef<AsyncData.AsyncData<SA, SE>>
-
-    readonly canSubmitSubscribable: Subscribable.Subscribable<boolean>
 }
 
-class FormImpl<in out A, in out I = A, out R = never, in out SA = void, in out SE = A, out SR = 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<A, I, R, SA, SE, SR> {
+extends Pipeable.Class() implements Form<P, A, I, ER, EW> {
     readonly [FormTypeId]: FormTypeId = FormTypeId
 
     constructor(
-        readonly schema: Schema.Schema<A, I, R>,
+        readonly path: P,
-        readonly onSubmit: (value: NoInfer<A>) => Effect.Effect<SA, SE, SR>,
+        readonly value: Subscribable.Subscribable<Option.Option<A>, ER, never>,
-        readonly autosubmit: boolean,
+        readonly encodedValue: Lens.Lens<I, ER, EW, never, never>,
-        readonly debounce: Option.Option<Duration.DurationInput>,
+        readonly issues: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[], never, never>,
-
+        readonly isValidating: Subscribable.Subscribable<boolean, never, never>,
-        readonly valueRef: SubscriptionRef.SubscriptionRef<Option.Option<A>>,
+        readonly canCommit: Subscribable.Subscribable<boolean, never, never>,
-        readonly encodedValueRef: SubscriptionRef.SubscriptionRef<I>,
+        readonly isCommitting: Subscribable.Subscribable<boolean, never, never>,
-        readonly errorRef: SubscriptionRef.SubscriptionRef<Option.Option<ParseResult.ParseError>>,
-        readonly validationFiberRef: SubscriptionRef.SubscriptionRef<Option.Option<Fiber.Fiber<void, never>>>,
-        readonly submitStateRef: SubscriptionRef.SubscriptionRef<AsyncData.AsyncData<SA, SE>>,
-
-        readonly canSubmitSubscribable: Subscribable.Subscribable<boolean>,
     ) {
         super()
     }
 }
 
-export const isForm = (u: unknown): u is Form<unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, FormTypeId)
 
-export namespace make {
+export const isForm = (u: unknown): u is Form<readonly PropertyKey[], unknown, unknown> => Predicate.hasProperty(u, FormTypeId)
-    export interface Options<in out A, in out I, in out R, in out SA = void, in out SE = A, out SR = never> {
-        readonly schema: Schema.Schema<A, I, R>
-        readonly initialEncodedValue: NoInfer<I>
-        readonly onSubmit: (
-            this: Form<NoInfer<A>, NoInfer<I>, NoInfer<R>, unknown, unknown, unknown>,
-            value: NoInfer<A>,
-        ) => Effect.Effect<SA, SE, SR>
-        readonly autosubmit?: boolean
-        readonly debounce?: Duration.DurationInput
-    }
-}
 
-export const make: {
+
-    <A, I = A, R = never, SA = void, SE = A, SR = never>(
+const filterIssuesByPath = (
-        options: make.Options<A, I, R, SA, SE, SR>
+    issues: readonly ParseResult.ArrayFormatterIssue[],
-    ): Effect.Effect<Form<A, I, R, SA, SE, SR>>
+    path: readonly PropertyKey[],
-} = Effect.fnUntraced(function* <A, I = A, R = never, SA = void, SE = A, SR = never>(
+): readonly ParseResult.ArrayFormatterIssue[] => Array.filter(issues, issue =>
-    options: make.Options<A, I, R, SA, SE, SR>
+    issue.path.length >= path.length && Array.every(path, (p, i) => p === issue.path[i])
-) {
+)
-    const valueRef = yield* SubscriptionRef.make(Option.none<A>())
+
-    const errorRef = yield* SubscriptionRef.make(Option.none<ParseResult.ParseError>())
+export const focusObjectOn: {
-    const validationFiberRef = yield* SubscriptionRef.make(Option.none<Fiber.Fiber<void, never>>())
+    <P extends readonly PropertyKey[], A extends object, I extends object, ER, EW, K extends keyof A & keyof I>(
-    const submitStateRef = yield* SubscriptionRef.make(AsyncData.noData<SA, SE>())
+        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(
-        options.schema,
+        path,
-        options.onSubmit,
+        Subscribable.mapOption(form.value, a => a[key]),
-        options.autosubmit ?? false,
+        Lens.focusObjectOn(form.encodedValue, key),
-        Option.fromNullable(options.debounce),
+        Subscribable.map(form.issues, issues => filterIssuesByPath(issues, path)),
-
+        form.isValidating,
-        valueRef,
+        form.canCommit,
-        yield* SubscriptionRef.make(options.initialEncodedValue),
+        form.isCommitting,
-        errorRef,
-        validationFiberRef,
-        submitStateRef,
-
-        Subscribable.map(
-            Subscribable.zipLatestAll(valueRef, errorRef, validationFiberRef, submitStateRef),
-            ([value, error, validationFiber, submitState]) => (
-                Option.isSome(value) &&
-                Option.isNone(error) &&
-                Option.isNone(validationFiber) &&
-                !AsyncData.isLoading(submitState)
-            ),
-        ),
     )
 })
 
-export const run = <A, I, R, SA, SE, SR>(
+export const focusArrayAt: {
-    self: Form<A, I, R, SA, SE, SR>
+    <P extends readonly PropertyKey[], A extends readonly any[], I extends readonly any[], ER, EW>(
-): Effect.Effect<void, never, Scope.Scope | R | SR> => Stream.runForEach(
+        self: Form<P, A, I, ER, EW>,
-    self.encodedValueRef.changes.pipe(
+        index: number,
-        Option.isSome(self.debounce) ? Stream.debounce(self.debounce.value) : identity
+    ): 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
 
-    encodedValue => self.validationFiberRef.pipe(
+    return new FormImpl(
-        Effect.andThen(Option.match({
+        path,
-            onSome: Fiber.interrupt,
+        Subscribable.mapOptionEffect(form.value, Array.get(index)),
-            onNone: () => Effect.void,
+        Lens.focusArrayAt(form.encodedValue, index),
-        })),
+        Subscribable.map(form.issues, issues => filterIssuesByPath(issues, path)),
-        Effect.andThen(
+        form.isValidating,
-            Effect.addFinalizer(() => Ref.set(self.validationFiberRef, Option.none())).pipe(
+        form.canCommit,
-                Effect.andThen(Schema.decode(self.schema, { errors: "all" })(encodedValue)),
+        form.isCommitting,
-                Effect.exit,
-                Effect.andThen(flow(
-                    Exit.matchEffect({
-                        onSuccess: v => Ref.set(self.valueRef, Option.some(v)).pipe(
-                            Effect.andThen(Ref.set(self.errorRef, Option.none())),
-                            Effect.as(Option.some(v)),
-                        ),
-                        onFailure: c => Chunk.findFirst(Cause.failures(c), e => e._tag === "ParseError").pipe(
-                            Option.match({
-                                onSome: e => Ref.set(self.errorRef, Option.some(e)),
-                                onNone: () => Effect.void,
-                            }),
-                            Effect.as(Option.none<A>()),
-                        ),
-                    }),
-                    Effect.uninterruptible,
-                )),
-                Effect.scoped,
-
-                Effect.andThen(value => Option.isSome(value) && self.autosubmit
-                    ? Effect.asVoid(Effect.forkScoped(submit(self)))
-                    : Effect.void
-                ),
-                Effect.forkScoped,
     )
-        ),
+})
-        Effect.andThen(fiber => Ref.set(self.validationFiberRef, Option.some(fiber)))
+
-    ),
+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.canCommit,
+        form.isCommitting,
     )
+})
 
-export const submit = <A, I, R, SA, SE, SR>(
+export const focusChunkAt: {
-    self: Form<A, I, R, SA, SE, SR>
+    <P extends readonly PropertyKey[], A, I, ER, EW>(
-): Effect.Effect<Option.Option<AsyncData.AsyncData<SA, SE>>, NoSuchElementException, SR> => Effect.whenEffect(
+        self: Form<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>,
-    self.valueRef.pipe(
+        index: number,
-        Effect.andThen(identity),
+    ): Form<readonly [...P, number], A, I, ER | Cause.NoSuchElementException, EW>
-        Effect.tap(Ref.set(self.submitStateRef, AsyncData.loading())),
+    <P extends readonly PropertyKey[], A, I, ER, EW>(
-        Effect.andThen(flow(
+        index: number,
-            self.onSubmit as (value: NoInfer<A>) => Effect.Effect<SA, SE | ParseResult.ParseError, SR>,
+    ): (self: Form<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>) => Form<readonly [...P, number], A, I, ER | Cause.NoSuchElementException, EW>
-            Effect.tapErrorTag("ParseError", e => Ref.set(self.errorRef, Option.some(e as ParseResult.ParseError))),
+} = Function.dual(2, <P extends readonly PropertyKey[], A, I, ER, EW>(
-            Effect.exit,
+    self: Form<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>,
-            Effect.map(Exit.match({
+    index: number,
-                onSuccess: a => AsyncData.success(a),
+): Form<readonly [...P, number], A, I, ER | Cause.NoSuchElementException, EW> => {
-                onFailure: e => AsyncData.failure(e as Cause.Cause<SE>),
+    const form = self as FormImpl<P, Chunk.Chunk<A>, Chunk.Chunk<I>, ER, EW>
-            })),
+    const path = [...form.path, index] as const
-            Effect.tap(v => Ref.set(self.submitStateRef, v)),
-        )),
-    ),
 
-    self.canSubmitSubscribable.get,
+    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.canCommit,
+        form.isCommitting,
     )
+})
 
-export namespace service {
-    export interface Options<in out A, in out I, in out R, in out SA = void, in out SE = A, out SR = never>
-    extends make.Options<A, I, R, SA, SE, SR> {}
-}
-
-export const service = <A, I = A, R = never, SA = void, SE = A, SR = never>(
-    options: service.Options<A, I, R, SA, SE, SR>
-): Effect.Effect<Form<A, I, R, SA, SE, SR>, never, Scope.Scope | R | SR> => Effect.tap(
-    make(options),
-    form => Effect.forkScoped(run(form)),
-)
-
-export const field = <A, I, R, SA, SE, SR, const P extends PropertyPath.Paths<NoInfer<I>>>(
-    self: Form<A, I, R, SA, SE, SR>,
-    path: P,
-): FormField<PropertyPath.ValueFromPath<A, P>, PropertyPath.ValueFromPath<I, P>> => new FormFieldImpl(
-    Subscribable.mapEffect(self.valueRef, Option.match({
-        onSome: v => Option.map(PropertyPath.get(v, path), Option.some),
-        onNone: () => Option.some(Option.none()),
-    })),
-    SubscriptionSubRef.makeFromPath(self.encodedValueRef, path),
-    Subscribable.mapEffect(self.errorRef, Option.match({
-        onSome: flow(
-            ParseResult.ArrayFormatter.formatError,
-            Effect.map(Array.filter(issue => PropertyPath.equivalence(issue.path, path))),
-        ),
-        onNone: () => Effect.succeed([]),
-    })),
-    Subscribable.map(self.validationFiberRef, Option.isSome),
-    Subscribable.map(self.submitStateRef, AsyncData.isLoading)
-)
-
-
-export const FormFieldTypeId: unique symbol = Symbol.for("effect-fc/FormField")
-export type FormFieldTypeId = typeof FormFieldTypeId
-
-export interface FormField<in out A, in out I = A>
-extends Pipeable.Pipeable {
-    readonly [FormFieldTypeId]: FormFieldTypeId
-
-    readonly valueSubscribable: Subscribable.Subscribable<Option.Option<A>, NoSuchElementException>
-    readonly encodedValueRef: SubscriptionRef.SubscriptionRef<I>
-    readonly issuesSubscribable: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[]>
-    readonly isValidatingSubscribable: Subscribable.Subscribable<boolean>
-    readonly isSubmittingSubscribable: 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 valueSubscribable: Subscribable.Subscribable<Option.Option<A>, NoSuchElementException>,
-        readonly encodedValueRef: SubscriptionRef.SubscriptionRef<I>,
-        readonly issuesSubscribable: Subscribable.Subscribable<readonly ParseResult.ArrayFormatterIssue[]>,
-        readonly isValidatingSubscribable: Subscribable.Subscribable<boolean>,
-        readonly isSubmittingSubscribable: Subscribable.Subscribable<boolean>,
-    ) {
-        super()
-    }
-}
-
-export const isFormField = (u: unknown): u is FormField<unknown, unknown> => Predicate.hasProperty(u, FormFieldTypeId)
-
-
-export const useSubmit = <A, I, R, SA, SE, SR>(
-    self: Form<A, I, R, SA, SE, SR>
-): Effect.Effect<
-    () => Promise<Option.Option<AsyncData.AsyncData<SA, SE>>>,
-    never,
-    SR
-> => Component.useCallbackPromise(() => submit(self), [self])
-
-export const useField = <A, I, R, SA, SE, SR, const P extends PropertyPath.Paths<NoInfer<I>>>(
-    self: Form<A, I, R, SA, SE, SR>,
-    path: P,
-): FormField<
-    PropertyPath.ValueFromPath<A, P>,
-    PropertyPath.ValueFromPath<I, P>
-// biome-ignore lint/correctness/useExhaustiveDependencies: individual path components need to be compared
-> => React.useMemo(() => field(self, path), [self, ...path])
 
 export namespace useInput {
     export interface Options {
         readonly debounce?: Duration.DurationInput
     }
 
-    export interface Result<T> {
+    export interface Success<T> {
         readonly value: T
         readonly setValue: React.Dispatch<React.SetStateAction<T>>
     }
 }
 
-export const useInput: {
+export const useInput = Effect.fnUntraced(function* <P extends readonly PropertyKey[], A, I, ER, EW>(
-    <A, I>(
+    form: Form<P, A, I, ER, EW>,
-        field: FormField<A, I>,
     options?: useInput.Options,
-    ): Effect.Effect<useInput.Result<I>, NoSuchElementException, Scope.Scope>
+): Effect.fn.Return<useInput.Success<I>, ER, Scope.Scope> {
-} = Effect.fnUntraced(function* <A, I>(
+    const internalValueLens = yield* Component.useOnChange(() => Effect.gen(function*() {
-    field: FormField<A, I>,
+        const internalValueLens = yield* Lens.get(form.encodedValue).pipe(
-    options?: useInput.Options,
+            Effect.flatMap(SubscriptionRef.make),
-) {
+            Effect.map(Lens.fromSubscriptionRef),
-    const internalValueRef = yield* Component.useOnChange(() => Effect.tap(
+        )
-        Effect.andThen(field.encodedValueRef, SubscriptionRef.make),
+
-        internalValueRef => Effect.forkScoped(Effect.all([
+        yield* Effect.forkScoped(Effect.all([
             Stream.runForEach(
-                Stream.drop(field.encodedValueRef, 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.encodedValueRef, internalValue),
+                internalValue => Lens.set(form.encodedValue, internalValue),
             ),
-        ], { concurrency: "unbounded" })),
+        ], { concurrency: "unbounded", discard: true }))
-    ), [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 }
 })
 
@@ -302,66 +206,69 @@ export namespace useOptionalInput {
         readonly defaultValue: T
     }
 
-    export interface Result<T> extends useInput.Result<T> {
+    export interface Success<T> extends useInput.Success<T> {
         readonly enabled: boolean
         readonly setEnabled: React.Dispatch<React.SetStateAction<boolean>>
     }
 }
 
-export const useOptionalInput: {
+export const useOptionalInput = Effect.fnUntraced(function* <P extends readonly PropertyKey[], A, I, ER, EW>(
-    <A, I>(
+    field: Form<P, A, Option.Option<I>, ER, EW>,
-        field: FormField<A, Option.Option<I>>,
     options: useOptionalInput.Options<I>,
-    ): Effect.Effect<useOptionalInput.Result<I>, NoSuchElementException, Scope.Scope>
+): Effect.fn.Return<useOptionalInput.Success<I>, ER, Scope.Scope> {
-} = Effect.fnUntraced(function* <A, I>(
+    const [enabledLens, internalValueLens] = yield* Component.useOnChange(() => Effect.gen(function*() {
-    field: FormField<A, Option.Option<I>>,
+        const [enabledLens, internalValueLens] = yield* Effect.flatMap(
-    options: useOptionalInput.Options<I>,
+            Lens.get(field.encodedValue),
-) {
-    const [enabledRef, internalValueRef] = yield* Component.useOnChange(() => Effect.tap(
-        Effect.andThen(
-            field.encodedValueRef,
             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.encodedValueRef, 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.encodedValueRef, 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 +1,62 @@
+import { Effect, Equivalence, Stream, SubscriptionRef } from "effect"
+import { Lens } from "effect-lens"
+import * as React from "react"
+import * as Component from "./Component.js"
+import * as SetStateAction from "./SetStateAction.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 useFromReactState {
+    export interface Options<A> {
+        readonly equivalence?: Equivalence.Equivalence<A>
+    }
+}
+
+export const useFromReactState = Effect.fnUntraced(function* <A>(
+    [value, setValue]: readonly [A, React.Dispatch<React.SetStateAction<A>>],
+    options?: useFromReactState.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/Memoized.ts

@@ -1,50 +1,111 @@
 /** biome-ignore-all lint/complexity/useArrowFunction: necessary for class prototypes */
 import { type Equivalence, Function, Predicate } from "effect"
+import * as React from "react"
 import type * as Component from "./Component.js"
 
 
-export const TypeId: unique symbol = Symbol.for("@effect-fc/Memoized/Memoized")
+export const MemoizedTypeId: unique symbol = Symbol.for("@effect-fc/Memoized/Memoized")
-export type TypeId = typeof TypeId
+export type MemoizedTypeId = typeof MemoizedTypeId
 
-export interface Memoized<P> extends Memoized.Options<P> {
+
-    readonly [TypeId]: TypeId
+/**
+ * A trait for `Component`'s that uses `React.memo` to optimize re-renders based on prop equality.
+ *
+ * @template P The props type of the component
+ */
+export interface Memoized<P> extends MemoizedPrototype, MemoizedOptions<P> {}
+
+export interface MemoizedPrototype {
+    readonly [MemoizedTypeId]: MemoizedTypeId
 }
 
-export namespace Memoized {
+/**
-    export interface Options<P> {
+ * Configuration options for Memoized components.
-        readonly propsAreEqual?: Equivalence.Equivalence<P>
+ *
-    }
+ * @template P The props type of the component
+ */
+export interface MemoizedOptions<P> {
+    /**
+     * An optional equivalence function for comparing component props.
+     * If provided, this function is used by React.memo to determine if props have changed.
+     * Returns `true` if props are equivalent (no re-render), `false` if they differ (re-render).
+     */
+    readonly propsEquivalence?: Equivalence.Equivalence<P>
 }
 
 
-const MemoizedProto = Object.freeze({
+export const MemoizedPrototype: MemoizedPrototype = Object.freeze({
-    [TypeId]: TypeId
+    [MemoizedTypeId]: MemoizedTypeId,
+
+    transformFunctionComponent<P extends {}>(
+        this: Memoized<P>,
+        f: React.FC<P>,
+    ) {
+        return React.memo(f, this.propsEquivalence)
+    },
 } as const)
 
 
-export const isMemoized = (u: unknown): u is Memoized<unknown> => Predicate.hasProperty(u, TypeId)
+export const isMemoized = (u: unknown): u is Memoized<unknown> => Predicate.hasProperty(u, MemoizedTypeId)
 
-export const memoized = <T extends Component.Component<any, any, any, any>>(
+/**
+ * Converts a Component into a `Memoized` component that optimizes re-renders using `React.memo`.
+ *
+ * @param self - The component to convert to a Memoized component
+ * @returns A new `Memoized` component with the same body, error, and context types as the input
+ *
+ * @example
+ * ```ts
+ * const MyMemoizedComponent = MyComponent.pipe(
+ *   Memoized.memoized,
+ * )
+ * ```
+ */
+export const memoized = <T extends Component.Component.Any>(
     self: T
 ): T & Memoized<Component.Component.Props<T>> => Object.setPrototypeOf(
     Object.assign(function() {}, self),
     Object.freeze(Object.setPrototypeOf(
-        Object.assign({}, MemoizedProto),
+        Object.assign({}, MemoizedPrototype),
         Object.getPrototypeOf(self),
     )),
 )
 
