Thilawyn/effect-lens
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Update README
Lint / lint (push) Successful in 26s
Details

Browse Source
This commit is contained in:
Julien Valverdé
2026-07-16 22:00:17 +02:00
parent 558330c451
commit cf6c082672
2 changed files with 22 additions and 25 deletions
Download Patch File Download Diff File Expand all files Collapse all files
packages/effect-lens-next/README.md
+20 -20
View File
@@ -4,13 +4,13 @@ A Lens type for [Effect](https://effect.website/) to easily manage nested state.
## Install ## Install
``` ```
npm install effect-lens@beta effect@4.0.0-beta.85 npm install effect-lens@beta effect@4.0.0-beta.98
yarn add effect-lens@beta effect@4.0.0-beta.85 yarn add effect-lens@beta effect@4.0.0-beta.98
bun