+/**
+ * Applies options to a Memoized component, returning a new Memoized component with the updated configuration.
+ *
+ * Supports both curried and uncurried application styles.
+ *
+ * @param self - The Memoized component to apply options to (in uncurried form)
+ * @param options - The options to apply to the component
+ * @returns A Memoized component with the applied options
+ *
+ * @example
+ * ```ts
+ * // Curried
+ * const MyMemoizedComponent = MyComponent.pipe(
+ *   Memoized.memoized,
+ *   Memoized.withOptions({ propsEquivalence: (a, b) => a.id === b.id }),
+ * )
+ *
+ * // Uncurried
+ * const MyMemoizedComponent = Memoized.withOptions(
+ *   Memoized.memoized(MyComponent),
+ *   { propsEquivalence: (a, b) => a.id === b.id },
+ * )
+ * ```
+ */
 export const withOptions: {
-    <T extends Component.Component<any, any, any, any> & Memoized<any>>(
+    <T extends Component.Component.Any & Memoized<any>>(
-        options: Partial<Memoized.Options<Component.Component.Props<T>>>
+        options: Partial<MemoizedOptions<Component.Component.Props<T>>>
     ): (self: T) => T
-    <T extends Component.Component<any, any, any, any> & Memoized<any>>(
+    <T extends Component.Component.Any & Memoized<any>>(
         self: T,
-        options: Partial<Memoized.Options<Component.Component.Props<T>>>,
+        options: Partial<MemoizedOptions<Component.Component.Props<T>>>,
     ): T
-} = Function.dual(2, <T extends Component.Component<any, any, any, any> & Memoized<any>>(
+} = Function.dual(2, <T extends Component.Component.Any & Memoized<any>>(
     self: T,
-    options: Partial<Memoized.Options<Component.Component.Props<T>>>,
+    options: Partial<MemoizedOptions<Component.Component.Props<T>>>,
 ): T => Object.setPrototypeOf(
     Object.assign(function() {}, self, options),
     Object.getPrototypeOf(self),

packages/effect-fc/src/Mutation.ts

@@ -0,0 +1,130 @@
+import { type Context, Effect, Equal, type Fiber, Option, Pipeable, Predicate, type Scope, Stream, type Subscribable, SubscriptionRef } from "effect"
+import * as Result from "./Result.js"
+
+
+export const MutationTypeId: unique symbol = Symbol.for("@effect-fc/Mutation/Mutation")
+export type MutationTypeId = typeof MutationTypeId
+
+export interface Mutation<in out K extends Mutation.AnyKey, in out A, in out E = never, in out R = never, in out P = never>
+extends Pipeable.Pipeable {
+    readonly [MutationTypeId]: MutationTypeId
+
+    readonly context: Context.Context<Scope.Scope | R>
+    readonly f: (key: K) => Effect.Effect<A, E, R>
+    readonly initialProgress: P
+
+    readonly latestKey: Subscribable.Subscribable<Option.Option<K>>
+    readonly fiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, E>>>
+    readonly result: Subscribable.Subscribable<Result.Result<A, E, P>>
+    readonly latestFinalResult: Subscribable.Subscribable<Option.Option<Result.Final<A, E, P>>>
+
+    mutate(key: K): Effect.Effect<Result.Final<A, E, P>>
+    mutateSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>>
+}
+
+export declare namespace Mutation {
+    export type AnyKey = readonly any[]
+}
+
+export class MutationImpl<in out K extends Mutation.AnyKey, in out A, in out E = never, in out R = never, in out P = never>
+extends Pipeable.Class() implements Mutation<K, A, E, R, P> {
+    readonly [MutationTypeId]: MutationTypeId = MutationTypeId
+
+    constructor(
+        readonly context: Context.Context<Scope.Scope | R>,
+        readonly f: (key: K) => Effect.Effect<A, E, R>,
+        readonly initialProgress: P,
+
+        readonly latestKey: SubscriptionRef.SubscriptionRef<Option.Option<K>>,
+        readonly fiber: SubscriptionRef.SubscriptionRef<Option.Option<Fiber.Fiber<A, E>>>,
+        readonly result: SubscriptionRef.SubscriptionRef<Result.Result<A, E, P>>,
+        readonly latestFinalResult: SubscriptionRef.SubscriptionRef<Option.Option<Result.Final<A, E, P>>>,
+    ) {
+        super()
+    }
+
+    mutate(key: K): Effect.Effect<Result.Final<A, E, P>> {
+        return SubscriptionRef.set(this.latestKey, Option.some(key)).pipe(
+            Effect.andThen(this.start(key)),
+            Effect.andThen(sub => this.watch(sub)),
+            Effect.provide(this.context),
+        )
+    }
+    mutateSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>> {
+        return SubscriptionRef.set(this.latestKey, Option.some(key)).pipe(
+            Effect.andThen(this.start(key)),
+            Effect.tap(sub => Effect.forkScoped(this.watch(sub))),
+            Effect.provide(this.context),
+        )
+    }
+
+    start(key: K): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        never,
+        Scope.Scope | R
+    > {
+        return this.latestFinalResult.pipe(
+            Effect.andThen(initial => Result.unsafeForkEffect(
+                Effect.onExit(this.f(key), () => Effect.andThen(
+                    Effect.all([Effect.fiberId, this.fiber]),
+                    ([currentFiberId, fiber]) => Option.match(fiber, {
+                        onSome: v => Equal.equals(currentFiberId, v.id())
+                            ? SubscriptionRef.set(this.fiber, Option.none())
+                            : Effect.void,
+                        onNone: () => Effect.void,
+                    }),
+                )),
+
+                {
+                    initial: Option.isSome(initial) ? Result.willFetch(initial.value) : Result.initial(),
+                    initialProgress: this.initialProgress,
+                } as Result.unsafeForkEffect.Options<A, E, P>,
+            )),
+            Effect.tap(([, fiber]) => SubscriptionRef.set(this.fiber, Option.some(fiber))),
+            Effect.map(([sub]) => sub),
+        )
+    }
+
+    watch(
+        sub: Subscribable.Subscribable<Result.Result<A, E, P>>
+    ): Effect.Effect<Result.Final<A, E, P>> {
+        return sub.get.pipe(
+            Effect.andThen(initial => Stream.runFoldEffect(
+                sub.changes,
+                initial,
+                (_, result) => Effect.as(SubscriptionRef.set(this.result, result), result),
+            ) as Effect.Effect<Result.Final<A, E, P>>),
+            Effect.tap(result => SubscriptionRef.set(this.latestFinalResult, Option.some(result))),
+        )
+    }
+}
+
+
+export const isMutation = (u: unknown): u is Mutation<readonly unknown[], unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, MutationTypeId)
+
+
+export declare namespace make {
+    export interface Options<K extends Mutation.AnyKey = never, A = void, E = never, R = never, P = never> {
+        readonly f: (key: K) => Effect.Effect<A, E, Result.forkEffect.InputContext<R, NoInfer<P>>>
+        readonly initialProgress?: P
+    }
+}
+
+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<R, P>, P>,
+    never,
+    Scope.Scope | Result.forkEffect.OutputContext<R, P>
+> {
+    return new MutationImpl(
+        yield* Effect.context<Scope.Scope | Result.forkEffect.OutputContext<R, P>>(),
+        options.f as any,
+        options.initialProgress as P,
+
+        yield* SubscriptionRef.make(Option.none<K>()),
+        yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, E>>()),
+        yield* SubscriptionRef.make(Result.initial<A, E, P>()),
+        yield* SubscriptionRef.make(Option.none<Result.Final<A, E, P>>()),
+    )
+})

packages/effect-fc/src/PropertyPath.ts

@@ -1,98 +0,0 @@
-import { Array, Equivalence, Function, Option, Predicate } from "effect"
-
-
-export type PropertyPath = readonly PropertyKey[]
-
-type Prev = readonly [never, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
-
-export type Paths<T, D extends number = 5, Seen = never> = readonly [] | (
-    D extends never ? readonly [] :
-    T extends Seen ? readonly [] :
-    T extends readonly any[] ? {
-        [K in keyof T as K extends number ? K : never]:
-            | readonly [K]
-            | readonly [K, ...Paths<T[K], Prev[D], Seen | T>]
-    } extends infer O
-        ? O[keyof O]
-        : never
-    :
-    T extends object ? {
-        [K in keyof T as K extends string | number | symbol ? K : never]-?:
-            NonNullable<T[K]> extends infer V
-                ? readonly [K] | readonly [K, ...Paths<V, Prev[D], Seen>]
-                : never
-    } extends infer O
-        ? O[keyof O]
-        : never
-    :
-    never
-)
-
-export type ValueFromPath<T, P extends readonly any[]> = P extends readonly [infer Head, ...infer Tail]
-    ? Head extends keyof T
-        ? ValueFromPath<T[Head], Tail>
-        : T extends readonly any[]
-            ? Head extends number
-                ? ValueFromPath<T[number], Tail>
-                : never
-            : never
-    : T
-
-
-export const equivalence: Equivalence.Equivalence<PropertyPath> = Equivalence.array(Equivalence.strict())
-
-export const unsafeGet: {
-    <T, const P extends Paths<T>>(path: P): (self: T) => ValueFromPath<T, P>
-    <T, const P extends Paths<T>>(self: T, path: P): ValueFromPath<T, P>
-} = Function.dual(2, <T, const P extends Paths<T>>(self: T, path: P): ValueFromPath<T, P> =>
-    path.reduce((acc: any, key: any) => acc?.[key], self)
-)
-
-export const get: {
-    <T, const P extends Paths<T>>(path: P): (self: T) => Option.Option<ValueFromPath<T, P>>
-    <T, const P extends Paths<T>>(self: T, path: P): Option.Option<ValueFromPath<T, P>>
-} = Function.dual(2, <T, const P extends Paths<T>>(self: T, path: P): Option.Option<ValueFromPath<T, P>> =>
-    path.reduce(
-        (acc: Option.Option<any>, key: any): Option.Option<any> => Option.isSome(acc)
-            ? Predicate.hasProperty(acc.value, key)
-                ? Option.some(acc.value[key])
-                : Option.none()
-            : acc,
-
-        Option.some(self),
-    )
-)
-
-export const immutableSet: {
-    <T, const P extends Paths<T>>(path: P, value: ValueFromPath<T, P>): (self: T) => Option.Option<T>
-    <T, const P extends Paths<T>>(self: T, path: P, value: ValueFromPath<T, P>): Option.Option<T>
-} = Function.dual(3, <T, const P extends Paths<T>>(self: T, path: P, value: ValueFromPath<T, P>): Option.Option<T> => {
-    const key = Array.head(path as PropertyPath)
-    if (Option.isNone(key))
-        return Option.some(value as T)
-    if (!Predicate.hasProperty(self, key.value))
-        return Option.none()
-
-    const child = immutableSet<any, any>(self[key.value], Option.getOrThrow(Array.tail(path as PropertyPath)), value)
-    if (Option.isNone(child))
-        return child
-
-    if (Array.isArray(self))
-        return typeof key.value === "number"
-            ? Option.some([
-                ...self.slice(0, key.value),
-                child.value,
-                ...self.slice(key.value + 1),
-            ] as T)
-            : Option.none()
-
-    if (typeof self === "object")
-        return Option.some(
-            Object.assign(
-                Object.create(Object.getPrototypeOf(self)),
-                { ...self, [key.value]: child.value },
-            )
-        )
-
-    return Option.none()
-})

packages/effect-fc/src/PubSub.ts

@@ -0,0 +1,14 @@
+import { Effect, PubSub, type Scope } from "effect"
+import type * as React from "react"
+import * as Component from "./Component.js"
+
+
+export const useFromReactiveValues = Effect.fnUntraced(function* <const A extends React.DependencyList>(
+    values: A
+): Effect.fn.Return<PubSub.PubSub<A>, never, Scope.Scope> {
+    const pubsub = yield* Component.useOnMount(() => Effect.acquireRelease(PubSub.unbounded<A>(), PubSub.shutdown))
+    yield* Component.useReactEffect(() => Effect.unlessEffect(PubSub.publish(pubsub, values), PubSub.isShutdown(pubsub)), values)
+    return pubsub
+})
+
+export * from "effect/PubSub"

packages/effect-fc/src/Query.ts

@@ -0,0 +1,319 @@
+import { type Cause, type Context, type Duration, Effect, Equal, Fiber, identity, Option, Pipeable, Predicate, type Scope, Stream, Subscribable, SubscriptionRef } from "effect"
+import * as QueryClient from "./QueryClient.js"
+import * as Result from "./Result.js"
+
+
+export const QueryTypeId: unique symbol = Symbol.for("@effect-fc/Query/Query")
+export type QueryTypeId = typeof QueryTypeId
+
+export interface Query<in out K extends Query.AnyKey, in out A, in out KE = never, in out KR = never, in out E = never, in out R = never, in out P = never>
+extends Pipeable.Pipeable {
+    readonly [QueryTypeId]: QueryTypeId
+
+    readonly context: Context.Context<Scope.Scope | QueryClient.QueryClient | KR | R>
+    readonly key: Stream.Stream<K, KE, KR>
+    readonly f: (key: K) => Effect.Effect<A, E, R>
+    readonly initialProgress: P
+
+    readonly staleTime: Duration.DurationInput
+    readonly refreshOnWindowFocus: boolean
+
+    readonly latestKey: Subscribable.Subscribable<Option.Option<K>>
+    readonly fiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, E>>>
+    readonly result: Subscribable.Subscribable<Result.Result<A, E, P>>
+    readonly latestFinalResult: Subscribable.Subscribable<Option.Option<Result.Final<A, E, P>>>
+
+    readonly run: Effect.Effect<void>
+    fetch(key: K): Effect.Effect<Result.Final<A, E, P>>
+    fetchSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>>
+    readonly refresh: Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException>
+    readonly refreshSubscribable: Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>, Cause.NoSuchElementException>
+
+    readonly invalidateCache: Effect.Effect<void>
+    invalidateCacheEntry(key: K): Effect.Effect<void>
+}
+
+export declare namespace Query {
+    export type AnyKey = readonly any[]
+}
+
+export class QueryImpl<in out K extends Query.AnyKey, in out A, in out KE = never, in out KR = never, in out E = never, in out R = never, in out P = never>
+extends Pipeable.Class() implements Query<K, A, KE, KR, E, R, P> {
+    readonly [QueryTypeId]: QueryTypeId = QueryTypeId
+
+    constructor(
+        readonly context: Context.Context<Scope.Scope | QueryClient.QueryClient | KR | R>,
+        readonly key: Stream.Stream<K, KE, KR>,
+        readonly f: (key: K) => Effect.Effect<A, E, R>,
+        readonly initialProgress: P,
+
+        readonly staleTime: Duration.DurationInput,
+        readonly refreshOnWindowFocus: boolean,
+
+        readonly latestKey: SubscriptionRef.SubscriptionRef<Option.Option<K>>,
+        readonly fiber: SubscriptionRef.SubscriptionRef<Option.Option<Fiber.Fiber<A, E>>>,
+        readonly result: SubscriptionRef.SubscriptionRef<Result.Result<A, E, P>>,
+        readonly latestFinalResult: SubscriptionRef.SubscriptionRef<Option.Option<Result.Final<A, E, P>>>,
+
+        readonly runSemaphore: Effect.Semaphore,
+    ) {
+        super()
+    }
+
+    get run(): Effect.Effect<void> {
+        return Effect.all([
+            Stream.runForEach(this.key, key => this.fetchSubscribable(key)),
+
+            Effect.promise(() => import("@effect/platform-browser")).pipe(
+                Effect.andThen(({ BrowserStream }) => this.refreshOnWindowFocus
+                    ? Stream.runForEach(
+                        BrowserStream.fromEventListenerWindow("focus"),
+                        () => this.refreshSubscribable,
+                    )
+                    : Effect.void
+                ),
+                Effect.catchAllDefect(() => Effect.void),
+            ),
+        ], { concurrency: "unbounded" }).pipe(
+            Effect.ignore,
+            this.runSemaphore.withPermits(1),
+            Effect.provide(this.context),
+        )
+    }
+
+    get interrupt(): Effect.Effect<void> {
+        return Effect.andThen(this.fiber, Option.match({
+            onSome: Fiber.interrupt,
+            onNone: () => Effect.void,
+        }))
+    }
+
+    fetch(key: K): Effect.Effect<Result.Final<A, E, P>> {
+        return this.interrupt.pipe(
+            Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
+            Effect.andThen(this.latestFinalResult),
+            Effect.andThen(previous => this.startCached(key, Option.isSome(previous)
+                ? Result.willFetch(previous.value) as Result.Final<A, E, P>
+                : Result.initial()
+            )),
+            Effect.andThen(sub => this.watch(key, sub)),
+            Effect.provide(this.context),
+        )
+    }
+
+    fetchSubscribable(key: K): Effect.Effect<Subscribable.Subscribable<Result.Result<A, E, P>>> {
+        return this.interrupt.pipe(
+            Effect.andThen(SubscriptionRef.set(this.latestKey, Option.some(key))),
+            Effect.andThen(this.latestFinalResult),
+            Effect.andThen(previous => this.startCached(key, Option.isSome(previous)
+                ? Result.willFetch(previous.value) as Result.Final<A, E, P>
+                : Result.initial()
+            )),
+            Effect.tap(sub => Effect.forkScoped(this.watch(key, sub))),
+            Effect.provide(this.context),
+        )
+    }
+
+    get refresh(): Effect.Effect<Result.Final<A, E, P>, Cause.NoSuchElementException> {
+        return this.interrupt.pipe(
+            Effect.andThen(Effect.Do),
+            Effect.bind("latestKey", () => Effect.andThen(this.latestKey, identity)),
+            Effect.bind("latestFinalResult", () => this.latestFinalResult),
+            Effect.bind("subscribable", ({ latestKey, latestFinalResult }) =>
+                this.startCached(latestKey, Option.isSome(latestFinalResult)
+                    ? Result.willRefresh(latestFinalResult.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                )
+            ),
+            Effect.andThen(({ latestKey, subscribable }) => this.watch(latestKey, subscribable)),
+            Effect.provide(this.context),
+        )
+    }
+
+    get refreshSubscribable(): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        Cause.NoSuchElementException
+    > {
+        return this.interrupt.pipe(
+            Effect.andThen(Effect.Do),
+            Effect.bind("latestKey", () => Effect.andThen(this.latestKey, identity)),
+            Effect.bind("latestFinalResult", () => this.latestFinalResult),
+            Effect.bind("subscribable", ({ latestKey, latestFinalResult }) =>
+                this.startCached(latestKey, Option.isSome(latestFinalResult)
+                    ? Result.willRefresh(latestFinalResult.value) as Result.Final<A, E, P>
+                    : Result.initial()
+                )
+            ),
+            Effect.tap(({ latestKey, subscribable }) => Effect.forkScoped(this.watch(latestKey, subscribable))),
+            Effect.map(({ subscribable }) => subscribable),
+            Effect.provide(this.context),
+        )
+    }
+
+    startCached(
+        key: K,
+        initial: Result.Initial | Result.Final<A, E, P>,
+    ): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        never,
+        Scope.Scope | QueryClient.QueryClient | R
+    > {
+        return Effect.andThen(this.getCacheEntry(key), Option.match({
+            onSome: entry => Effect.andThen(
+                QueryClient.isQueryClientCacheEntryStale(entry),
+                isStale => isStale
+                    ? this.start(key, Result.willRefresh(entry.result) as Result.Final<A, E, P>)
+                    : Effect.succeed(Subscribable.make({
+                        get: Effect.succeed(entry.result as Result.Result<A, E, P>),
+                        get changes() { return Stream.make(entry.result as Result.Result<A, E, P>) },
+                    })),
+            ),
+            onNone: () => this.start(key, initial),
+        }))
+    }
+
+    start(
+        key: K,
+        initial: Result.Initial | Result.Final<A, E, P>,
+    ): Effect.Effect<
+        Subscribable.Subscribable<Result.Result<A, E, P>>,
+        never,
+        Scope.Scope | R
+    > {
+        return Result.unsafeForkEffect(
+            Effect.onExit(this.f(key), () => Effect.andThen(
+                Effect.all([Effect.fiberId, this.fiber]),
+                ([currentFiberId, fiber]) => Option.match(fiber, {
+                    onSome: v => Equal.equals(currentFiberId, v.id())
+                        ? SubscriptionRef.set(this.fiber, Option.none())
+                        : Effect.void,
+                    onNone: () => Effect.void,
+                }),
+            )),
+
+            {
+                initial,
+                initialProgress: this.initialProgress,
+            } as Result.unsafeForkEffect.Options<A, E, P>,
+        ).pipe(
+            Effect.tap(([, fiber]) => SubscriptionRef.set(this.fiber, Option.some(fiber))),
+            Effect.map(([sub]) => sub),
+        )
+    }
+
+    watch(
+        key: K,
+        sub: Subscribable.Subscribable<Result.Result<A, E, P>>
+    ): Effect.Effect<Result.Final<A, E, P>, never, QueryClient.QueryClient> {
+        return sub.get.pipe(
+            Effect.andThen(initial => Stream.runFoldEffect(
+                sub.changes,
+                initial,
+                (_, result) => Effect.as(SubscriptionRef.set(this.result, result), result),
+            ) as Effect.Effect<Result.Final<A, E, P>>),
+            Effect.tap(result => SubscriptionRef.set(this.latestFinalResult, Option.some(result))),
+            Effect.tap(result => Result.isSuccess(result)
+                ? this.setCacheEntry(key, result)
+                : Effect.void
+            ),
+        )
+    }
+
+    makeCacheKey(key: K): QueryClient.QueryClientCacheKey {
+        return new QueryClient.QueryClientCacheKey(key, this.f as (key: Query.AnyKey) => Effect.Effect<unknown, unknown, unknown>)
+    }
+
+    getCacheEntry(
+        key: K
+    ): Effect.Effect<Option.Option<QueryClient.QueryClientCacheEntry>, never, QueryClient.QueryClient> {
+        return Effect.andThen(
+            Effect.all([
+                Effect.succeed(this.makeCacheKey(key)),
+                QueryClient.QueryClient,
+            ]),
+            ([key, client]) => client.getCacheEntry(key),
+        )
+    }
+
+    setCacheEntry(
+        key: K,
+        result: Result.Success<A>,
+    ): Effect.Effect<QueryClient.QueryClientCacheEntry, never, QueryClient.QueryClient> {
+        return Effect.andThen(
+            Effect.all([
+                Effect.succeed(this.makeCacheKey(key)),
+                QueryClient.QueryClient,
+            ]),
+            ([key, client]) => client.setCacheEntry(key, result, this.staleTime),
+        )
+    }
+
+    get invalidateCache(): Effect.Effect<void> {
+        return QueryClient.QueryClient.pipe(
+            Effect.andThen(client => client.invalidateCacheEntries(this.f as (key: Query.AnyKey) => Effect.Effect<unknown, unknown, unknown>)),
+            Effect.provide(this.context),
+        )
+    }
+
+    invalidateCacheEntry(key: K): Effect.Effect<void> {
+        return Effect.all([
+            Effect.succeed(this.makeCacheKey(key)),
+            QueryClient.QueryClient,
+        ]).pipe(
+            Effect.andThen(([key, client]) => client.invalidateCacheEntry(key)),
+            Effect.provide(this.context),
+        )
+    }
+}
+
+
+export const isQuery = (u: unknown): u is Query<readonly unknown[], unknown> => Predicate.hasProperty(u, QueryTypeId)
+
+
+export declare namespace make {
+    export interface Options<K extends Query.AnyKey, A, KE = never, KR = never, E = never, R = never, P = never> {
+        readonly key: Stream.Stream<K, KE, KR>
+        readonly f: (key: NoInfer<K>) => Effect.Effect<A, E, Result.forkEffect.InputContext<R, NoInfer<P>>>
+        readonly initialProgress?: P
+        readonly staleTime?: Duration.DurationInput
+        readonly refreshOnWindowFocus?: boolean
+    }
+}
+
+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<R, P>, P>,
+    never,
+    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<R, P>, P>(
+        yield* Effect.context<Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<R, P>>(),
+        options.key,
+        options.f as any,
+        options.initialProgress as P,
+
+        options.staleTime ?? client.defaultStaleTime,
+        options.refreshOnWindowFocus ?? client.defaultRefreshOnWindowFocus,
+
+        yield* SubscriptionRef.make(Option.none<K>()),
+        yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, E>>()),
+        yield* SubscriptionRef.make(Result.initial<A, E, P>()),
+        yield* SubscriptionRef.make(Option.none<Result.Final<A, E, P>>()),
+
+        yield* Effect.makeSemaphore(1),
+    )
+})
+
+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<R, P>, P>,
+    never,
+    Scope.Scope | QueryClient.QueryClient | KR | Result.forkEffect.OutputContext<R, P>
+> => Effect.tap(
+    make(options),
+    query => Effect.forkScoped(query.run),
+)

packages/effect-fc/src/QueryClient.ts

@@ -0,0 +1,173 @@
+import { DateTime, Duration, Effect, Equal, Equivalence, Hash, HashMap, type Option, Pipeable, Predicate, Schedule, type Scope, type Subscribable, SubscriptionRef } from "effect"
+import type * as Query from "./Query.js"
+import type * as Result from "./Result.js"
+
+
+export const QueryClientServiceTypeId: unique symbol = Symbol.for("@effect-fc/QueryClient/QueryClientService")
+export type QueryClientServiceTypeId = typeof QueryClientServiceTypeId
+
+export interface QueryClientService extends Pipeable.Pipeable {
+    readonly [QueryClientServiceTypeId]: QueryClientServiceTypeId
+
+    readonly cache: Subscribable.Subscribable<HashMap.HashMap<QueryClientCacheKey, QueryClientCacheEntry>>
+    readonly cacheGcTime: Duration.DurationInput
+    readonly defaultStaleTime: Duration.DurationInput
+    readonly defaultRefreshOnWindowFocus: boolean
+
+    readonly run: Effect.Effect<void>
+    getCacheEntry(key: QueryClientCacheKey): Effect.Effect<Option.Option<QueryClientCacheEntry>>
+    setCacheEntry(
+        key: QueryClientCacheKey,
+        result: Result.Success<unknown>,
+        staleTime: Duration.DurationInput,
+    ): Effect.Effect<QueryClientCacheEntry>
+    invalidateCacheEntries(f: (key: Query.Query.AnyKey) => Effect.Effect<unknown, unknown, unknown>): Effect.Effect<void>
+    invalidateCacheEntry(key: QueryClientCacheKey): Effect.Effect<void>
+}
+
+export class QueryClient extends Effect.Service<QueryClient>()("@effect-fc/QueryClient/QueryClient", {
+    scoped: Effect.suspend(() => service())
+}) {}
+
+export class QueryClientServiceImpl
+extends Pipeable.Class()
+implements QueryClientService {
+    readonly [QueryClientServiceTypeId]: QueryClientServiceTypeId = QueryClientServiceTypeId
+
+    constructor(
+        readonly cache: SubscriptionRef.SubscriptionRef<HashMap.HashMap<QueryClientCacheKey, QueryClientCacheEntry>>,
+        readonly cacheGcTime: Duration.DurationInput,
+        readonly defaultStaleTime: Duration.DurationInput,
+        readonly defaultRefreshOnWindowFocus: boolean,
+        readonly runSemaphore: Effect.Semaphore,
+    ) {
+        super()
+    }
+
+    get run(): Effect.Effect<void> {
+        return this.runSemaphore.withPermits(1)(Effect.repeat(
+            Effect.andThen(
+                DateTime.now,
+                now => SubscriptionRef.update(this.cache, HashMap.filter(entry =>
+                    Duration.lessThan(
+                        DateTime.distanceDuration(entry.lastAccessedAt, now),
+                        Duration.sum(entry.staleTime, this.cacheGcTime),
+                    )
+                )),
+            ),
+            Schedule.spaced("30 second"),
+        ))
+    }
+
+    getCacheEntry(key: QueryClientCacheKey): Effect.Effect<Option.Option<QueryClientCacheEntry>> {
+        return Effect.all([
+            Effect.andThen(this.cache, HashMap.get(key)),
+            DateTime.now,
+        ]).pipe(
+            Effect.map(([entry, now]) => new QueryClientCacheEntry(entry.result, entry.staleTime, entry.createdAt, now)),
+            Effect.tap(entry => SubscriptionRef.update(this.cache, HashMap.set(key, entry))),
+            Effect.option,
+        )
+    }
+
+    setCacheEntry(
+        key: QueryClientCacheKey,
+        result: Result.Success<unknown>,
+        staleTime: Duration.DurationInput,
+    ): Effect.Effect<QueryClientCacheEntry> {
+        return DateTime.now.pipe(
+            Effect.map(now => new QueryClientCacheEntry(result, staleTime, now, now)),
+            Effect.tap(entry => SubscriptionRef.update(this.cache, HashMap.set(key, entry))),
+        )
+    }
+
+    invalidateCacheEntries(f: (key: Query.Query.AnyKey) => Effect.Effect<unknown, unknown, unknown>): Effect.Effect<void> {
+        return SubscriptionRef.update(this.cache, HashMap.filter((_, key) => !Equivalence.strict()(key.f, f)))
+    }
+    invalidateCacheEntry(key: QueryClientCacheKey): Effect.Effect<void> {
+        return SubscriptionRef.update(this.cache, HashMap.remove(key))
+    }
+}
+
+export const isQueryClientService = (u: unknown): u is QueryClientService => Predicate.hasProperty(u, QueryClientServiceTypeId)
+
+export declare namespace make {
+    export interface Options {
+        readonly cacheGcTime?: Duration.DurationInput
+        readonly defaultStaleTime?: Duration.DurationInput
+        readonly defaultRefreshOnWindowFocus?: boolean
+    }
+}
+
+export const make = Effect.fnUntraced(function* (options: make.Options = {}): Effect.fn.Return<QueryClientService> {
+    return new QueryClientServiceImpl(
+        yield* SubscriptionRef.make(HashMap.empty<QueryClientCacheKey, QueryClientCacheEntry>()),
+        options.cacheGcTime ?? "5 minutes",
+        options.defaultStaleTime ?? "0 minutes",
+        options.defaultRefreshOnWindowFocus ?? true,
+        yield* Effect.makeSemaphore(1),
+    )
+})
+
+export declare namespace service {
+    export interface Options extends make.Options {}
+}
+
+export const service = (options?: service.Options): Effect.Effect<QueryClientService, never, Scope.Scope> => Effect.tap(
+    make(options),
+    client => Effect.forkScoped(client.run),
+)
+
+
+export const QueryClientCacheKeyTypeId: unique symbol = Symbol.for("@effect-fc/QueryClient/QueryClientCacheKey")
+export type QueryClientCacheKeyTypeId = typeof QueryClientCacheKeyTypeId
+
+export class QueryClientCacheKey
+extends Pipeable.Class()
+implements Pipeable.Pipeable, Equal.Equal {
+    readonly [QueryClientCacheKeyTypeId]: QueryClientCacheKeyTypeId = QueryClientCacheKeyTypeId
+
+    constructor(
+        readonly key: Query.Query.AnyKey,
+        readonly f: (key: Query.Query.AnyKey) => Effect.Effect<unknown, unknown, unknown>,
+    ) {
+        super()
+    }
+
+    [Equal.symbol](that: Equal.Equal) {
+        return isQueryClientCacheKey(that) && Equivalence.array(Equal.equivalence())(this.key, that.key) && Equivalence.strict()(this.f, that.f)
+    }
+    [Hash.symbol]() {
+        return Hash.combine(Hash.hash(this.f))(Hash.array(this.key))
+    }
+}
+
+export const isQueryClientCacheKey = (u: unknown): u is QueryClientCacheKey => Predicate.hasProperty(u, QueryClientCacheKeyTypeId)
+
+
+export const QueryClientCacheEntryTypeId: unique symbol = Symbol.for("@effect-fc/QueryClient/QueryClientCacheEntry")
+export type QueryClientCacheEntryTypeId = typeof QueryClientCacheEntryTypeId
+
+export class QueryClientCacheEntry
+extends Pipeable.Class()
+implements Pipeable.Pipeable {
+    readonly [QueryClientCacheEntryTypeId]: QueryClientCacheEntryTypeId = QueryClientCacheEntryTypeId
+
+    constructor(
+        readonly result: Result.Success<unknown>,
+        readonly staleTime: Duration.DurationInput,
+        readonly createdAt: DateTime.DateTime,
+        readonly lastAccessedAt: DateTime.DateTime,
+    ) {
+        super()
+    }
+}
+
+export const isQueryClientCacheEntry = (u: unknown): u is QueryClientCacheEntry => Predicate.hasProperty(u, QueryClientCacheEntryTypeId)
+
+export const isQueryClientCacheEntryStale = (
+    self: QueryClientCacheEntry
+): Effect.Effect<boolean> => Effect.andThen(
+    DateTime.now,
+    now => Duration.greaterThanOrEqualTo(DateTime.distanceDuration(self.createdAt, now), self.staleTime),
+)

packages/effect-fc/src/ReactRuntime.ts

@@ -1,7 +1,9 @@
 /** biome-ignore-all lint/complexity/useArrowFunction: necessary for class prototypes */
-import { Effect, Layer, ManagedRuntime, Predicate, type Runtime } from "effect"
+import { Effect, Layer, ManagedRuntime, Predicate, Runtime, Scope } from "effect"
 import * as React from "react"
 import * as Component from "./Component.js"
+import * as ErrorObserver from "./ErrorObserver.js"
+import * as QueryClient from "./QueryClient.js"
 
 
 export const TypeId: unique symbol = Symbol.for("@effect-fc/ReactRuntime/ReactRuntime")
@@ -16,16 +18,26 @@ export interface ReactRuntime<R, ER> {
 
 const ReactRuntimeProto = Object.freeze({ [TypeId]: TypeId } as const)
 
+export const Prelude: Layer.Layer<
+    | Component.ScopeMap
+    | ErrorObserver.ErrorObserver
+    | QueryClient.QueryClient
+> = Layer.mergeAll(
+    Component.ScopeMap.Default,
+    ErrorObserver.layer,
+    QueryClient.QueryClient.Default,
+)
+
 
 export const isReactRuntime = (u: unknown): u is ReactRuntime<unknown, unknown> => Predicate.hasProperty(u, TypeId)
 
 export const make = <R, ER>(
     layer: Layer.Layer<R, ER>,
     memoMap?: Layer.MemoMap,
-): ReactRuntime<R | Component.ScopeMap, ER> => Object.setPrototypeOf(
+): ReactRuntime<Layer.Layer.Success<typeof Prelude> | R, ER> => Object.setPrototypeOf(
     Object.assign(function() {}, {
         runtime: ManagedRuntime.make(
-            Layer.merge(layer, Component.ScopeMap.Default),
+            Layer.merge(layer, Prelude),
             memoMap,
         ),
         // biome-ignore lint/style/noNonNullAssertion: context initialization
@@ -54,16 +66,20 @@ export const Provider = <R, ER>(
     )
 }
 
-interface ProviderInnerProps<R, ER> {
+const ProviderInner = <R, ER>(
+    { runtime, promise, children }: {
         readonly runtime: ReactRuntime<R, ER>
         readonly promise: Promise<Runtime.Runtime<R>>
         readonly children?: React.ReactNode
     }
+): React.ReactNode => {
+    const effectRuntime = React.use(promise)
+    const scope = Runtime.runSync(effectRuntime)(Component.useScope([effectRuntime]))
+    Runtime.runSync(effectRuntime)(Effect.provideService(
+        Component.useOnChange(() => Effect.addFinalizer(() => runtime.runtime.disposeEffect), [scope]),
+        Scope.Scope,
+        scope,
+    ))
 
-const ProviderInner = <R, ER>(
+    return React.createElement(runtime.context, { value: effectRuntime }, children)
-    { runtime, promise, children }: ProviderInnerProps<R, ER>
+}
-): React.ReactNode => React.createElement(
-    runtime.context,
-    { value: React.use(promise) },
-    children,
-)

packages/effect-fc/src/Result.ts

@@ -0,0 +1,269 @@
+import { Cause, Context, Data, Effect, Equal, Exit, type Fiber, Hash, Layer, Match, Pipeable, Predicate, PubSub, pipe, 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")
+export type ResultTypeId = typeof ResultTypeId
+
+export type Result<A, E = never, P = never> = (
+    | Initial
+    | Running<P>
+    | Final<A, E, P>
+)
+
+// biome-ignore lint/complexity/noBannedTypes: "{}" is relevant here
+export type Final<A, E = never, P = never> = (Success<A> | Failure<E>) & ({} | Flags<P>)
+export type Flags<P = never> = WillFetch | WillRefresh | Refreshing<P>
+
+export declare namespace Result {
+    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
+}
+
+export declare namespace Flags {
+    export type Keys = keyof WillFetch & WillRefresh & Refreshing<any>
+}
+
+export interface Initial extends ResultPrototype {
+    readonly _tag: "Initial"
+}
+
+export interface Running<P = never> extends ResultPrototype {
+    readonly _tag: "Running"
+    readonly progress: P
+}
+
+export interface Success<A> extends ResultPrototype {
+    readonly _tag: "Success"
+    readonly value: A
+}
+
+export interface Failure<E = never> extends ResultPrototype {
+    readonly _tag: "Failure"
+    readonly cause: Cause.Cause<E>
+}
+
+export interface WillFetch {
+    readonly _flag: "WillFetch"
+}
+
+export interface WillRefresh {
+    readonly _flag: "WillRefresh"
+}
+
+export interface Refreshing<P = never> {
+    readonly _flag: "Refreshing"
+    readonly progress: P
+}
+
+
+export interface ResultPrototype extends Pipeable.Pipeable, Equal.Equal {
+    readonly [ResultTypeId]: ResultTypeId
+}
+
+export const ResultPrototype: ResultPrototype = Object.freeze({
+    ...Pipeable.Prototype,
+    [ResultTypeId]: ResultTypeId,
+
+    [Equal.symbol](this: Result<any, any, any>, that: Result<any, any, any>): boolean {
+        if (this._tag !== that._tag || (this as Flags)._flag !== (that as Flags)._flag)
+            return false
+        if (hasRefreshingFlag(this) && !Equal.equals(this.progress, (that as Refreshing<any>).progress))
+            return false
+        return Match.value(this).pipe(
+            Match.tag("Initial", () => true),
+            Match.tag("Running", self => Equal.equals(self.progress, (that as Running<any>).progress)),
+            Match.tag("Success", self => Equal.equals(self.value, (that as Success<any>).value)),
+            Match.tag("Failure", self => Equal.equals(self.cause, (that as Failure<any>).cause)),
+            Match.exhaustive,
+        )
+    },
+
+    [Hash.symbol](this: Result<any, any, any>): number {
+        return pipe(Hash.string(this._tag),
+            tagHash => Match.value(this).pipe(
+                Match.tag("Initial", () => tagHash),
+                Match.tag("Running", self => Hash.combine(Hash.hash(self.progress))(tagHash)),
+                Match.tag("Success", self => Hash.combine(Hash.hash(self.value))(tagHash)),
+                Match.tag("Failure", self => Hash.combine(Hash.hash(self.cause))(tagHash)),
+                Match.exhaustive,
+            ),
+            Hash.combine(Hash.hash((this as Flags)._flag)),
+            hash => hasRefreshingFlag(this)
+                ? Hash.combine(Hash.hash(this.progress))(hash)
+                : hash,
+            Hash.cached(this),
+        )
+    },
+} as const)
+
+
+export const isResult = (u: unknown): u is Result<unknown, unknown, unknown> => Predicate.hasProperty(u, ResultTypeId)
+export const isFinal = (u: unknown): u is Final<unknown, unknown, unknown> => isResult(u) && (isSuccess(u) || isFailure(u))
+export const isInitial = (u: unknown): u is Initial => isResult(u) && u._tag === "Initial"
+export const isRunning = (u: unknown): u is Running<unknown> => isResult(u) && u._tag === "Running"
+export const isSuccess = (u: unknown): u is Success<unknown> => isResult(u) && u._tag === "Success"
+export const isFailure = (u: unknown): u is Failure<unknown> => isResult(u) && u._tag === "Failure"
+export const hasFlag = (u: unknown): u is Flags => isResult(u) && Predicate.hasProperty(u, "_flag")
+export const hasWillFetchFlag = (u: unknown): u is WillFetch => isResult(u) && Predicate.hasProperty(u, "_flag") && u._flag === "WillFetch"
+export const hasWillRefreshFlag = (u: unknown): u is WillRefresh => isResult(u) && Predicate.hasProperty(u, "_flag") && u._flag === "WillRefresh"
+export const hasRefreshingFlag = (u: unknown): u is Refreshing<unknown> => isResult(u) && Predicate.hasProperty(u, "_flag") && u._flag === "Refreshing"
+
+export const initial: {
+    (): Initial
+    <A, E = never, P = never>(): Result<A, E, P>
+} = (): Initial => Object.setPrototypeOf({ _tag: "Initial" }, ResultPrototype)
+export const running = <P = never>(progress?: P): Running<P> => Object.setPrototypeOf({ _tag: "Running", progress }, ResultPrototype)
+export const succeed = <A>(value: A): Success<A> => Object.setPrototypeOf({ _tag: "Success", value }, ResultPrototype)
+export const fail = <E>(cause: Cause.Cause<E> ): Failure<E> => Object.setPrototypeOf({ _tag: "Failure", cause }, ResultPrototype)
+
+export const willFetch = <R extends Final<any, any, any>>(
+    result: R
+): Omit<R, keyof Flags.Keys> & WillFetch => Object.setPrototypeOf(
+    Object.assign({}, result, { _flag: "WillFetch" }),
+    Object.getPrototypeOf(result),
+)
+
+export const willRefresh = <R extends Final<any, any, any>>(
+    result: R
+): Omit<R, keyof Flags.Keys> & WillRefresh => Object.setPrototypeOf(
+    Object.assign({}, result, { _flag: "WillRefresh" }),
+    Object.getPrototypeOf(result),
+)
+
+export const refreshing = <R extends Final<any, any, any>, P = never>(
+    result: R,
+    progress?: P,
+): Omit<R, keyof Flags.Keys> & Refreshing<P> => Object.setPrototypeOf(
+    Object.assign({}, result, { _flag: "Refreshing", progress }),
+    Object.getPrototypeOf(result),
+)
+
+export const fromExit: {
+    <A, E>(exit: Exit.Success<A, E>): Success<A>
+    <A, E>(exit: Exit.Failure<A, E>): Failure<E>
+    <A, E>(exit: Exit.Exit<A, E>): Success<A> | Failure<E>
+} = exit => (exit._tag === "Success" ? succeed(exit.value) : fail(exit.cause)) as any
+
+export const toExit: {
+    <A>(self: Success<A>): Exit.Success<A, never>
+    <E>(self: Failure<E>): Exit.Failure<never, E>
+    <A, E, P>(self: Final<A, E, P>): Exit.Exit<A, E>
+    <A, E, P>(self: Result<A, E, P>): Exit.Exit<A, E | Cause.NoSuchElementException>
+} = <A, E, P>(self: Result<A, E, P>): any => {
+    switch (self._tag) {
+        case "Success":
+            return Exit.succeed(self.value)
+        case "Failure":
+            return Exit.failCause(self.cause)
+        default:
+            return Exit.fail(new Cause.NoSuchElementException())
+    }
+}
+
+
+export interface Progress<P = never> {
+    readonly progress: Lens.Lens<P, PreviousResultNotRunningNorRefreshing, never, never, never>
+}
+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 makeProgressLayer = <A, E, P = never>(
+    state: Lens.Lens<Result<A, E, P>, never, never, never, never>
+): Layer.Layer<Progress<P> | Progress<never>, never, never> => Layer.succeed(
+    Progress<P>() as Context.Tag<Progress<P> | Progress<never>, Progress<P> | Progress<never>>,
+    {
+        progress: state.pipe(
+            Lens.mapEffect(
+                a => (isRunning(a) || hasRefreshingFlag(a))
+                    ? Effect.succeed(a)
+                    : Effect.fail(new PreviousResultNotRunningNorRefreshing({ previous: a })),
+                (_, b) => Effect.succeed(b),
+            ),
+            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<R, P> = Exclude<R, Progress<P> | Progress<never>>
+
+    export interface Options<A, E, P> {
+        readonly initial?: Initial | Final<A, E, P>
+        readonly initialProgress?: P
+    }
+}
+
+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.fn.Return<
+    readonly [result: Subscribable.Subscribable<Result<A, E, P>, never, never>, fiber: Fiber.Fiber<A, E>],
+    never,
+    Scope.Scope | unsafeForkEffect.OutputContext<R, P>
+> {
+    const ref = (yield* SynchronizedRef.make(
+        options?.initial ?? initial<A, E, P>()
+    )) as Lens.SynchronizedRefLensImpl.SynchronizedRefWithInternals<Result<A, E, P>>
+    const pubsub = yield* PubSub.unbounded<Result<A, E, P>>()
+
+    const state = Lens.make({
+        get: Ref.get(ref.ref),
+        get changes() {
+            return Stream.unwrapScoped(Effect.map(
+                Effect.all([Ref.get(ref.ref), Stream.fromPubSub(pubsub, { scoped: true })]),
+                ([latest, stream]) => Stream.concat(Stream.make(latest), stream),
+            ))
+        },
+        commit: value => Effect.zipLeft(
+            Ref.set(ref.ref, value),
+            PubSub.publish(pubsub, value),
+        ),
+        lock: Effect.succeed(ref.withLock),
+    })
+
+    const fiber = yield* Effect.gen(function*() {
+        yield* Lens.set(
+            state,
+            (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<R, P> = unsafeForkEffect.OutputContext<R, P>
+    export interface Options<A, E, P> extends unsafeForkEffect.Options<A, E, P> {}
+}
+
+export const forkEffect: {
+    <A, E, R, P = never>(
+        effect: Effect.Effect<A, E, forkEffect.InputContext<R, NoInfer<P>>>,
+        options?: forkEffect.Options<NoInfer<A>, NoInfer<E>, P>,
+    ): Effect.Effect<
+        readonly [result: Subscribable.Subscribable<Result<A, E, P>, never, never>, fiber: Fiber.Fiber<A, E>],
+        never,
+        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/Stream.ts

@@ -1,9 +1,9 @@
-import { Effect, Equivalence, Option, PubSub, Ref, type Scope, Stream } from "effect"
+import { Effect, Equivalence, Option, Stream } from "effect"
 import * as React from "react"
 import * as Component from "./Component.js"
 
 
-export const useStream: {
+export const use: {
     <A, E, R>(
         stream: Stream.Stream<A, E, R>
     ): Effect.Effect<Option.Option<A>, never, R>
@@ -30,29 +30,4 @@ export const useStream: {
     return reactStateValue as Option.Some<A>
 })
 
-export const useStreamFromReactiveValues: {
-    <const A extends React.DependencyList>(
-        values: A
-    ): Effect.Effect<Stream.Stream<A>, never, Scope.Scope>
-} = Effect.fnUntraced(function* <const A extends React.DependencyList>(values: A) {
-    const { latest, pubsub, stream } = yield* Component.useOnMount(() => Effect.Do.pipe(
-        Effect.bind("latest", () => Ref.make(values)),
-        Effect.bind("pubsub", () => Effect.acquireRelease(PubSub.unbounded<A>(), PubSub.shutdown)),
-        Effect.let("stream", ({ latest, pubsub }) => latest.pipe(
-            Effect.flatMap(a => Effect.map(
-                Stream.fromPubSub(pubsub, { scoped: true }),
-                s => Stream.concat(Stream.make(a), s),
-            )),
-            Stream.unwrapScoped,
-        )),
-    ))
-
-    yield* Component.useReactEffect(() => Ref.set(latest, values).pipe(
-        Effect.andThen(PubSub.publish(pubsub, values)),
-        Effect.unlessEffect(PubSub.isShutdown(pubsub)),
-    ), values)
-
-    return stream
-})
-
 export * from "effect/Stream"

packages/effect-fc/src/SubmittableForm.ts

@@ -0,0 +1,220 @@
+import { Array, Cause, Chunk, type Context, Effect, Fiber, flow, identity, Option, ParseResult, Pipeable, Predicate, Schema, type Scope, SubscriptionRef } from "effect"
+import * as Form from "./Form.js"
+import * as Lens from "./Lens.js"
+import * as Mutation from "./Mutation.js"
+import * as Result from "./Result.js"
+import * as Subscribable from "./Subscribable.js"
+
+
+export const SubmittableFormTypeId: unique symbol = Symbol.for("@effect-fc/Form/SubmittableForm")
+export type SubmittableFormTypeId = typeof SubmittableFormTypeId
+
+export interface SubmittableForm<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.Form<readonly [], A, I, never, never> {
+    readonly [SubmittableFormTypeId]: SubmittableFormTypeId
+
+    readonly schema: Schema.Schema<A, I, R>
+    readonly context: Context.Context<Scope.Scope | R>
+    readonly mutation: Mutation.Mutation<
+        readonly [value: A, form: SubmittableForm<A, I, R, unknown, unknown, unknown>],
+        MA, ME, MR, MP
+    >
+    readonly validationFiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>, never, never>
+
+    readonly run: Effect.Effect<void>
+    readonly submit: Effect.Effect<Option.Option<Result.Final<MA, ME, MP>>, Cause.NoSuchElementException>
+}
+
+export class SubmittableFormImpl<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 SubmittableForm<A, I, R, MA, ME, MR, MP> {
+    readonly [Form.FormTypeId]: Form.FormTypeId = Form.FormTypeId
+    readonly [SubmittableFormTypeId]: SubmittableFormTypeId = SubmittableFormTypeId
+
+    readonly path = [] as const
+
+    readonly encodedValue: Lens.Lens<I, never, never, never, never>
+    readonly isValidating: Subscribable.Subscribable<boolean, never, never>
+    readonly canCommit: Subscribable.Subscribable<boolean, never, never>
+    readonly isCommitting: Subscribable.Subscribable<boolean, never, never>
+
+    constructor(
+        readonly schema: Schema.Schema<A, I, R>,
+        readonly context: Context.Context<Scope.Scope | R>,
+        readonly mutation: Mutation.Mutation<
+            readonly [value: A, form: SubmittableForm<A, I, R, unknown, unknown, unknown>],
+            MA, ME, MR, MP
+        >,
+        readonly value: Lens.Lens<Option.Option<A>, never, never, never, never>,
+        readonly internalEncodedValue: Lens.Lens<I, never, never, never, never>,
+        readonly issues: Lens.Lens<readonly ParseResult.ArrayFormatterIssue[], never, never, never, never>,
+        readonly validationFiber: Lens.Lens<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>, never, never, never, never>,
+
+        readonly runSemaphore: Effect.Semaphore,
+    ) {
+        super()
+
+        this.encodedValue = Effect.all([
+            Effect.succeed(this),
+            Effect.succeed(Lens.asLensImpl(this.internalEncodedValue)),
+        ]).pipe(
+            Effect.map(([self, parent]) => Lens.make({
+                get: parent.get,
+                get changes() { return parent.changes },
+                commit: a => Effect.andThen(
+                    Effect.flatMap(
+                        parent.resolve,
+                        resolved => resolved.commit(Effect.succeed(a)),
+                    ),
+                    self.synchronizeEncodedValue(a),
+                ),
+                lock: parent.lock,
+            })),
+            Lens.unwrap,
+        )
+        this.isValidating = Effect.succeed(this).pipe(
+            Effect.map(self => Subscribable.map(self.validationFiber, Option.isSome)),
+            Subscribable.unwrap,
+        )
+        this.canCommit = Effect.succeed(this).pipe(
+            Effect.map(self => Subscribable.map(
+                Subscribable.zipLatestAll(self.value, self.issues, self.validationFiber, self.mutation.result),
+                ([value, issues, validationFiber, result]) => (
+                    Option.isSome(value) &&
+                    Array.isEmptyReadonlyArray(issues) &&
+                    Option.isNone(validationFiber) &&
+                    !(Result.isRunning(result) || Result.hasRefreshingFlag(result))
+                ),
+            )),
+            Subscribable.unwrap,
+        )
+        this.isCommitting = Effect.succeed(this).pipe(
+            Effect.map(self => Subscribable.map(
+                self.mutation.result,
+                result => Result.isRunning(result) || Result.hasRefreshingFlag(result),
+            )),
+            Subscribable.unwrap,
+        )
+    }
+
+    synchronizeEncodedValue(encodedValue: I): Effect.Effect<void, never, never> {
+        return Lens.get(this.validationFiber).pipe(
+            Effect.andThen(Option.match({
+                onSome: Fiber.interrupt,
+                onNone: () => Effect.void,
+            })),
+            Effect.andThen(Effect.forkScoped(
+                Effect.ensuring(
+                    Schema.decode(this.schema, { errors: "all" })(encodedValue),
+                    Lens.set(this.validationFiber, Option.none()),
+                )
+            )),
+            Effect.tap(fiber => Lens.set(this.validationFiber, Option.some(fiber))),
+            Effect.flatMap(Fiber.join),
+
+            Effect.tap(() => Lens.set(this.issues, Array.empty())),
+            Effect.flatMap(value => Lens.set(this.value, Option.some(value))),
+            Effect.catchIf(
+                ParseResult.isParseError,
+                flow(
+                    ParseResult.ArrayFormatter.formatError,
+                    Effect.flatMap(v => Lens.set(this.issues, v)),
+                ),
+            ),
+
+            Effect.provide(this.context),
+        )
+    }
+
+    get run(): Effect.Effect<void, never, never> {
+        return Lens.get(this.encodedValue).pipe(
+            Effect.flatMap(v => Schema.decode(this.schema)(v)),
+            Effect.option,
+            Effect.flatMap(v => Lens.set(this.value, v)),
+            Effect.provide(this.context),
+            this.runSemaphore.withPermits(1),
+        )
+    }
+
+    get submit(): Effect.Effect<Option.Option<Result.Final<MA, ME, MP>>, Cause.NoSuchElementException, never> {
+        return Lens.get(this.value).pipe(
+            Effect.flatMap(identity),
+            Effect.flatMap(value => this.submitValue(value)),
+        )
+    }
+
+    submitValue(value: A): Effect.Effect<Option.Option<Result.Final<MA, ME, MP>>, never, never> {
+        return Effect.whenEffect(
+            Effect.tap(
+                this.mutation.mutate([value, this as any]),
+                result => Result.isFailure(result)
+                    ? Option.match(
+                        Chunk.findFirst(
+                            Cause.failures(result.cause as Cause.Cause<ParseResult.ParseError>),
+                            e => e._tag === "ParseError",
+                        ),
+                        {
+                            onSome: e => Effect.flatMap(
+                                ParseResult.ArrayFormatter.formatError(e),
+                                v => Lens.set(this.issues, v),
+                            ),
+                            onNone: () => Effect.void,
+                        },
+                    )
+                    : Effect.void
+            ),
+            this.canCommit.get,
+        )
+    }
+}
+
+
+export const isSubmittableForm = (u: unknown): u is SubmittableForm<unknown, unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, SubmittableFormTypeId)
+
+
+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: SubmittableForm<NoInfer<A>, NoInfer<I>, NoInfer<R>, unknown, unknown, unknown>],
+        MA, ME, MR, MP
+    > {
+        readonly schema: Schema.Schema<A, I, R>
+        readonly initialEncodedValue: NoInfer<I>
+    }
+}
+
+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<
+    SubmittableForm<A, I, R, MA, ME, Result.forkEffect.OutputContext<MR, MP>, MP>,
+    never,
+    Scope.Scope | R | Result.forkEffect.OutputContext<MR, MP>
+> {
+    return new SubmittableFormImpl(
+        options.schema,
+        yield* Effect.context<Scope.Scope | R>(),
+        yield* Mutation.make(options),
+
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(Option.none<A>())),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(options.initialEncodedValue)),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make<readonly ParseResult.ArrayFormatterIssue[]>(Array.empty())),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, ParseResult.ParseError>>())),
+
+        yield* Effect.makeSemaphore(1),
+    )
+})
+
+export declare namespace service {
+    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 make.Options<A, I, R, MA, ME, MR, MP> {}
+}
+
+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<
+    SubmittableForm<A, I, R, MA, ME, Result.forkEffect.OutputContext<MR, MP>, MP>,
+    never,
+    Scope.Scope | R | Result.forkEffect.OutputContext<MR, MP>
+> => Effect.tap(
+    make(options),
+    form => Effect.forkScoped(form.run),
+)

packages/effect-fc/src/Subscribable.ts

@@ -1,8 +1,11 @@
-import { Effect, Equivalence, pipe, type Scope, 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<
@@ -16,32 +19,35 @@ export const zipLatestAll = <const T extends readonly Subscribable.Subscribable<
     changes: Stream.zipLatestAll(...elements.map(v => v.changes)),
 }) as any
 
-export const useSubscribables: {
+export declare namespace useAll {
-    <const T extends readonly Subscribable.Subscribable<any, any, any>[]>(
+    export type Success<T extends readonly Subscribable.Subscribable<any, any, any>[]> = [T[number]] extends [never]
-        ...elements: T
-    ): Effect.Effect<
-        [T[number]] extends [never]
         ? never
-            : { [K in keyof T]: T[K] extends Subscribable.Subscribable<infer A, infer _E, infer _R> ? A : never },
+        : { [K in keyof T]: T[K] extends Subscribable.Subscribable<infer A, infer _E, infer _R> ? A : never }
+
+    export interface Options<A> {
+        readonly equivalence?: Equivalence.Equivalence<A>
+    }
+}
+
+export const useAll = Effect.fnUntraced(function* <const T extends readonly Subscribable.Subscribable<any, any, any>[]>(
+    elements: T,
+    options?: useAll.Options<useAll.Success<NoInfer<T>>>,
+): Effect.fn.Return<
+    useAll.Success<T>,
     [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) | Scope.Scope
+    [T[number]] extends [never] ? never : T[number] extends Subscribable.Subscribable<infer _A, infer _E, infer R> ? R : never
-    >
+> {
-} = Effect.fnUntraced(function* <const T extends readonly Subscribable.Subscribable<any, any, any>[]>(
-    ...elements: T
-) {
     const [reactStateValue, setReactStateValue] = React.useState(
         yield* Component.useOnMount(() => Effect.all(elements.map(v => v.get)))
     )
 
-    yield* Component.useReactEffect(() => Effect.forkScoped(pipe(
+    yield* Component.useReactEffect(() => Stream.zipLatestAll(...elements.map(ref => ref.changes)).pipe(
-        elements.map(ref => Stream.changesWith(ref.changes, Equivalence.strict())),
+        Stream.changesWith((options?.equivalence as Equivalence.Equivalence<any[]> | undefined) ?? Equivalence.array(Equivalence.strict())),
-        streams => Stream.zipLatestAll(...streams),
         Stream.runForEach(v =>
             Effect.sync(() => setReactStateValue(v))
         ),
-    )), elements)
+        Effect.forkScoped,
+    ), elements)
 
     return reactStateValue as any
 })
-
-export * from "effect/Subscribable"

packages/effect-fc/src/SubscriptionRef.ts

@@ -1,48 +0,0 @@
-import { Effect, Equivalence, Ref, type Scope, Stream, SubscriptionRef } from "effect"
-import * as React from "react"
-import * as Component from "./Component.js"
-import * as SetStateAction from "./SetStateAction.js"
-
-
-export const useSubscriptionRefState: {
-    <A>(
-        ref: SubscriptionRef.SubscriptionRef<A>
-    ): Effect.Effect<readonly [A, React.Dispatch<React.SetStateAction<A>>], never, Scope.Scope>
-} = Effect.fnUntraced(function* <A>(ref: SubscriptionRef.SubscriptionRef<A>) {
-    const [reactStateValue, setReactStateValue] = React.useState(yield* Component.useOnMount(() => ref))
-
-    yield* Component.useReactEffect(() => Effect.forkScoped(
-        Stream.runForEach(
-            Stream.changesWith(ref.changes, Equivalence.strict()),
-            v => Effect.sync(() => setReactStateValue(v)),
-        )
-    ), [ref])
-
-    const setValue = yield* Component.useCallbackSync((setStateAction: React.SetStateAction<A>) =>
-        Effect.andThen(
-            Ref.updateAndGet(ref, prevState => SetStateAction.value(setStateAction, prevState)),
-            v => setReactStateValue(v),
-        ),
-    [ref])
-
-    return [reactStateValue, setValue]
-})
-
-export const useSubscriptionRefFromState: {
-    <A>(state: readonly [A, React.Dispatch<React.SetStateAction<A>>]): Effect.Effect<SubscriptionRef.SubscriptionRef<A>, never, Scope.Scope>
-} = Effect.fnUntraced(function*([value, setValue]) {
-    const ref = yield* Component.useOnChange(() => Effect.tap(
-        SubscriptionRef.make(value),
-        ref => Effect.forkScoped(
-            Stream.runForEach(
-                Stream.changesWith(ref.changes, Equivalence.strict()),
-                v => Effect.sync(() => setValue(v)),
-            )
-        ),
-    ), [setValue])
-
-    yield* Component.useReactEffect(() => Ref.set(ref, value), [value])
-    return ref
-})
-
-export * from "effect/SubscriptionRef"

packages/effect-fc/src/SubscriptionSubRef.ts

@@ -1,186 +0,0 @@
-import { Chunk, Effect, Effectable, Option, Predicate, Readable, Ref, Stream, Subscribable, SubscriptionRef, SynchronizedRef, type Types, type Unify } from "effect"
-import * as PropertyPath from "./PropertyPath.js"
-
-
-export const SubscriptionSubRefTypeId: unique symbol = Symbol.for("effect-fc/SubscriptionSubRef/SubscriptionSubRef")
-export type SubscriptionSubRefTypeId = typeof SubscriptionSubRefTypeId
-
-export interface SubscriptionSubRef<in out A, in out B extends SubscriptionRef.SubscriptionRef<any>>
-extends SubscriptionSubRef.Variance<A, B>, SubscriptionRef.SubscriptionRef<A> {
-    readonly parent: B
-
-    readonly [Unify.typeSymbol]?: unknown
-    readonly [Unify.unifySymbol]?: SubscriptionSubRefUnify<this>
-    readonly [Unify.ignoreSymbol]?: SubscriptionSubRefUnifyIgnore
-}
-
-export declare namespace SubscriptionSubRef {
-    export interface Variance<in out A, in out B> {
-        readonly [SubscriptionSubRefTypeId]: {
-            readonly _A: Types.Invariant<A>
-            readonly _B: Types.Invariant<B>
-        }
-    }
-}
-
-export interface SubscriptionSubRefUnify<A extends { [Unify.typeSymbol]?: any }> extends SubscriptionRef.SubscriptionRefUnify<A> {
-    SubscriptionSubRef?: () => Extract<A[Unify.typeSymbol], SubscriptionSubRef<any, any>>
-}
-
-export interface SubscriptionSubRefUnifyIgnore extends SubscriptionRef.SubscriptionRefUnifyIgnore {
-    SubscriptionRef?: true
-}
-
-
-const refVariance = { _A: (_: any) => _ }
-const synchronizedRefVariance = { _A: (_: any) => _ }
-const subscriptionRefVariance = { _A: (_: any) => _ }
-const subscriptionSubRefVariance = { _A: (_: any) => _, _B: (_: any) => _ }
-
-class SubscriptionSubRefImpl<in out A, in out B extends SubscriptionRef.SubscriptionRef<any>>
-extends Effectable.Class<A> implements SubscriptionSubRef<A, B> {
-    readonly [Readable.TypeId]: Readable.TypeId = Readable.TypeId
-    readonly [Subscribable.TypeId]: Subscribable.TypeId = Subscribable.TypeId
-    readonly [Ref.RefTypeId] = refVariance
-    readonly [SynchronizedRef.SynchronizedRefTypeId] = synchronizedRefVariance
-    readonly [SubscriptionRef.SubscriptionRefTypeId] = subscriptionRefVariance
-    readonly [SubscriptionSubRefTypeId] = subscriptionSubRefVariance
-
-    readonly get: Effect.Effect<A>
-
-    constructor(
-        readonly parent: B,
-        readonly getter: (parentValue: Effect.Effect.Success<B>) => A,
-        readonly setter: (parentValue: Effect.Effect.Success<B>, value: A) => Effect.Effect.Success<B>,
-    ) {
-        super()
-        this.get = Effect.map(this.parent, this.getter)
-    }
-
-    commit() {
-        return this.get
-    }
-
-    get changes(): Stream.Stream<A> {
-        return Stream.unwrap(
-            Effect.map(this.get, a => Stream.concat(
-                Stream.make(a),
-                Stream.map(this.parent.changes, this.getter),
-            ))
-        )
-    }
-
-    modify<C>(f: (a: A) => readonly [C, A]): Effect.Effect<C> {
-        return this.modifyEffect(a => Effect.succeed(f(a)))
-    }
-
-    modifyEffect<C, E, R>(f: (a: A) => Effect.Effect<readonly [C, A], E, R>): Effect.Effect<C, E, R> {
-        return Effect.Do.pipe(
-            Effect.bind("b", (): Effect.Effect<Effect.Effect.Success<B>> => this.parent),
-            Effect.bind("ca", ({ b }) => f(this.getter(b))),
-            Effect.tap(({ b, ca: [, a] }) => SubscriptionRef.set(this.parent, this.setter(b, a))),
-            Effect.map(({ ca: [c] }) => c),
-        )
-    }
-}
-
-
-export const isSubscriptionSubRef = (u: unknown): u is SubscriptionSubRef<unknown, SubscriptionRef.SubscriptionRef<unknown>> => Predicate.hasProperty(u, SubscriptionSubRefTypeId)
-
-export const makeFromGetSet = <A, B extends SubscriptionRef.SubscriptionRef<any>>(
-    parent: B,
-    options: {
-        readonly get: (parentValue: Effect.Effect.Success<B>) => A
-        readonly set: (parentValue: Effect.Effect.Success<B>, value: A) => Effect.Effect.Success<B>
-    },
-): SubscriptionSubRef<A, B> => new SubscriptionSubRefImpl(parent, options.get, options.set)
-
-export const makeFromPath = <
-    B extends SubscriptionRef.SubscriptionRef<any>,
-    const P extends PropertyPath.Paths<Effect.Effect.Success<B>>,
->(
-    parent: B,
-    path: P,
-): SubscriptionSubRef<PropertyPath.ValueFromPath<Effect.Effect.Success<B>, P>, B> => new SubscriptionSubRefImpl(
-    parent,
-    parentValue => Option.getOrThrow(PropertyPath.get(parentValue, path)),
-    (parentValue, value) => Option.getOrThrow(PropertyPath.immutableSet(parentValue, path, value)),
-)
-
-export const makeFromChunkIndex: {
-    <B extends SubscriptionRef.SubscriptionRef<Chunk.NonEmptyChunk<any>>>(
-        parent: B,
-        index: number,
-    ): SubscriptionSubRef<
-        Effect.Effect.Success<B> extends Chunk.NonEmptyChunk<infer A> ? A : never,
-        B
-    >
-    <B extends SubscriptionRef.SubscriptionRef<Chunk.Chunk<any>>>(
-        parent: B,
-        index: number,
-    ): SubscriptionSubRef<
-        Effect.Effect.Success<B> extends Chunk.Chunk<infer A> ? A : never,
-        B
-    >
-} = (
-    parent: SubscriptionRef.SubscriptionRef<Chunk.Chunk<any>>,
-    index: number,
-) => new SubscriptionSubRefImpl(
-    parent,
-    parentValue => Chunk.unsafeGet(parentValue, index),
-    (parentValue, value) => Chunk.replace(parentValue, index, value),
-) as any
-
-export const makeFromChunkFindFirst: {
-    <B extends SubscriptionRef.SubscriptionRef<Chunk.NonEmptyChunk<any>>>(
-        parent: B,
-        findFirstPredicate: Predicate.Predicate<Effect.Effect.Success<B> extends Chunk.NonEmptyChunk<infer A> ? A : never>,
-    ): SubscriptionSubRef<
-        Effect.Effect.Success<B> extends Chunk.NonEmptyChunk<infer A> ? A : never,
-        B
-    >
-    <B extends SubscriptionRef.SubscriptionRef<Chunk.Chunk<any>>>(
-        parent: B,
-        findFirstPredicate: Predicate.Predicate<Effect.Effect.Success<B> extends Chunk.Chunk<infer A> ? A : never>,
-    ): SubscriptionSubRef<
-        Effect.Effect.Success<B> extends Chunk.Chunk<infer A> ? A : never,
-        B
-    >
-} = (
-    parent: SubscriptionRef.SubscriptionRef<Chunk.Chunk<never>>,
-    findFirstPredicate: Predicate.Predicate.Any,
-) => new SubscriptionSubRefImpl(
-    parent,
-    parentValue => Option.getOrThrow(Chunk.findFirst(parentValue, findFirstPredicate)),
-    (parentValue, value) => Option.getOrThrow(Option.andThen(
-        Chunk.findFirstIndex(parentValue, findFirstPredicate),
-        index => Chunk.replace(parentValue, index, value),
-    )),
-) as any
-
-export const makeFromChunkFindLast: {
-    <B extends SubscriptionRef.SubscriptionRef<Chunk.NonEmptyChunk<any>>>(
-        parent: B,
-        findLastPredicate: Predicate.Predicate<Effect.Effect.Success<B> extends Chunk.NonEmptyChunk<infer A> ? A : never>,
-    ): SubscriptionSubRef<
-        Effect.Effect.Success<B> extends Chunk.NonEmptyChunk<infer A> ? A : never,
-        B
-    >
-    <B extends SubscriptionRef.SubscriptionRef<Chunk.Chunk<any>>>(
-        parent: B,
-        findLastPredicate: Predicate.Predicate<Effect.Effect.Success<B> extends Chunk.Chunk<infer A> ? A : never>,
-    ): SubscriptionSubRef<
-        Effect.Effect.Success<B> extends Chunk.Chunk<infer A> ? A : never,
-        B
-    >
-} = (
-    parent: SubscriptionRef.SubscriptionRef<Chunk.Chunk<never>>,
-    findLastPredicate: Predicate.Predicate.Any,
-) => new SubscriptionSubRefImpl(
-    parent,
-    parentValue => Option.getOrThrow(Chunk.findLast(parentValue, findLastPredicate)),
-    (parentValue, value) => Option.getOrThrow(Option.andThen(
-        Chunk.findLastIndex(parentValue, findLastPredicate),
-        index => Chunk.replace(parentValue, index, value),
-    )),
-) as any

packages/effect-fc/src/SynchronizedForm.ts

@@ -0,0 +1,223 @@
+import { Array, type Context, Effect, Equal, Fiber, flow, Option, ParseResult, Pipeable, Predicate, Schema, type Scope, Stream, SubscriptionRef } from "effect"
+import * as Form from "./Form.js"
+import * as Lens from "./Lens.js"
+import * as Subscribable from "./Subscribable.js"
+
+
+export const SynchronizedFormTypeId: unique symbol = Symbol.for("@effect-fc/Form/SynchronizedForm")
+export type SynchronizedFormTypeId = typeof SynchronizedFormTypeId
+
+export interface SynchronizedForm<
+    in out A,
+    in out I = A,
+    in out R = never,
+    in out TER = never,
+    in out TEW = never,
+    in out TRR = never,
+    in out TRW = never,
+> extends Form.Form<readonly [], A, I, TER, TER | TEW> {
+    readonly [SynchronizedFormTypeId]: SynchronizedFormTypeId
+
+    readonly schema: Schema.Schema<A, I, R>
+    readonly context: Context.Context<Scope.Scope | R | TRR | TRW>
+    readonly target: Lens.Lens<A, TER, TEW, TRR, TRW>
+    readonly validationFiber: Subscribable.Subscribable<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>, never, never>
+
+    readonly run: Effect.Effect<void, TER>
+}
+
+export class SynchronizedFormImpl<
+    in out A,
+    in out I = A,
+    in out R = never,
+    in out TER = never,
+    in out TEW = never,
+    in out TRR = never,
+    in out TRW = never,
+> extends Pipeable.Class() implements SynchronizedForm<A, I, R, TER, TEW, TRR, TRW> {
+    readonly [Form.FormTypeId]: Form.FormTypeId = Form.FormTypeId
+    readonly [SynchronizedFormTypeId]: SynchronizedFormTypeId = SynchronizedFormTypeId
+
+    readonly path = [] as const
+
+    readonly value: Subscribable.Subscribable<Option.Option<A>, never, never>
+    readonly encodedValue: Lens.Lens<I, TER, TER | TEW, never, never>
+    readonly isValidating: Subscribable.Subscribable<boolean, never, never>
+    readonly canCommit: Subscribable.Subscribable<boolean, never, never>
+
+    constructor(
+        readonly schema: Schema.Schema<A, I, R>,
+        readonly context: Context.Context<Scope.Scope | R | TRR | TRW>,
+        readonly target: Lens.Lens<A, TER, TEW, TRR, TRW>,
+
+        readonly internalEncodedValue: Lens.Lens<I, never, never, never, never>,
+        readonly issues: Lens.Lens<readonly ParseResult.ArrayFormatterIssue[], never, never, never, never>,
+        readonly validationFiber: Lens.Lens<Option.Option<Fiber.Fiber<A, ParseResult.ParseError>>, never, never, never, never>,
+        readonly isCommitting: Lens.Lens<boolean, never, never>,
+
+        readonly runSemaphore: Effect.Semaphore,
+    ) {
+        super()
+
+        this.value = Effect.succeed(this).pipe(
+            Effect.map(self => Subscribable.make({
+                get: Effect.provide(Effect.option(self.target.get), self.context),
+                get changes() {
+                    return Stream.provideContext(
+                        self.target.changes.pipe(
+                            Stream.map(Option.some),
+                            Stream.catchAll(() => Stream.make(Option.none())),
+                        ),
+                        self.context,
+                    )
+                },
+            })),
+            Subscribable.unwrap,
+        )
+        this.encodedValue = Effect.all([
+            Effect.succeed(this),
+            Effect.succeed(Lens.asLensImpl(this.internalEncodedValue)),
+        ]).pipe(
+            Effect.map(([self, parent]) => Lens.make<I, TER, TER | TEW, never, never>({
+                get: parent.get,
+                get changes() { return parent.changes },
+                commit: a => Effect.andThen(
+                    Effect.flatMap(
+                        parent.resolve,
+                        resolved => resolved.commit(Effect.succeed(a)),
+                    ),
+                    self.synchronizeEncodedValue(a),
+                ),
+                lock: parent.lock,
+            })),
+            Lens.unwrap,
+        )
+        this.isValidating = Effect.succeed(this).pipe(
+            Effect.map(self => Subscribable.map(self.validationFiber, Option.isSome)),
+            Subscribable.unwrap,
+        )
+        this.canCommit = Effect.succeed(this).pipe(
+            Effect.map(self => Subscribable.map(
+                Subscribable.zipLatestAll(self.issues, self.validationFiber, self.isCommitting),
+                ([issues, validationFiber, isCommitting]) => (
+                    Array.isEmptyReadonlyArray(issues) &&
+                    Option.isNone(validationFiber) &&
+                    !isCommitting
+                ),
+            )),
+            Subscribable.unwrap,
+        )
+    }
+
+    synchronizeEncodedValue(encodedValue: I): Effect.Effect<void, TER | TEW, never> {
+        return Lens.get(this.validationFiber).pipe(
+            Effect.andThen(Option.match({
+                onSome: Fiber.interrupt,
+                onNone: () => Effect.void,
+            })),
+            Effect.andThen(Effect.forkScoped(
+                Effect.ensuring(
+                    Schema.decode(this.schema, { errors: "all" })(encodedValue),
+                    Lens.set(this.validationFiber, Option.none()),
+                )
+            )),
+            Effect.tap(fiber => Lens.set(this.validationFiber, Option.some(fiber))),
+            Effect.flatMap(Fiber.join),
+
+            Effect.flatMap(value => Effect.ensuring(
+                Lens.set(this.isCommitting, true).pipe(
+                    Effect.andThen(Lens.set(this.issues, Array.empty())),
+                    Effect.andThen(Lens.set(this.target, value)),
+                ),
+                Lens.set(this.isCommitting, false),
+            )),
+            Effect.catchIf(
+                ParseResult.isParseError,
+                flow(
+                    ParseResult.ArrayFormatter.formatError,
+                    Effect.flatMap(v => Lens.set(this.issues, v)),
+                ),
+            ),
+
+            Effect.provide(this.context),
+        )
+    }
+
+    get run(): Effect.Effect<void, TER, never> {
+        return this.runSemaphore.withPermits(1)(Effect.provide(
+            Stream.runForEach(
+                Stream.drop(this.target.changes, 1),
+                targetValue => Schema.encode(this.schema, { errors: "all" })(targetValue).pipe(
+                    Effect.flatMap(encodedValue => Effect.whenEffect(
+                        Effect.andThen(
+                            Lens.set(this.issues, Array.empty()),
+                            Lens.set(this.internalEncodedValue, encodedValue),
+                        ),
+                        Effect.map(
+                            Lens.get(this.internalEncodedValue),
+                            currentEncodedValue => !Equal.equals(encodedValue, currentEncodedValue),
+                        ),
+                    )),
+                    Effect.ignore,
+                ),
+            ),
+            this.context,
+        ))
+    }
+}
+
+
+export const isSynchronizedForm = (u: unknown): u is SynchronizedForm<unknown, unknown, unknown, unknown, unknown, unknown, unknown> => Predicate.hasProperty(u, SynchronizedFormTypeId)
+
+
+export declare namespace make {
+    export interface Options<in out A, in out I = A, in out R = never, in out TER = never, in out TEW = never, in out TRR = never, in out TRW = never> {
+        readonly schema: Schema.Schema<A, I, R>
+        readonly target: Lens.Lens<A, TER, TEW, TRR, TRW>
+        readonly initialEncodedValue?: NoInfer<I>
+    }
+}
+
+export const make = Effect.fnUntraced(function* <A, I = A, R = never, TER = never, TEW = never, TRR = never, TRW = never>(
+    options: make.Options<A, I, R, TER, TEW, TRR, TRW>
+): Effect.fn.Return<
+    SynchronizedForm<A, I, R, TER, TEW, TRR, TRW>,
+    ParseResult.ParseError | TER,
+    Scope.Scope | R | TRR | TRW
+> {
+    const initialEncodedValue = options.initialEncodedValue !== undefined
+        ? options.initialEncodedValue
+        : yield* Effect.flatMap(
+            Lens.get(options.target),
+            Schema.encode(options.schema, { errors: "all" }),
+        )
+
+    return new SynchronizedFormImpl(
+        options.schema,
+        yield* Effect.context<Scope.Scope | R | TRR | TRW>(),
+        options.target,
+
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(initialEncodedValue)),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make<readonly ParseResult.ArrayFormatterIssue[]>(Array.empty())),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(Option.none<Fiber.Fiber<A, ParseResult.ParseError>>())),
+        Lens.fromSubscriptionRef(yield* SubscriptionRef.make(false)),
+
+        yield* Effect.makeSemaphore(1),
+    )
+})
+
+export declare namespace service {
+    export interface Options<in out A, in out I = A, in out R = never, in out TER = never, in out TEW = never, in out TRR = never, in out TRW = never>
+    extends make.Options<A, I, R, TER, TEW, TRR, TRW> {}
+}
+
+export const service = <A, I = A, R = never, TER = never, TEW = never, TRR = never, TRW = never>(
+    options: service.Options<A, I, R, TER, TEW, TRR, TRW>
+): Effect.Effect<
+    SynchronizedForm<A, I, R, TER, TEW, TRR, TRW>,
+    ParseResult.ParseError | TER,
+    Scope.Scope | R | TRR | TRW
+> => Effect.tap(
+    make(options),
+    form => Effect.forkScoped(form.run),
+)

packages/effect-fc/src/index.ts

@@ -1,11 +1,17 @@
 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 PropertyPath from "./PropertyPath.js"
+export * as Mutation from "./Mutation.js"
+export * as PubSub from "./PubSub.js"
+export * as Query from "./Query.js"
+export * as QueryClient from "./QueryClient.js"
 export * as ReactRuntime from "./ReactRuntime.js"
+export * as Result from "./Result.js"
 export * as SetStateAction from "./SetStateAction.js"
 export * as Stream from "./Stream.js"
+export * as SubmittableForm from "./SubmittableForm.js"
 export * as Subscribable from "./Subscribable.js"
-export * as SubscriptionRef from "./SubscriptionRef.js"
+export * as SynchronizedForm from "./SynchronizedForm.js"
-export * as SubscriptionSubRef from "./SubscriptionSubRef.js"

packages/effect-fc/test/Component.test.tsx

@@ -0,0 +1,354 @@
+import { render, screen, waitFor } from "@testing-library/react"
+import { Context, Effect, Layer } from "effect"
+import * as React from "react"
+import { afterEach, describe, expect, it, vi } from "vitest"
+import * as Component from "../src/Component.js"
+import * as ReactRuntime from "../src/ReactRuntime.js"
+
+
+class ValueService extends Context.Tag("ValueService")<ValueService, { readonly value: string }>() {}
+
+afterEach(() => {
+    vi.useRealTimers()
+})
+
+describe("Component", () => {
+    it("runs useOnMount only once across rerenders", async () => {
+        const onMount = vi.fn(() => Effect.succeed("mounted"))
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+        const Probe = Component.makeUntraced("UseOnMountProbe")(function*() {
+            const value = yield* Component.useOnMount(onMount)
+            return <div>{value}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("mounted")
+        expect(onMount).toHaveBeenCalledTimes(1)
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+        expect(await screen.findByText("mounted")).toBeTruthy()
+        expect(onMount).toHaveBeenCalledTimes(1)
+
+        view.unmount()
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+
+    it("recomputes useOnChange only when dependencies change", async () => {
+        const onChange = vi.fn((value: number) => Effect.succeed(`value:${value}`))
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+        const Probe = Component.makeUntraced("UseOnChangeProbe")(function*(props: { readonly value: number }) {
+            const result = yield* Component.useOnChange(() => onChange(props.value), [props.value], {
+                finalizerExecutionDebounce: 0,
+            })
+
+            return <div>{result}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value={1} />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("value:1")
+        expect(onChange).toHaveBeenCalledTimes(1)
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value={1} />
+            </runtime.context.Provider>
+        )
+
+        expect(await screen.findByText("value:1")).toBeTruthy()
+        expect(onChange).toHaveBeenCalledTimes(1)
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value={2} />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("value:2")
+        expect(onChange).toHaveBeenCalledTimes(2)
+
+        view.unmount()
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+
+    it("closes the previous scope on dependency changes and unmount", async () => {
+        const cleanup = vi.fn()
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+        const Probe = Component.makeUntraced("ScopeCleanupProbe")(function*(props: { readonly value: string }) {
+            const result = yield* Component.useOnChange(
+                () => Effect.gen(function*() {
+                    yield* Effect.addFinalizer(() => Effect.sync(() => cleanup(props.value)))
+                    return props.value
+                }),
+                [props.value],
+                { finalizerExecutionDebounce: 0 },
+            )
+
+            return <div>{result}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value="first" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first")
+        expect(cleanup).not.toHaveBeenCalled()
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value="second" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("second")
+        await waitFor(() => expect(cleanup).toHaveBeenCalledWith("first"))
+        expect(cleanup).toHaveBeenCalledTimes(1)
+
+        view.unmount()
+
+        await waitFor(() => expect(cleanup).toHaveBeenCalledWith("second"))
+        expect(cleanup).toHaveBeenCalledTimes(2)
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+
+    it("runs useReactEffect setup and cleanup when dependencies change", async () => {
+        const lifecycle = vi.fn<(message: string) => void>()
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+        const Probe = Component.makeUntraced("UseReactEffectProbe")(function*(props: { readonly value: string }) {
+            yield* Component.useReactEffect(() =>
+                Effect.gen(function*() {
+                    yield* Effect.sync(() => lifecycle(`mount:${props.value}`))
+                    yield* Effect.addFinalizer(() => Effect.sync(() => lifecycle(`cleanup:${props.value}`)))
+                }),
+            [props.value])
+
+            return <div>{props.value}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value="first" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first")
+        await waitFor(() => expect(lifecycle).toHaveBeenCalledWith("mount:first"))
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value="second" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("second")
+        await waitFor(() => expect(lifecycle).toHaveBeenCalledWith("cleanup:first"))
+        await waitFor(() => expect(lifecycle).toHaveBeenCalledWith("mount:second"))
+
+        view.unmount()
+
+        await waitFor(() => expect(lifecycle).toHaveBeenCalledWith("cleanup:second"))
+        expect(lifecycle.mock.calls.map(([message]) => message)).toEqual([
+            "mount:first",
+            "cleanup:first",
+            "mount:second",
+            "cleanup:second",
+        ])
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+
+    it("keeps useCallbackSync stable until dependencies change", async () => {
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+        const seenCallbacks: Array<(value: number) => string> = []
+
+        const Probe = Component.makeUntraced("UseCallbackSyncProbe")(function*(props: { readonly prefix: string }) {
+            const callback = yield* Component.useCallbackSync(
+                (value: number) => Effect.succeed(`${props.prefix}:${value}`),
+                [props.prefix],
+            )
+
+            yield* Component.useOnMount(() => Effect.sync(() => {
+                seenCallbacks.push(callback)
+            }))
+
+            React.useEffect(() => {
+                seenCallbacks.push(callback)
+            }, [callback])
+
+            return <div>{callback(1)}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe prefix="a" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("a:1")
+        expect(seenCallbacks).toHaveLength(2)
+        expect(seenCallbacks[0]).toBe(seenCallbacks[1])
+        expect(seenCallbacks[0]?.(2)).toBe("a:2")
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe prefix="a" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("a:1")
+        expect(seenCallbacks).toHaveLength(2)
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe prefix="b" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("b:1")
+        await waitFor(() => expect(seenCallbacks).toHaveLength(3))
+        expect(seenCallbacks[2]).not.toBe(seenCallbacks[1])
+        expect(seenCallbacks[2]?.(2)).toBe("b:2")
+
+        view.unmount()
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+
+    it("delays cleanup according to finalizerExecutionDebounce", async () => {
+        const cleanup = vi.fn()
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+        const Probe = Component.makeUntraced("DebouncedCleanupProbe")(function*(props: { readonly value: string }) {
+            const result = yield* Component.useOnChange(
+                () => Effect.gen(function*() {
+                    yield* Effect.addFinalizer(() => Effect.sync(() => cleanup(props.value)))
+                    return props.value
+                }),
+                [props.value],
+                { finalizerExecutionDebounce: "20 millis" },
+            )
+
+            return <div>{result}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value="first" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first")
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe value="second" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("second")
+        expect(cleanup).not.toHaveBeenCalled()
+
+        await new Promise(resolve => setTimeout(resolve, 5))
+        expect(cleanup).not.toHaveBeenCalled()
+
+        await waitFor(() => expect(cleanup).toHaveBeenCalledWith("first"), { timeout: 100 })
+
+        view.unmount()
+        await waitFor(() => expect(cleanup).toHaveBeenCalledWith("second"), { timeout: 100 })
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+
+    it("does not remount a component when only nonReactiveTags change", async () => {
+        const mounts = vi.fn()
+        const unmounts = vi.fn()
+        const runtime = ReactRuntime.make(Layer.empty)
+        const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+        const SubComponent = Component.makeUntraced("NonReactiveSubComponent")(function*() {
+            const service = yield* ValueService
+
+            yield* Component.useOnMount(() => Effect.gen(function*() {
+                yield* Effect.sync(() => mounts())
+                yield* Effect.addFinalizer(() => Effect.sync(() => unmounts()))
+            }))
+
+            return <div>{service.value}</div>
+        }).pipe(
+            Component.withOptions({ nonReactiveTags: [ValueService] })
+        )
+
+        const Parent = Component.makeUntraced("NonReactiveParent")(function*(props: { readonly value: string }) {
+            const serviceLayer = React.useMemo(
+                () => Layer.succeed(ValueService, { value: props.value }),
+                [props.value],
+            )
+            const context = yield* Component.useContextFromLayer(serviceLayer, {
+                finalizerExecutionDebounce: 0,
+            })
+            const Child = yield* Effect.provide(SubComponent.use, context)
+
+            return <Child />
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Parent value="first" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first")
+        expect(mounts).toHaveBeenCalledTimes(1)
+        expect(unmounts).not.toHaveBeenCalled()
+
+        view.rerender(
+            <runtime.context.Provider value={effectRuntime}>
+                <Parent value="second" />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("second")
+        expect(mounts).toHaveBeenCalledTimes(1)
+        expect(unmounts).not.toHaveBeenCalled()
+
+        view.unmount()
+        await waitFor(() => expect(unmounts).toHaveBeenCalledTimes(1))
+        await Effect.runPromise(runtime.runtime.disposeEffect)
+    })
+})

packages/effect-fc/test/Lens.test.tsx

@@ -0,0 +1,165 @@
+import { fireEvent, render, screen, waitFor } from "@testing-library/react"
+import { Effect, Layer, SubscriptionRef } from "effect"
+import * as React from "react"
+import { describe, expect, it } from "vitest"
+import * as Component from "../src/Component.js"
+import * as Lens from "../src/Lens.js"
+import * as ReactRuntime from "../src/ReactRuntime.js"
+
+
+const makeRuntime = async () => {
+    const runtime = ReactRuntime.make(Layer.empty)
+    const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+    return {
+        runtime,
+        effectRuntime,
+        dispose: () => Effect.runPromise(runtime.runtime.disposeEffect),
+    }
+}
+
+describe("Lens", () => {
+    it("useState stays in sync with lens updates in both directions", async () => {
+        const { runtime, effectRuntime, dispose } = await makeRuntime()
+        const ref = await Effect.runPromise(SubscriptionRef.make(0))
+        const lens = Lens.fromSubscriptionRef(ref)
+
+        const Probe = Component.makeUntraced("LensUseStateProbe")(function*() {
+            const [value, setValue] = yield* Lens.useState(lens)
+
+            return (
+                <>
+                    <div>{value}</div>
+                    <button onClick={() => setValue(previous => previous + 1)}>increment</button>
+                </>
+            )
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("0")
+
+        await Effect.runPromise(Lens.set(lens, 5))
+        await screen.findByText("5")
+
+        fireEvent.click(screen.getByRole("button", { name: "increment" }))
+        await screen.findByText("6")
+        expect(await Effect.runPromise(Lens.get(lens))).toBe(6)
+
+        view.unmount()
+        await dispose()
+    })
+
+    it("useState respects the provided equivalence when subscribing to lens changes", async () => {
+        const { runtime, effectRuntime, dispose } = await makeRuntime()
+        const ref = await Effect.runPromise(SubscriptionRef.make({ id: 1, label: "first" }))
+        const lens = Lens.fromSubscriptionRef(ref)
+
+        const Probe = Component.makeUntraced("LensUseStateEquivalenceProbe")(function*() {
+            const [value] = yield* Lens.useState(lens, {
+                equivalence: (self, that) => self.id === that.id,
+            })
+
+            return <div>{value.label}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first")
+
+        await Effect.runPromise(Lens.set(lens, { id: 1, label: "ignored" }))
+        await waitFor(() => expect(screen.getByText("first")).toBeTruthy())
+        expect(screen.queryByText("ignored")).toBeNull()
+
+        await Effect.runPromise(Lens.set(lens, { id: 2, label: "updated" }))
+        await screen.findByText("updated")
+
+        view.unmount()
+        await dispose()
+    })
+
+    it("useFromReactState writes React state changes into the returned lens", async () => {
+        const { runtime, effectRuntime, dispose } = await makeRuntime()
+        let lens: Lens.Lens<string, never, never, never, never> | undefined
+
+        const Probe = Component.makeUntraced("LensUseFromReactStateProbe")(function*() {
+            const [value, setValue] = React.useState("hello")
+            const reactLens = yield* Lens.useFromReactState([value, setValue])
+
+            yield* Component.useOnMount(() => Effect.sync(() => {
+                lens = reactLens
+            }))
+
+            return <button onClick={() => setValue(previous => `${previous}!`)}>{value}</button>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("hello")
+        await waitFor(() => expect(lens).toBeDefined())
+
+        fireEvent.click(screen.getByRole("button", { name: "hello" }))
+        await screen.findByText("hello!")
+        await waitFor(async () => expect(await Effect.runPromise(Lens.get(lens!))).toBe("hello!"))
+
+        view.unmount()
+        await dispose()
+    })
+
+    it("useFromReactState respects equivalence when lens updates flow back into React state", async () => {
+        const { runtime, effectRuntime, dispose } = await makeRuntime()
+        let lens: Lens.Lens<{ readonly id: number; readonly label: string }, never, never, never, never> | undefined
+
+        const Probe = Component.makeUntraced("LensUseFromReactStateEquivalenceProbe")(function*() {
+            const [value, setValue] = React.useState({ id: 1, label: "first" })
+            const reactLens = yield* Lens.useFromReactState([value, setValue], {
+                equivalence: (self, that) => self.id === that.id,
+            })
+
+            yield* Component.useOnMount(() => Effect.sync(() => {
+                lens = reactLens
+            }))
+
+            return <div>{value.label}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first")
+        await waitFor(() => expect(lens).toBeDefined())
+
+        await Effect.runPromise(Lens.set(lens!, { id: 1, label: "ignored" }))
+        await waitFor(() => expect(screen.getByText("first")).toBeTruthy())
+        expect(screen.queryByText("ignored")).toBeNull()
+
+        await Effect.runPromise(Lens.set(lens!, { id: 2, label: "updated" }))
+        await screen.findByText("updated")
+
+        view.unmount()
+        await dispose()
+    })
+})

packages/effect-fc/test/Query.test.ts

@@ -0,0 +1,169 @@
+import { Effect, Option, type Scope, Stream } from "effect"
+import { describe, expect, it } from "vitest"
+import * as Query from "../src/Query.js"
+import * as QueryClient from "../src/QueryClient.js"
+import * as Result from "../src/Result.js"
+
+
+const runQueryTest = <A, E>(effect: Effect.Effect<A, E, QueryClient.QueryClient | Scope.Scope>) =>
+    Effect.runPromise(Effect.scoped(effect.pipe(
+        Effect.provide(QueryClient.QueryClient.Default),
+    )))
+
+const expectSuccessValue = <A, E, P>(
+    result: Result.Result<A, E, P>,
+): A => {
+    expect(Result.isSuccess(result)).toBe(true)
+
+    if (!Result.isSuccess(result))
+        throw new Error(`Expected Success result, received ${result._tag}`)
+
+    return result.value
+}
+
+const expectSomeValue = <A>(option: Option.Option<A>): A => {
+    expect(Option.isSome(option)).toBe(true)
+
+    if (!Option.isSome(option))
+        throw new Error("Expected Some option, received None")
+
+    return option.value
+}
+
+describe("Query", () => {
+    it("fetch caches successful results until they are invalidated or stale", async () => {
+        let calls = 0
+        const key = Stream.empty as Stream.Stream<readonly [number]>
+
+        const result = await runQueryTest(Effect.gen(function*() {
+            const query = yield* Query.make({
+                key,
+                f: ([id]: readonly [number]) => Effect.sync(() => {
+                    calls += 1
+                    return `value:${id}:${calls}`
+                }),
+                staleTime: "1 minute",
+            })
+
+            const first = yield* query.fetch([1])
+            const second = yield* query.fetch([1])
+
+            return [first, second] as const
+        }))
+
+        expect(calls).toBe(1)
+        expect(result[0]._tag).toBe("Success")
+        expect(result[1]._tag).toBe("Success")
+        expect(expectSuccessValue(result[0])).toBe("value:1:1")
+        expect(expectSuccessValue(result[1])).toBe("value:1:1")
+    })
+
+    it("refresh reruns the latest query key", async () => {
+        let calls = 0
+        const key = Stream.empty as Stream.Stream<readonly [number]>
+
+        const result = await runQueryTest(Effect.gen(function*() {
+            const query = yield* Query.make({
+                key,
+                f: ([id]: readonly [number]) => Effect.sync(() => {
+                    calls += 1
+                    return `value:${id}:${calls}`
+                }),
+                staleTime: "0 millis",
+            })
+
+            const first = yield* query.fetch([1])
+            yield* Effect.sleep("1 millis")
+            const refreshed = yield* query.refresh
+
+            return [first, refreshed] as const
+        }))
+
+        expect(calls).toBe(2)
+        expect(expectSuccessValue(result[0])).toBe("value:1:1")
+        expect(expectSuccessValue(result[1])).toBe("value:1:2")
+    })
+
+    it("invalidateCacheEntry forces the next fetch for that key to rerun", async () => {
+        let calls = 0
+        const key = Stream.empty as Stream.Stream<readonly [number]>
+
+        const result = await runQueryTest(Effect.gen(function*() {
+            const query = yield* Query.make({
+                key,
+                f: ([id]: readonly [number]) => Effect.sync(() => {
+                    calls += 1
+                    return `value:${id}:${calls}`
+                }),
+                staleTime: "1 minute",
+            })
+
+            const first = yield* query.fetch([1])
+            yield* query.invalidateCacheEntry([1])
+            const second = yield* query.fetch([1])
+
+            return [first, second] as const
+        }))
+
+        expect(calls).toBe(2)
+        expect(expectSuccessValue(result[0])).toBe("value:1:1")
+        expect(expectSuccessValue(result[1])).toBe("value:1:2")
+    })
+
+    it("invalidateCache clears cached entries for the query function", async () => {
+        let calls = 0
+        const key = Stream.empty as Stream.Stream<readonly [number]>
+
+        const result = await runQueryTest(Effect.gen(function*() {
+            const query = yield* Query.make({
+                key,
+                f: ([id]: readonly [number]) => Effect.sync(() => {
+                    calls += 1
+                    return `value:${id}:${calls}`
+                }),
+                staleTime: "1 minute",
+            })
+
+            const first = yield* query.fetch([1])
+            yield* query.invalidateCache
+            const second = yield* query.fetch([1])
+
+            return [first, second] as const
+        }))
+
+        expect(calls).toBe(2)
+        expect(expectSuccessValue(result[0])).toBe("value:1:1")
+        expect(expectSuccessValue(result[1])).toBe("value:1:2")
+    })
+
+    it("service starts the key stream automatically and updates latest state", async () => {
+        let calls = 0
+        const key = Stream.make([1] as const) as Stream.Stream<readonly [number]>
+
+        const effect = Effect.gen(function*() {
+            const query = yield* Query.service({
+                key,
+                f: ([id]: readonly [number]) => Effect.sync(() => {
+                    calls += 1
+                    return `value:${id}:${calls}`
+                }),
+                staleTime: "1 minute",
+            })
+
+            yield* Effect.sleep("10 millis")
+
+            return {
+                final: yield* query.result.get,
+                latestKey: yield* query.latestKey.get,
+                latestFinalResult: yield* query.latestFinalResult.get,
+            }
+        })
+
+        const result = await runQueryTest(effect)
+
+        expect(calls).toBe(1)
+        expect(expectSuccessValue(result.final)).toBe("value:1:1")
+        expect(expectSomeValue(result.latestKey)).toEqual([1])
+        expect(expectSuccessValue(expectSomeValue(result.latestFinalResult))).toBe("value:1:1")
+    })
+})

packages/effect-fc/test/Subscribable.test.tsx

@@ -0,0 +1,129 @@
+import { render, screen, waitFor } from "@testing-library/react"
+import { Effect, Fiber, Layer, Stream, SubscriptionRef } from "effect"
+import { Lens } from "effect-lens"
+import { describe, expect, it } from "vitest"
+import * as Component from "../src/Component.js"
+import * as ReactRuntime from "../src/ReactRuntime.js"
+import * as Subscribable from "../src/Subscribable.js"
+
+
+const makeRuntime = async () => {
+    const runtime = ReactRuntime.make(Layer.empty)
+    const effectRuntime = await Effect.runPromise(runtime.runtime.runtimeEffect)
+
+    return {
+        runtime,
+        effectRuntime,
+        dispose: () => Effect.runPromise(runtime.runtime.disposeEffect),
+    }
+}
+
+describe("Subscribable", () => {
+    it("zipLatestAll reads current values from all inputs", async () => {
+        const leftRef = await Effect.runPromise(SubscriptionRef.make(1))
+        const rightRef = await Effect.runPromise(SubscriptionRef.make("a"))
+        const left = Lens.fromSubscriptionRef(leftRef)
+        const right = Lens.fromSubscriptionRef(rightRef)
+
+        const zipped = Subscribable.zipLatestAll(left, right)
+
+        expect(await Effect.runPromise(zipped.get)).toEqual([1, "a"])
+    })
+
+    it("zipLatestAll emits updates when any input changes", async () => {
+        const leftRef = await Effect.runPromise(SubscriptionRef.make(1))
+        const rightRef = await Effect.runPromise(SubscriptionRef.make("a"))
+        const left = Lens.fromSubscriptionRef(leftRef)
+        const right = Lens.fromSubscriptionRef(rightRef)
+
+        const zipped = Subscribable.zipLatestAll(left, right)
+        const values: Array<readonly [number, string]> = []
+
+        const collector = Effect.runFork(Effect.scoped(zipped.changes.pipe(
+            Stream.runForEach(value => Effect.sync(() => {
+                values.push(value as readonly [number, string])
+            })),
+        )))
+
+        await Effect.runPromise(Lens.set(left, 2))
+        await waitFor(() => expect(values).toContainEqual([2, "a"]))
+
+        await Effect.runPromise(Lens.set(right, "b"))
+        await waitFor(() => expect(values).toContainEqual([2, "b"]))
+
+        Fiber.interruptFork(collector)
+    })
+
+    it("useAll returns the latest values and rerenders when any input changes", async () => {
+        const { runtime, effectRuntime, dispose } = await makeRuntime()
+        const countRef = await Effect.runPromise(SubscriptionRef.make(1))
+        const labelRef = await Effect.runPromise(SubscriptionRef.make("a"))
+        const count = Lens.fromSubscriptionRef(countRef)
+        const label = Lens.fromSubscriptionRef(labelRef)
+
+        const Probe = Component.makeUntraced("SubscribableUseAllProbe")(function*() {
+            const [currentCount, currentLabel] = yield* Subscribable.useAll([count, label])
+
+            return <div>{`${currentCount}:${currentLabel}`}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("1:a")
+
+        await Effect.runPromise(Lens.set(count, 2))
+        await screen.findByText("2:a")
+
+        await Effect.runPromise(Lens.set(label, "b"))
+        await screen.findByText("2:b")
+
+        view.unmount()
+        await dispose()
+    })
+
+    it("useAll respects the provided equivalence when processing updates", async () => {
+        const { runtime, effectRuntime, dispose } = await makeRuntime()
+        const itemRef = await Effect.runPromise(SubscriptionRef.make({ id: 1, label: "first" }))
+        const flagRef = await Effect.runPromise(SubscriptionRef.make(true))
+        const item = Lens.fromSubscriptionRef(itemRef)
+        const flag = Lens.fromSubscriptionRef(flagRef)
+
+        const Probe = Component.makeUntraced("SubscribableUseAllEquivalenceProbe")(function*() {
+            const [currentItem, currentFlag] = yield* Subscribable.useAll([item, flag], {
+                equivalence: ([selfItem, selfFlag], [thatItem, thatFlag]) =>
+                    selfItem.id === thatItem.id && selfFlag === thatFlag,
+            })
+
+            return <div>{`${currentItem.label}:${currentFlag ? "on" : "off"}`}</div>
+        }).pipe(
+            Component.withRuntime(runtime.context)
+        )
+
+        const view = render(
+            <runtime.context.Provider value={effectRuntime}>
+                <Probe />
+            </runtime.context.Provider>
+        )
+
+        await screen.findByText("first:on")
+
+        await Effect.runPromise(Lens.set(item, { id: 1, label: "ignored" }))
+        await waitFor(() => expect(screen.getByText("first:on")).toBeTruthy())
+        expect(screen.queryByText("ignored:on")).toBeNull()
+
+        await Effect.runPromise(Lens.set(flag, false))
+        await screen.findByText("ignored:off")
+
+        await Effect.runPromise(Lens.set(item, { id: 2, label: "updated" }))
+        await screen.findByText("updated:off")
+
+        view.unmount()
+        await dispose()
+    })
+})

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/effect-fc/vitest.config.ts

@@ -0,0 +1,9 @@
+import { defineConfig } from "vitest/config"
+
+
+export default defineConfig({
+    test: {
+        environment: "jsdom",
+        include: ["test/**/*.test.ts?(x)"],
+    },
+})

packages/example/package.json

@@ -13,32 +13,30 @@
     "clean:modules": "rm -rf node_modules"
   },
   "devDependencies": {
-    "@tanstack/react-router": "^1.132.31",
+    "@tanstack/react-router": "^1.170.10",
-    "@tanstack/react-router-devtools": "^1.132.31",
+    "@tanstack/react-router-devtools": "^1.167.0",
-    "@tanstack/router-plugin": "^1.132.31",
+    "@tanstack/router-plugin": "^1.168.13",
-    "@types/react": "^19.2.0",
+    "@types/react": "^19.2.15",
-    "@types/react-dom": "^19.2.0",
+    "@types/react-dom": "^19.2.3",
-    "@vitejs/plugin-react": "^5.0.4",
+    "@vitejs/plugin-react": "^6.0.2",
-    "globals": "^16.4.0",
+    "globals": "^17.6.0",
-    "react": "^19.2.0",
+    "react": "^19.2.6",
-    "react-dom": "^19.2.0",
+    "react-dom": "^19.2.6",
-    "type-fest": "^5.0.1",
+    "type-fest": "^5.7.0",
-    "vite": "^7.1.8"
+    "vite": "^8.0.16"
   },
   "dependencies": {
-    "@effect/platform": "^0.92.1",
+    "@effect/platform": "^0.96.1",
-    "@effect/platform-browser": "^0.72.0",
+    "@effect/platform-browser": "^0.76.0",
-    "@radix-ui/themes": "^3.2.1",
+    "@radix-ui/themes": "^3.3.0",
-    "@typed/async-data": "^0.13.1",
     "@typed/id": "^0.17.2",
-    "@typed/lazy-ref": "^0.3.3",
+    "effect": "^3.21.2",
-    "effect": "^3.18.1",
     "effect-fc": "workspace:*",
-    "react-icons": "^5.5.0"
+    "react-icons": "^5.6.0"
   },
   "overrides": {
-    "@types/react": "^19.2.0",
+    "@types/react": "^19.2.15",
-    "effect": "^3.18.1",
+    "effect": "^3.21.2",
-    "react": "^19.2.0"
+    "react": "^19.2.6"
   }
 }

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

@@ -1,75 +0,0 @@
-import { Callout, Flex, Spinner, Switch, TextField } from "@radix-ui/themes"
-import { Array, Option, Struct } from "effect"
-import { Component, Form, Subscribable } from "effect-fc"
-
-
-interface Props
-extends TextField.RootProps, Form.useInput.Options {
-    readonly optional?: false
-    readonly field: Form.FormField<any, string>
-}
-
-interface OptionalProps
-extends Omit<TextField.RootProps, "optional" | "defaultValue">, Form.useOptionalInput.Options<string> {
-    readonly optional: true
-    readonly field: Form.FormField<any, Option.Option<string>>
-}
-
-export type TextFieldFormInputProps = Props | OptionalProps
-
-
-export class TextFieldFormInput extends Component.makeUntraced("TextFieldFormInput")(function*(props: TextFieldFormInputProps) {
-    const input: (
-        | { readonly optional: true } & Form.useOptionalInput.Result<string>
-        | { readonly optional: false } & Form.useInput.Result<string>
-    ) = props.optional
-        // biome-ignore lint/correctness/useHookAtTopLevel: "optional" reactivity not supported
-        ? { optional: true, ...yield* Form.useOptionalInput(props.field, props) }
-        // biome-ignore lint/correctness/useHookAtTopLevel: "optional" reactivity not supported
-        : { optional: false, ...yield* Form.useInput(props.field, props) }
-
-    const [issues, isValidating, isSubmitting] = yield* Subscribable.useSubscribables(
-        props.field.issuesSubscribable,
-        props.field.isValidatingSubscribable,
-        props.field.isSubmittingSubscribable,
-    )
-
-    return (
-        <Flex direction="column" gap="1">
-            <TextField.Root
-                value={input.value}
-                onChange={e => input.setValue(e.target.value)}
-                disabled={(input.optional && !input.enabled) || isSubmitting}
-                {...Struct.omit(props, "optional", "defaultValue")}
-            >
-                {input.optional &&
-                    <TextField.Slot side="left">
-                        <Switch
-                            size="1"
-                            checked={input.enabled}
-                            onCheckedChange={input.setEnabled}
-                        />
-                    </TextField.Slot>
-                }
-
-                {isValidating &&
-                    <TextField.Slot side="right">
-                        <Spinner />
-                    </TextField.Slot>
-                }
-
-                {props.children}
-            </TextField.Root>
-
-            {Option.match(Array.head(issues), {
-                onSome: issue => (
-                    <Callout.Root>
-                        <Callout.Text>{issue.message}</Callout.Text>
-                    </Callout.Root>
-                ),
-
-                onNone: () => <></>,
-            })}
-        </Flex>
-    )
-}) {}

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

@@ -0,0 +1,56 @@
+import { Callout, Flex, Spinner, TextField } from "@radix-ui/themes"
+import { Array, Option, Struct } from "effect"
+import { Component, Form, Subscribable } from "effect-fc"
+import type * as React from "react"
+
+
+export declare namespace TextFieldFormInputView {
+    export interface Props<out P extends readonly PropertyKey[], A, ER, EW>
+    extends Omit<TextField.RootProps, "form">, Form.useInput.Options {
+        readonly form: Form.Form<P, A, string, ER, EW>
+    }
+
+    export type Signature = <P extends readonly PropertyKey[], A, ER, EW>(props: Props<P, A, ER, EW>) => React.ReactNode
+}
+
+export const TextFieldFormInputView = Component.make("TextFieldFormInputView")(function*(
+    props: TextFieldFormInputView.Props<readonly PropertyKey[], any, any, any>
+) {
+    const input = yield* Form.useInput(props.form, props)
+    const [issues, isValidating, isCommitting] = yield* Subscribable.useAll([
+        props.form.issues,
+        props.form.isValidating,
+        props.form.isCommitting,
+    ])
+
+    return (
+        <Flex direction="column" gap="1">
+            <TextField.Root
+                value={input.value}
+                onChange={e => input.setValue(e.target.value)}
+                disabled={isCommitting}
+                {...Struct.omit(props, "form")}
+            >
+                {isValidating &&
+                    <TextField.Slot side="right">
+                        <Spinner />
+                    </TextField.Slot>
+                }
+
+                {props.children}
+            </TextField.Root>
+
+            {Option.match(Array.head(issues), {
+                onSome: issue => (
+                    <Callout.Root>
+                        <Callout.Text>{issue.message}</Callout.Text>
+                    </Callout.Root>
+                ),
+
+                onNone: () => <></>,
+            })}
+        </Flex>
+    )
+}).pipe(
+    Component.withSignature<TextFieldFormInputView.Signature>()
+)

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

@@ -0,0 +1,64 @@
+import { Callout, Flex, Spinner, Switch, TextField } from "@radix-ui/themes"
+import { Array, Option, Struct } from "effect"
+import { Component, Form, Subscribable } from "effect-fc"
+import type * as React from "react"
+
+
+export declare namespace TextFieldOptionalFormInputView {
+    export interface Props<out P extends readonly PropertyKey[], A, ER, EW>
+    extends Omit<TextField.RootProps, "form" | "defaultValue">, Form.useOptionalInput.Options<string> {
+        readonly form: Form.Form<P, A, Option.Option<string>, ER, EW>
+    }
+
+    export type Signature = <P extends readonly PropertyKey[], A, ER, EW>(props: Props<P, A, ER, EW>) => React.ReactNode
+}
+
+export const TextFieldOptionalFormInputView = Component.make("TextFieldOptionalFormInputView")(function*(
+    props: TextFieldOptionalFormInputView.Props<readonly PropertyKey[], any, any, any>
+) {
+    const input = yield* Form.useOptionalInput(props.form, props)
+    const [issues, isValidating, isCommitting] = yield* Subscribable.useAll([
+        props.form.issues,
+        props.form.isValidating,
+        props.form.isCommitting,
+    ])
+
+    return (
+        <Flex direction="column" gap="1">
+            <TextField.Root
+                value={input.value}
+                onChange={e => input.setValue(e.target.value)}
+                disabled={!input.enabled || isCommitting}
+                {...Struct.omit(props, "form", "defaultValue")}
+            >
+                <TextField.Slot side="left">
+                    <Switch
+                        size="1"
+                        checked={input.enabled}
+                        onCheckedChange={input.setEnabled}
+                    />
+                </TextField.Slot>
+
+                {isValidating &&
+                    <TextField.Slot side="right">
+                        <Spinner />
+                    </TextField.Slot>
+                }
+
+                {props.children}
+            </TextField.Root>
+
+            {Option.match(Array.head(issues), {
+                onSome: issue => (
+                    <Callout.Root>
+                        <Callout.Text>{issue.message}</Callout.Text>
+                    </Callout.Root>
+                ),
+
+                onNone: () => <></>,
+            })}
+        </Flex>
+    )
+}).pipe(
+    Component.withSignature<TextFieldOptionalFormInputView.Signature>()
+)

packages/example/src/routeTree.gen.ts

@@ -9,13 +9,25 @@
 // Additionally, you should also exclude this file from your linter and/or formatter to prevent it from being checked or modified.
 
 import { Route as rootRouteImport } from './routes/__root'
+import { Route as ResultRouteImport } from './routes/result'
+import { Route as QueryRouteImport } from './routes/query'
 import { Route as FormRouteImport } from './routes/form'
 import { Route as BlankRouteImport } from './routes/blank'
+import { Route as AsyncRouteImport } from './routes/async'
 import { Route as IndexRouteImport } from './routes/index'
 import { Route as DevMemoRouteImport } from './routes/dev/memo'
 import { Route as DevContextRouteImport } from './routes/dev/context'
-import { Route as DevAsyncRenderingRouteImport } from './routes/dev/async-rendering'
 
+const ResultRoute = ResultRouteImport.update({
+  id: '/result',
+  path: '/result',
+  getParentRoute: () => rootRouteImport,
+} as any)
+const QueryRoute = QueryRouteImport.update({
+  id: '/query',
+  path: '/query',
+  getParentRoute: () => rootRouteImport,
+} as any)
 const FormRoute = FormRouteImport.update({
   id: '/form',
   path: '/form',
@@ -26,6 +38,11 @@ const BlankRoute = BlankRouteImport.update({
   path: '/blank',
   getParentRoute: () => rootRouteImport,
 } as any)
+const AsyncRoute = AsyncRouteImport.update({
+  id: '/async',
+  path: '/async',
+  getParentRoute: () => rootRouteImport,
+} as any)
 const IndexRoute = IndexRouteImport.update({
   id: '/',
   path: '/',
@@ -41,34 +58,35 @@ const DevContextRoute = DevContextRouteImport.update({
   path: '/dev/context',
   getParentRoute: () => rootRouteImport,
 } as any)
-const DevAsyncRenderingRoute = DevAsyncRenderingRouteImport.update({
-  id: '/dev/async-rendering',
-  path: '/dev/async-rendering',
-  getParentRoute: () => rootRouteImport,
-} as any)
 
 export interface FileRoutesByFullPath {
   '/': typeof IndexRoute
+  '/async': typeof AsyncRoute
   '/blank': typeof BlankRoute
   '/form': typeof FormRoute
-  '/dev/async-rendering': typeof DevAsyncRenderingRoute
+  '/query': typeof QueryRoute
+  '/result': typeof ResultRoute
   '/dev/context': typeof DevContextRoute
   '/dev/memo': typeof DevMemoRoute
 }
 export interface FileRoutesByTo {
   '/': typeof IndexRoute
+  '/async': typeof AsyncRoute
   '/blank': typeof BlankRoute
   '/form': typeof FormRoute
-  '/dev/async-rendering': typeof DevAsyncRenderingRoute
+  '/query': typeof QueryRoute
+  '/result': typeof ResultRoute
   '/dev/context': typeof DevContextRoute
   '/dev/memo': typeof DevMemoRoute
 }
 export interface FileRoutesById {
   __root__: typeof rootRouteImport
   '/': typeof IndexRoute
+  '/async': typeof AsyncRoute
   '/blank': typeof BlankRoute
   '/form': typeof FormRoute
-  '/dev/async-rendering': typeof DevAsyncRenderingRoute
+  '/query': typeof QueryRoute
+  '/result': typeof ResultRoute
   '/dev/context': typeof DevContextRoute
   '/dev/memo': typeof DevMemoRoute
 }
@@ -76,40 +94,62 @@ export interface FileRouteTypes {
   fileRoutesByFullPath: FileRoutesByFullPath
   fullPaths:
     | '/'
+    | '/async'
     | '/blank'
     | '/form'
-    | '/dev/async-rendering'
+    | '/query'
+    | '/result'
     | '/dev/context'
     | '/dev/memo'
   fileRoutesByTo: FileRoutesByTo
   to:
     | '/'
+    | '/async'
     | '/blank'
     | '/form'
-    | '/dev/async-rendering'
+    | '/query'
+    | '/result'
     | '/dev/context'
     | '/dev/memo'
   id:
     | '__root__'
     | '/'
+    | '/async'
     | '/blank'
     | '/form'
-    | '/dev/async-rendering'
+    | '/query'
+    | '/result'
     | '/dev/context'
     | '/dev/memo'
   fileRoutesById: FileRoutesById
 }
 export interface RootRouteChildren {
   IndexRoute: typeof IndexRoute
+  AsyncRoute: typeof AsyncRoute
   BlankRoute: typeof BlankRoute
   FormRoute: typeof FormRoute
-  DevAsyncRenderingRoute: typeof DevAsyncRenderingRoute
+  QueryRoute: typeof QueryRoute
+  ResultRoute: typeof ResultRoute
   DevContextRoute: typeof DevContextRoute
   DevMemoRoute: typeof DevMemoRoute
 }
 
 declare module '@tanstack/react-router' {
   interface FileRoutesByPath {
+    '/result': {
+      id: '/result'
+      path: '/result'
+      fullPath: '/result'
+      preLoaderRoute: typeof ResultRouteImport
+      parentRoute: typeof rootRouteImport
+    }
+    '/query': {
+      id: '/query'
+      path: '/query'
+      fullPath: '/query'
+      preLoaderRoute: typeof QueryRouteImport
+      parentRoute: typeof rootRouteImport
+    }
     '/form': {
       id: '/form'
       path: '/form'
@@ -124,6 +164,13 @@ declare module '@tanstack/react-router' {
       preLoaderRoute: typeof BlankRouteImport
       parentRoute: typeof rootRouteImport
     }
+    '/async': {
+      id: '/async'
+      path: '/async'
+      fullPath: '/async'
+      preLoaderRoute: typeof AsyncRouteImport
+      parentRoute: typeof rootRouteImport
+    }
     '/': {
       id: '/'
       path: '/'
@@ -145,21 +192,16 @@ declare module '@tanstack/react-router' {
       preLoaderRoute: typeof DevContextRouteImport
       parentRoute: typeof rootRouteImport
     }
-    '/dev/async-rendering': {
-      id: '/dev/async-rendering'
-      path: '/dev/async-rendering'
-      fullPath: '/dev/async-rendering'
-      preLoaderRoute: typeof DevAsyncRenderingRouteImport
-      parentRoute: typeof rootRouteImport
-    }
   }
 }
 
 const rootRouteChildren: RootRouteChildren = {
   IndexRoute: IndexRoute,
+  AsyncRoute: AsyncRoute,
   BlankRoute: BlankRoute,
   FormRoute: FormRoute,
-  DevAsyncRenderingRoute: DevAsyncRenderingRoute,
+  QueryRoute: QueryRoute,
+  ResultRoute: ResultRoute,
   DevContextRoute: DevContextRoute,
   DevMemoRoute: DevMemoRoute,
 }

packages/example/src/routes/async.tsx

@@ -0,0 +1,71 @@
+import { HttpClient } from "@effect/platform"
+import { Container, Flex, Heading, Slider, Text, TextField } from "@radix-ui/themes"
+import { createFileRoute } from "@tanstack/react-router"
+import { Array, Effect, flow, Option, Schema } from "effect"
+import { Async, Component, Memoized } from "effect-fc"
+import * as React from "react"
+import { runtime } from "@/runtime"
+
+
+const Post = Schema.Struct({
+    userId: Schema.Int,
+    id: Schema.Int,
+    title: Schema.String,
+    body: Schema.String,
+})
+
+interface AsyncFetchPostViewProps {
+    readonly id: number
+}
+
+class AsyncFetchPostView extends Component.make("AsyncFetchPostView")(function*(props: AsyncFetchPostViewProps) {
+    const post = yield* Component.useOnChange(() => HttpClient.HttpClient.pipe(
+        Effect.tap(Effect.sleep("500 millis")),
+        Effect.andThen(client => client.get(`https://jsonplaceholder.typicode.com/posts/${ props.id }`)),
+        Effect.andThen(response => response.json),
+        Effect.andThen(Schema.decodeUnknown(Post)),
+    ), [props.id])
+
+    return (
+        <div>
+            <Heading>{post.title}</Heading>
+            <Text>{post.body}</Text>
+        </div>
+    )
+}).pipe(
+    Async.async,
+    Async.withOptions({ defaultFallback: <Text>Default fallback</Text> }),
+    Memoized.memoized,
+) {}
+
+
+const AsyncRouteComponent = Component.make("AsyncRouteView")(function*() {
+    const [text, setText] = React.useState("Typing here should not trigger a refetch of the post")
+    const [id, setId] = React.useState(1)
+
+    const AsyncFetchPost = yield* AsyncFetchPostView.use
+
+    return (
+        <Container>
+            <Flex direction="column" align="stretch" gap="2">
+                <TextField.Root
+                    value={text}
+                    onChange={e => setText(e.currentTarget.value)}
+                />
+
+                <Slider
+                    value={[id]}
+                    onValueChange={flow(Array.head, Option.getOrThrow, setId)}
+                />
+
+                <AsyncFetchPost id={id} fallback={<Text>Loading post...</Text>} />
+            </Flex>
+        </Container>
+    )
+}).pipe(
+    Component.withRuntime(runtime.context)
+)
+
+export const Route = createFileRoute("/async")({
+    component: AsyncRouteComponent,
+})

packages/example/src/routes/dev/async-rendering.tsx

@@ -1,78 +0,0 @@
-import { Flex, Text, TextField } from "@radix-ui/themes"
-import { createFileRoute } from "@tanstack/react-router"
-import { GetRandomValues, makeUuid4 } from "@typed/id"
-import { Effect } from "effect"
-import { Async, Component, Memoized } from "effect-fc"
-import * as React from "react"
-import { runtime } from "@/runtime"
-
-
-// Generator version
-const RouteComponent = Component.makeUntraced(function* AsyncRendering() {
-    const MemoizedAsyncComponentFC = yield* MemoizedAsyncComponent
-    const AsyncComponentFC = yield* AsyncComponent
-    const [input, setInput] = React.useState("")
-
-    return (
-        <Flex direction="column" align="stretch" gap="2">
-            <TextField.Root
-                value={input}
-                onChange={e => setInput(e.target.value)}
-            />
-
-            <MemoizedAsyncComponentFC fallback={React.useMemo(() => <p>Loading memoized...</p>, [])} />
-            <AsyncComponentFC />
-        </Flex>
-    )
-}).pipe(
-    Component.withRuntime(runtime.context)
-)
-
-// Pipeline version
-// const RouteComponent = Component.make("RouteComponent")(() => Effect.Do,
-//     Effect.bind("VMemoizedAsyncComponent", () => Component.useFC(MemoizedAsyncComponent)),
-//     Effect.bind("VAsyncComponent", () => Component.useFC(AsyncComponent)),
-//     Effect.let("input", () => React.useState("")),
-
-//     Effect.map(({ input: [input, setInput], VAsyncComponent, VMemoizedAsyncComponent }) =>
-//         <Flex direction="column" align="stretch" gap="2">
-//             <TextField.Root
-//                 value={input}
-//                 onChange={e => setInput(e.target.value)}
-//             />
-
-//             <VMemoizedAsyncComponent />
-//             <VAsyncComponent />
-//         </Flex>
-//     ),
-// ).pipe(
-//     Component.withRuntime(runtime.context)
-// )
-
-
-class AsyncComponent extends Component.makeUntraced("AsyncComponent")(function*() {
-    const SubComponentFC = yield* SubComponent
-
-    yield* Effect.sleep("500 millis") // Async operation
-    // Cannot use React hooks after the async operation
-
-    return (
-        <Flex direction="column" align="stretch">
-            <Text>Rendered!</Text>
-            <SubComponentFC />
-        </Flex>
-    )
-}).pipe(
-    Async.async,
-    Async.withOptions({ defaultFallback: <p>Loading...</p> }),
-) {}
-class MemoizedAsyncComponent extends Memoized.memoized(AsyncComponent) {}
-
-class SubComponent extends Component.makeUntraced("SubComponent")(function*() {
-    const [state] = React.useState(yield* Component.useOnMount(() => Effect.provide(makeUuid4, GetRandomValues.CryptoRandom)))
-    return <Text>{state}</Text>
-}) {}
-
-export const Route = createFileRoute("/dev/async-rendering")({
-    component: RouteComponent
-})

packages/example/src/routes/dev/context.tsx

@@ -23,7 +23,7 @@ const SubComponent = Component.makeUntraced("SubComponent")(function*() {
 const ContextView = Component.makeUntraced("ContextView")(function*() {
     const [serviceValue, setServiceValue] = React.useState("test")
     const SubServiceLayer = React.useMemo(() => SubService.Default(serviceValue), [serviceValue])
-    const SubComponentFC = yield* Effect.provide(SubComponent, yield* Component.useContext(SubServiceLayer))
+    const SubComponentFC = yield* Effect.provide(SubComponent.use, yield* Component.useContextFromLayer(SubServiceLayer))
 
     return (
         <Container>

packages/example/src/routes/dev/memo.tsx

@@ -17,8 +17,8 @@ const RouteComponent = Component.makeUntraced("RouteComponent")(function*() {
                 onChange={e => setValue(e.target.value)}
             />
 
-            {yield* Effect.map(SubComponent, FC => <FC />)}
+            {yield* Effect.map(SubComponent.use, FC => <FC />)}
-            {yield* Effect.map(MemoizedSubComponent, FC => <FC />)}
+            {yield* Effect.map(MemoizedSubComponent.use, FC => <FC />)}
         </Flex>
     )
 }).pipe(

packages/example/src/routes/form.tsx

@@ -1,8 +1,9 @@
-import { Button, Container, Flex } from "@radix-ui/themes"
+import { Button, Container, Flex, Text } from "@radix-ui/themes"
 import { createFileRoute } from "@tanstack/react-router"
-import { Console, Effect, Option, ParseResult, Schema } from "effect"
+import { Console, Effect, Match, Option, ParseResult, Schema } from "effect"
-import { Component, Form, Subscribable } from "effect-fc"
+import { Component, Form, SubmittableForm, Subscribable } from "effect-fc"
-import { TextFieldFormInput } from "@/lib/form/TextFieldFormInput"
+import { TextFieldFormInputView } from "@/lib/form/TextFieldFormInputView"
+import { TextFieldOptionalFormInputView } from "@/lib/form/TextFieldOptionalFormInputView"
 import { DateTimeUtcFromZonedInput } from "@/lib/schema"
 import { runtime } from "@/runtime"
 
@@ -23,8 +24,24 @@ const RegisterFormSchema = Schema.Struct({
     birth: Schema.OptionFromSelf(DateTimeUtcFromZonedInput),
 })
 
-class RegisterForm extends Effect.Service<RegisterForm>()("RegisterForm", {
+const RegisterFormSubmitSchema = Schema.Struct({
-    scoped: Form.service({
+    email: Schema.transformOrFail(
+        Schema.String,
+        Schema.String,
+        {
+            decode: (input, _options, ast) => input !== "admin@admin.com"
+                ? ParseResult.succeed(input)
+                : ParseResult.fail(new ParseResult.Type(ast, input, "This email is already in use.")),
+            encode: ParseResult.succeed,
+        },
+    ),
+    password: Schema.String,
+    birth: Schema.OptionFromSelf(Schema.DateTimeUtcFromSelf),
+})
+
+class RegisterFormService extends Effect.Service<RegisterFormService>()("RegisterFormService", {
+    scoped: Effect.gen(function*() {
+        const form = yield* SubmittableForm.service({
             schema: RegisterFormSchema.pipe(
                 Schema.compose(
                     Schema.transformOrFail(
@@ -39,20 +56,31 @@ class RegisterForm extends Effect.Service<RegisterForm>()("RegisterForm", {
             ),
 
             initialEncodedValue: { email: "", password: "", birth: Option.none() },
-        onSubmit: v => Effect.sleep("500 millis").pipe(
+            f: Effect.fnUntraced(function*([value]) {
-            Effect.andThen(Console.log(v)),
+                yield* Effect.sleep("500 millis")
-            Effect.andThen(Effect.sync(() => alert("Done!"))),
+                return yield* Schema.decode(RegisterFormSubmitSchema)(value)
-        ),
+            }),
-        debounce: "500 millis",
+        })
+
+        return {
+            form,
+            emailField: Form.focusObjectOn(form, "email"),
+            passwordField: Form.focusObjectOn(form, "password"),
+            birthField: Form.focusObjectOn(form, "birth"),
+        } as const
     })
 }) {}
 
-class RegisterFormView extends Component.makeUntraced("RegisterFormView")(function*() {
+class RegisterFormView extends Component.make("RegisterFormView")(function*() {
-    const form = yield* RegisterForm
+    const form = yield* RegisterFormService
-    const submit = yield* Form.useSubmit(form)
+    const [canCommit, submitResult] = yield* Subscribable.useAll([
-    const [canSubmit] = yield* Subscribable.useSubscribables(form.canSubmitSubscribable)
+        form.form.canCommit,
+        form.form.mutation.result,
+    ])
 
-    const TextFieldFormInputFC = yield* TextFieldFormInput
+    const runPromise = yield* Component.useRunPromise()
+    const TextFieldFormInput = yield* TextFieldFormInputView.use
+    const TextFieldOptionalFormInput = yield* TextFieldOptionalFormInputView.use
 
     yield* Component.useOnMount(() => Effect.gen(function*() {
         yield* Effect.addFinalizer(() => Console.log("RegisterFormView unmounted"))
@@ -64,38 +92,47 @@ class RegisterFormView extends Component.makeUntraced("RegisterFormView")(functi
         <Container width="300">
             <form onSubmit={e => {
                 e.preventDefault()
-                void submit()
+                void runPromise(form.form.submit)
             }}>
                 <Flex direction="column" gap="2">
-                    <TextFieldFormInputFC
+                    <TextFieldFormInput
-                        field={Form.useField(form, ["email"])}
+                        form={form.emailField}
+                        debounce="250 millis"
                     />
 
-                    <TextFieldFormInputFC
+                    <TextFieldFormInput
-                        field={Form.useField(form, ["password"])}
+                        form={form.passwordField}
+                        debounce="250 millis"
                     />
 
-                    <TextFieldFormInputFC
+                    <TextFieldOptionalFormInput
-                        optional
                         type="datetime-local"
-                        field={Form.useField(form, ["birth"])}
+                        form={form.birthField}
                         defaultValue=""
                     />
 
-                    <Button disabled={!canSubmit}>Submit</Button>
+                    <Button disabled={!canCommit}>Submit</Button>
                 </Flex>
             </form>
+
+            {Match.value(submitResult).pipe(
+                Match.tag("Initial", () => <></>),
+                Match.tag("Running", () => <Text>Submitting...</Text>),
+                Match.tag("Success", () => <Text>Submitted successfully!</Text>),
+                Match.tag("Failure", e => <Text>Error: {e.cause.toString()}</Text>),
+                Match.exhaustive,
+            )}
         </Container>
     )
 }) {}
 
-const RegisterPage = Component.makeUntraced("RegisterPage")(function*() {
+const RegisterPage = Component.make("RegisterPageView")(function*() {
-    const RegisterFormViewFC = yield* Effect.provide(
+    const RegisterForm = yield* Effect.provide(
-        RegisterFormView,
+        RegisterFormView.use,
-        yield* Component.useContext(RegisterForm.Default),
+        yield* Component.useContextFromLayer(RegisterFormService.Default),
     )
 
-    return <RegisterFormViewFC />
+    return <RegisterForm />
 }).pipe(
     Component.withRuntime(runtime.context)
 )

packages/example/src/routes/index.tsx

@@ -2,19 +2,19 @@ import { createFileRoute } from "@tanstack/react-router"
 import { Effect } from "effect"
 import { Component } from "effect-fc"
 import { runtime } from "@/runtime"
-import { Todos } from "@/todo/Todos"
+import { TodosState } from "@/todo/TodosState"
-import { TodosState } from "@/todo/TodosState.service"
+import { TodosView } from "@/todo/TodosView"
 
 
 const TodosStateLive = TodosState.Default("todos")
 
-const Index = Component.makeUntraced("Index")(function*() {
+const Index = Component.make("IndexView")(function*() {
-    const TodosFC = yield* Effect.provide(
+    const Todos = yield* Effect.provide(
-        Todos,
+        TodosView.use,
-        yield* Component.useContext(TodosStateLive),
+        yield* Component.useContextFromLayer(TodosStateLive),
     )
 
-    return <TodosFC />
+    return <Todos />
 }).pipe(
     Component.withRuntime(runtime.context)
 )

packages/example/src/routes/query.tsx

@@ -0,0 +1,117 @@
+import { HttpClient, type HttpClientError } from "@effect/platform"
+import { Button, Container, Flex, Heading, Slider, Text } from "@radix-ui/themes"
+import { createFileRoute } from "@tanstack/react-router"
+import { Array, Cause, Chunk, Console, Effect, flow, Match, Option, Schema, Stream, SubscriptionRef } from "effect"
+import { Component, ErrorObserver, Lens, Mutation, Query, Result, Subscribable } from "effect-fc"
+import { runtime } from "@/runtime"
+
+
+const Post = Schema.Struct({
+    userId: Schema.Int,
+    id: Schema.Int,
+    title: Schema.String,
+    body: Schema.String,
+})
+
+const ResultView = Component.make("ResultView")(function*() {
+    const runPromise = yield* Component.useRunPromise()
+
+    const [idLens, query, mutation] = yield* Component.useOnMount(() => Effect.gen(function*() {
+        const idLens = Lens.fromSubscriptionRef(yield* SubscriptionRef.make(1))
+        const key = Stream.map(idLens.changes, id => [id] as const)
+
+        const query = yield* Query.service({
+            key,
+            f: ([id]) => HttpClient.HttpClient.pipe(
+                Effect.tap(Effect.sleep("500 millis")),
+                Effect.andThen(client => client.get(`https://jsonplaceholder.typicode.com/posts/${ id }`)),
+                Effect.andThen(response => response.json),
+                Effect.andThen(Schema.decodeUnknown(Post)),
+            ),
+            staleTime: "10 seconds",
+        })
+
+        const mutation = yield* Mutation.make({
+            f: ([id]: readonly [id: number]) => HttpClient.HttpClient.pipe(
+                Effect.tap(Effect.sleep("500 millis")),
+                Effect.andThen(client => client.get(`https://jsonplaceholder.typicode.com/posts/${ id }`)),
+                Effect.andThen(response => response.json),
+                Effect.andThen(Schema.decodeUnknown(Post)),
+            ),
+        })
+
+        return [idLens, query, mutation] as const
+    }))
+
+    const [id, setId] = yield* Lens.useState(idLens)
+    const [queryResult, mutationResult] = yield* Subscribable.useAll([query.result, mutation.result])
+
+    yield* Component.useOnMount(() => ErrorObserver.ErrorObserver<HttpClientError.HttpClientError>().pipe(
+        Effect.andThen(observer => observer.subscribe),
+        Effect.andThen(Stream.fromQueue),
+        Stream.unwrapScoped,
+        Stream.runForEach(flow(
+            Cause.failures,
+            Chunk.findFirst(e => e._tag === "RequestError" || e._tag === "ResponseError"),
+            Option.match({
+                onSome: e => Console.log("ResultView HttpClient error", e),
+                onNone: () => Effect.void,
+            }),
+        )),
+        Effect.forkScoped,
+    ))
+
+    return (
+        <Container>
+            <Flex direction="column" align="center" gap="2">
+                <Slider
+                    value={[id]}
+                    onValueChange={flow(Array.head, Option.getOrThrow, setId)}
+                />
+
+                <div>
+                    {Match.value(queryResult).pipe(
+                        Match.tag("Running", () => <Text>Loading...</Text>),
+                        Match.tag("Success", result => <>
+                            <Heading>{result.value.title}</Heading>
+                            <Text>{result.value.body}</Text>
+                            {Result.hasRefreshingFlag(result) && <Text>Refreshing...</Text>}
+                        </>),
+                        Match.tag("Failure", result =>
+                            <Text>An error has occured: {result.cause.toString()}</Text>
+                        ),
+                        Match.orElse(() => <></>),
+                    )}
+                </div>
+
+                <Flex direction="row" justify="center" align="center" gap="1">
+                    <Button onClick={() => runPromise(query.refresh)}>Refresh</Button>
+                    <Button onClick={() => runPromise(query.invalidateCache)}>Invalidate cache</Button>
+                </Flex>
+
+                <div>
+                    {Match.value(mutationResult).pipe(
+                        Match.tag("Running", () => <Text>Loading...</Text>),
+                        Match.tag("Success", result => <>
+                            <Heading>{result.value.title}</Heading>
+                            <Text>{result.value.body}</Text>
+                            {Result.hasRefreshingFlag(result) && <Text>Refreshing...</Text>}
+                        </>),
+                        Match.tag("Failure", result =>
+                            <Text>An error has occured: {result.cause.toString()}</Text>
+                        ),
+                        Match.orElse(() => <></>),
+                    )}
+                </div>
+
+                <Flex direction="row" justify="center" align="center" gap="1">
+                    <Button onClick={() => runPromise(Effect.andThen(Lens.get(idLens), id => mutation.mutate([id])))}>Mutate</Button>
+                </Flex>
+            </Flex>
+        </Container>
+    )
+})
+
+export const Route = createFileRoute("/query")({
+    component: Component.withRuntime(ResultView, runtime.context)
+})

packages/example/src/routes/result.tsx

@@ -0,0 +1,60 @@
+import { HttpClient, type HttpClientError } from "@effect/platform"
+import { Container, Heading, Text } from "@radix-ui/themes"
+import { createFileRoute } from "@tanstack/react-router"
+import { Cause, Chunk, Console, Effect, flow, Match, Option, Schema, Stream } from "effect"
+import { Component, ErrorObserver, Result, Subscribable } from "effect-fc"
+import { runtime } from "@/runtime"
+
+
+const Post = Schema.Struct({
+    userId: Schema.Int,
+    id: Schema.Int,
+    title: Schema.String,
+    body: Schema.String,
+})
+
+const ResultView = Component.makeUntraced("Result")(function*() {
+    const [resultSubscribable] = yield* Component.useOnMount(() => HttpClient.HttpClient.pipe(
+        Effect.andThen(client => client.get("https://jsonplaceholder.typicode.com/posts/1")),
+        Effect.andThen(response => response.json),
+        Effect.andThen(Schema.decodeUnknown(Post)),
+        Effect.tap(Effect.sleep("250 millis")),
+        Result.forkEffect,
+    ))
+    const [result] = yield* Subscribable.useAll([resultSubscribable])
+
+    yield* Component.useOnMount(() => ErrorObserver.ErrorObserver<HttpClientError.HttpClientError>().pipe(
+        Effect.andThen(observer => observer.subscribe),
+        Effect.andThen(Stream.fromQueue),
+        Stream.unwrapScoped,
+        Stream.runForEach(flow(
+            Cause.failures,
+            Chunk.findFirst(e => e._tag === "RequestError" || e._tag === "ResponseError"),
+            Option.match({
+                onSome: e => Console.log("ResultView HttpClient error", e),
+                onNone: () => Effect.void,
+            }),
+        )),
+        Effect.forkScoped,
+    ))
+
+    return (
+        <Container>
+            {Match.value(result).pipe(
+                Match.tag("Running", () => <Text>Loading...</Text>),
+                Match.tag("Success", result => <>
+                    <Heading>{result.value.title}</Heading>
+                    <Text>{result.value.body}</Text>
+                </>),
+                Match.tag("Failure", result =>
+                    <Text>An error has occured: {result.cause.toString()}</Text>
+                ),
+                Match.orElse(() => <></>),
+            )}
+        </Container>
+    )
+})
+
+export const Route = createFileRoute("/result")({
+    component: Component.withRuntime(ResultView, runtime.context)
+})

packages/example/src/todo/EditTodoView.tsx

@@ -0,0 +1,88 @@
+import { Box, Flex, IconButton } from "@radix-ui/themes"
+import { Effect } from "effect"
+import { Component, Form, Subscribable, SynchronizedForm } from "effect-fc"
+import { FaArrowDown, FaArrowUp } from "react-icons/fa"
+import { FaDeleteLeft } from "react-icons/fa6"
+import { TextFieldFormInputView } from "@/lib/form/TextFieldFormInputView"
+import { TextFieldOptionalFormInputView } from "@/lib/form/TextFieldOptionalFormInputView"
+import { TodoFormSchema } from "./TodoFormSchema"
+import { TodosState } from "./TodosState"
+
+
+export interface EditTodoViewProps {
+    readonly id: string
+}
+
+export class EditTodoView extends Component.make("TodoView")(function*(props: EditTodoViewProps) {
+    const state = yield* TodosState
+
+    const [
+        indexSubscribable,
+        contentField,
+        completedAtField,
+    ] = yield* Component.useOnChange(() => Effect.gen(function*() {
+        const indexSubscribable = state.getIndexSubscribable(props.id)
+
+        const form = yield* SynchronizedForm.service({
+            schema: TodoFormSchema,
+            target: state.getElementLens(props.id),
+        })
+
+        return [
+            indexSubscribable,
+            Form.focusObjectOn(form, "content"),
+            Form.focusObjectOn(form, "completedAt"),
+        ] as const
+    }), [props.id])
+
+    const [index, size] = yield* Subscribable.useAll([
+        indexSubscribable,
+        state.sizeSubscribable,
+    ])
+
+    const runSync = yield* Component.useRunSync()
+    const TextFieldFormInput = yield* TextFieldFormInputView.use
+    const TextFieldOptionalFormInput = yield* TextFieldOptionalFormInputView.use
+
+
+    return (
+        <Flex direction="row" align="center" gap="2">
+            <Box flexGrow="1">
+                <Flex direction="column" align="stretch" gap="2">
+                    <TextFieldFormInput
+                        form={contentField}
+                        debounce="250 millis"
+                    />
+
+                    <Flex direction="row" justify="center" align="center" gap="2">
+                        <TextFieldOptionalFormInput
+                            form={completedAtField}
+                            type="datetime-local"
+                            defaultValue=""
+                        />
+                    </Flex>
+                </Flex>
+            </Box>
+
+            <Flex direction="column" justify="center" align="center" gap="1">
+                <IconButton
+                    disabled={index <= 0}
+                    onClick={() => runSync(state.moveLeft(props.id))}
+                >
+                    <FaArrowUp />
+                </IconButton>
+
+                <IconButton
+                    disabled={index >= size - 1}
+                    onClick={() => runSync(state.moveRight(props.id))}
+                >
+                    <FaArrowDown />
+                </IconButton>
+
+                <IconButton onClick={() => runSync(state.remove(props.id))}>
+                    <FaDeleteLeft />
+                </IconButton>
+            </Flex>
+        </Flex>
+    )
+}) {}

packages/example/src/todo/NewTodoView.tsx

@@ -0,0 +1,78 @@
+import { Box, Button, Flex } from "@radix-ui/themes"
+import { GetRandomValues, makeUuid4 } from "@typed/id"
+import { Chunk, type DateTime, Effect, Option, Schema } from "effect"
+import { Component, Form, Lens, SubmittableForm, Subscribable } from "effect-fc"
+import * as Domain from "@/domain"
+import { TextFieldFormInputView } from "@/lib/form/TextFieldFormInputView"
+import { TextFieldOptionalFormInputView } from "@/lib/form/TextFieldOptionalFormInputView"
+import { TodoFormSchema } from "./TodoFormSchema"
+import { TodosState } from "./TodosState"
+
+
+const makeTodo = makeUuid4.pipe(
+    Effect.map(id => Domain.Todo.Todo.make({
+        id,
+        content: "",
+        completedAt: Option.none(),
+    })),
+    Effect.provide(GetRandomValues.CryptoRandom),
+)
+
+
+export class NewTodoView extends Component.make("NewTodoView")(function*() {
+    const state = yield* TodosState
+
+    const [
+        form,
+        contentField,
+        completedAtField,
+    ] = yield* Component.useOnMount(() => Effect.gen(function*() {
+        const form = yield* SubmittableForm.service({
+            schema: TodoFormSchema,
+            initialEncodedValue: yield* Schema.encode(TodoFormSchema)(yield* makeTodo),
+            f: ([todo, form]) => Lens.update(state.lens, Chunk.prepend(todo)).pipe(
+                Effect.andThen(makeTodo),
+                Effect.andThen(Schema.encode(TodoFormSchema)),
+                Effect.andThen(v => Lens.set(form.encodedValue, v)),
+            ),
+        })
+
+        return [
+            form,
+            Form.focusObjectOn(form, "content"),
+            Form.focusObjectOn(form, "completedAt"),
+        ] as const
+    }))
+
+    const [canCommit] = yield* Subscribable.useAll([form.canCommit])
+
+    const runPromise = yield* Component.useRunPromise<DateTime.CurrentTimeZone>()
+    const TextFieldFormInput = yield* TextFieldFormInputView.use
+    const TextFieldOptionalFormInput = yield* TextFieldOptionalFormInputView.use
+
+
+    return (
+        <Flex direction="row" align="center" gap="2">
+            <Box flexGrow="1">
+                <Flex direction="column" align="stretch" gap="2">
+                    <TextFieldFormInput
+                        form={contentField}
+                        debounce="250 millis"
+                    />
+
+                    <Flex direction="row" justify="center" align="center" gap="2">
+                        <TextFieldOptionalFormInput
+                            form={completedAtField}
+                            type="datetime-local"
+                            defaultValue=""
+                        />
+
+                        <Button disabled={!canCommit} onClick={() => void runPromise(form.submit)}>
+                            Add
+                        </Button>
+                    </Flex>
+                </Flex>
+            </Box>
+        </Flex>
+    )
+}) {}

packages/example/src/todo/Todo.tsx

@@ -1,136 +0,0 @@
-import { Box, Button, Flex, IconButton } from "@radix-ui/themes"
-import { GetRandomValues, makeUuid4 } from "@typed/id"
-import { Chunk, Effect, Match, Option, Ref, Runtime, 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 { TextFieldFormInput } from "@/lib/form/TextFieldFormInput"
-import { DateTimeUtcFromZonedInput } from "@/lib/schema"
-import { TodosState } from "./TodosState.service"
-
-
-const TodoFormSchema = Schema.compose(Schema.Struct({
-    ...Domain.Todo.Todo.fields,
-    completedAt: Schema.OptionFromSelf(DateTimeUtcFromZonedInput),
-}), Domain.Todo.Todo)
-
-const makeTodo = makeUuid4.pipe(
-    Effect.map(id => Domain.Todo.Todo.make({
-        id,
-        content: "",
-        completedAt: Option.none(),
-    })),
-    Effect.provide(GetRandomValues.CryptoRandom),
-)
-
-
-export type TodoProps = (
-    | { readonly _tag: "new" }
-    | { readonly _tag: "edit", readonly id: string }
-)
-
-export class Todo extends Component.makeUntraced("Todo")(function*(props: TodoProps) {
-    const runtime = yield* Effect.runtime()
-    const state = yield* TodosState
-
-    const [
-        indexRef,
-        form,
-        contentField,
-        completedAtField,
-    ] = yield* Component.useOnChange(() => Effect.gen(function*() {
-        const indexRef = Match.value(props).pipe(
-            Match.tag("new", () => Subscribable.make({ get: Effect.succeed(-1), changes: Stream.make(-1) })),
-            Match.tag("edit", ({ id }) => state.getIndexSubscribable(id)),
-            Match.exhaustive,
-        )
-
-        const form = yield* Form.service({
-            schema: TodoFormSchema,
-            initialEncodedValue: yield* Schema.encode(TodoFormSchema)(
-                yield* Match.value(props).pipe(
-                    Match.tag("new", () => makeTodo),
-                    Match.tag("edit", ({ id }) => state.getElementRef(id)),
-                    Match.exhaustive,
-                )
-            ),
-            onSubmit: function(todo) {
-                return Match.value(props).pipe(
-                    Match.tag("new", () => Ref.update(state.ref, Chunk.prepend(todo)).pipe(
-                        Effect.andThen(makeTodo),
-                        Effect.andThen(Schema.encode(TodoFormSchema)),
-                        Effect.andThen(v => Ref.set(this.encodedValueRef, v)),
-                    )),
-                    Match.tag("edit", ({ id }) => Ref.set(state.getElementRef(id), todo)),
-                    Match.exhaustive,
-                )
-            },
-            autosubmit: props._tag === "edit",
-            debounce: "250 millis",
-        })
-
-        return [
-            indexRef,
-            form,
-            Form.field(form, ["content"]),
-            Form.field(form, ["completedAt"]),
-        ] as const
-    }), [props._tag, props._tag === "edit" ? props.id : undefined])
-
-    const [index, size, canSubmit] = yield* Subscribable.useSubscribables(
-        indexRef,
-        state.sizeSubscribable,
-        form.canSubmitSubscribable,
-    )
-    const submit = yield* Form.useSubmit(form)
-    const TextFieldFormInputFC = yield* TextFieldFormInput
-
-
-    return (
-        <Flex direction="row" align="center" gap="2">
-            <Box flexGrow="1">
-                <Flex direction="column" align="stretch" gap="2">
-                    <TextFieldFormInputFC field={contentField} />
-
-                    <Flex direction="row" justify="center" align="center" gap="2">
-                        <TextFieldFormInputFC
-                            optional
-                            field={completedAtField}
-                            type="datetime-local"
-                            defaultValue=""
-                        />
-
-                        {props._tag === "new" &&
-                            <Button disabled={!canSubmit} onClick={() => submit()}>
-                                Add
-                            </Button>
-                        }
-                    </Flex>
-                </Flex>
-            </Box>
-
-            {props._tag === "edit" &&
-                <Flex direction="column" justify="center" align="center" gap="1">
-                    <IconButton
-                        disabled={index <= 0}
-                        onClick={() => Runtime.runSync(runtime)(state.moveLeft(props.id))}
-                    >
-                        <FaArrowUp />
-                    </IconButton>
-
-                    <IconButton
-                        disabled={index >= size - 1}
-                        onClick={() => Runtime.runSync(runtime)(state.moveRight(props.id))}
-                    >
-                        <FaArrowDown />
-                    </IconButton>
-
-                    <IconButton onClick={() => Runtime.runSync(runtime)(state.remove(props.id))}>
-                        <FaDeleteLeft />
-                    </IconButton>
-                </Flex>
-            }
-        </Flex>
-    )
-}) {}

packages/example/src/todo/TodoFormSchema.ts

@@ -0,0 +1,9 @@
+import { Schema } from "effect"
+import * as Domain from "@/domain"
+import { DateTimeUtcFromZonedInput } from "@/lib/schema"
+
+
+export const TodoFormSchema = Schema.compose(Schema.Struct({
+    ...Domain.Todo.Todo.fields,
+    completedAt: Schema.OptionFromSelf(DateTimeUtcFromZonedInput),
+}), Domain.Todo.Todo)

packages/example/src/todo/TodosState.ts

@@ -1,7 +1,7 @@
 import { KeyValueStore } from "@effect/platform"
 import { BrowserKeyValueStore } from "@effect/platform-browser"
 import { Chunk, Console, Effect, Option, Schema, Stream, SubscriptionRef } from "effect"
-import { Subscribable, SubscriptionSubRef } from "effect-fc"
+import { Lens, Subscribable } from "effect-fc"
 import { Todo } from "@/domain"
 
 
@@ -30,27 +30,29 @@ export class TodosState extends Effect.Service<TodosState>()("TodosState", {
                 : kv.remove(key)
         )
 
-        const ref = yield* SubscriptionRef.make(yield* readFromLocalStorage)
+        const lens = Lens.fromSubscriptionRef(yield* SubscriptionRef.make(yield* readFromLocalStorage))
-        yield* Effect.forkScoped(ref.changes.pipe(
+        yield* Effect.forkScoped(lens.changes.pipe(
             Stream.debounce("500 millis"),
             Stream.runForEach(saveToLocalStorage),
         ))
-        yield* Effect.addFinalizer(() => ref.pipe(
+        yield* Effect.addFinalizer(() => Lens.get(lens).pipe(
             Effect.andThen(saveToLocalStorage),
             Effect.ignore,
         ))
 
-        const sizeSubscribable = Subscribable.make({
+        const sizeSubscribable = Subscribable.map(lens, Chunk.size)
-            get: Effect.andThen(ref, Chunk.size),
-            get changes() { return Stream.map(ref.changes, Chunk.size) },
-        })
-        const getElementRef = (id: string) => SubscriptionSubRef.makeFromChunkFindFirst(ref, v => v.id === id)
-        const getIndexSubscribable = (id: string) => Subscribable.make({
-            get: Effect.flatMap(ref, Chunk.findFirstIndex(v => v.id === id)),
-            get changes() { return Stream.flatMap(ref.changes, Chunk.findFirstIndex(v => v.id === id)) },
-        })
 
-        const moveLeft = (id: string) => SubscriptionRef.updateEffect(ref, todos => Effect.Do.pipe(
+        const getElementLens = (id: string) => Lens.mapEffect(
+            lens,
+            Chunk.findFirst(v => v.id === id),
+            (a, b) => Effect.flatMap(
+                Chunk.findFirstIndex(a, v => v.id === id),
+                i => Chunk.replaceOption(a, i, b),
+            )
+        )
+        const getIndexSubscribable = (id: string) => Subscribable.mapEffect(lens, Chunk.findFirstIndex(v => v.id === id))
+
+        const moveLeft = (id: string) => Lens.updateEffect(lens, todos => Effect.Do.pipe(
             Effect.bind("index", () => Chunk.findFirstIndex(todos, v => v.id === id)),
             Effect.bind("todo", ({ index }) => Chunk.get(todos, index)),
             Effect.bind("previous", ({ index }) => Chunk.get(todos, index - 1)),
@@ -62,7 +64,7 @@ export class TodosState extends Effect.Service<TodosState>()("TodosState", {
                 : todos
             ),
         ))
-        const moveRight = (id: string) => SubscriptionRef.updateEffect(ref, todos => Effect.Do.pipe(
+        const moveRight = (id: string) => Lens.updateEffect(lens, todos => Effect.Do.pipe(
             Effect.bind("index", () => Chunk.findFirstIndex(todos, v => v.id === id)),
             Effect.bind("todo", ({ index }) => Chunk.get(todos, index)),
             Effect.bind("next", ({ index }) => Chunk.get(todos, index + 1)),
@@ -74,15 +76,15 @@ export class TodosState extends Effect.Service<TodosState>()("TodosState", {
                 : todos
             ),
         ))
-        const remove = (id: string) => SubscriptionRef.updateEffect(ref, todos => Effect.andThen(
+        const remove = (id: string) => Lens.updateEffect(lens, todos => Effect.andThen(
             Chunk.findFirstIndex(todos, v => v.id === id),
             index => Chunk.remove(todos, index),
         ))
 
         return {
-            ref,
+            lens,
             sizeSubscribable,
-            getElementRef,
+            getElementLens,
             getIndexSubscribable,
             moveLeft,
             moveRight,

packages/example/src/todo/TodosView.tsx

@@ -1,30 +1,32 @@
 import { Container, Flex, Heading } from "@radix-ui/themes"
 import { Chunk, Console, Effect } from "effect"
 import { Component, Subscribable } from "effect-fc"
-import { Todo } from "./Todo"
+import { EditTodoView } from "./EditTodoView"
-import { TodosState } from "./TodosState.service"
+import { NewTodoView } from "./NewTodoView"
+import { TodosState } from "./TodosState"
 
 
-export class Todos extends Component.makeUntraced("Todos")(function*() {
+export class TodosView extends Component.make("TodosView")(function*() {
     const state = yield* TodosState
-    const [todos] = yield* Subscribable.useSubscribables(state.ref)
+    const [todos] = yield* Subscribable.useAll([state.lens])
 
     yield* Component.useOnMount(() => Effect.andThen(
         Console.log("Todos mounted"),
         Effect.addFinalizer(() => Console.log("Todos unmounted")),
     ))
 
-    const TodoFC = yield* Todo
+    const NewTodo = yield* NewTodoView.use
+    const EditTodo = yield* EditTodoView.use
 
     return (
         <Container>
             <Heading align="center">Todos</Heading>
 
             <Flex direction="column" align="stretch" gap="2" mt="2">
-                <TodoFC _tag="new" />
+                <NewTodo />
 
                 {Chunk.map(todos, todo =>
-                    <TodoFC key={todo.id} _tag="edit" id={todo.id} />
+                    <EditTodo key={todo.id} id={todo.id} />
                 )}
             </Flex>
         </Container>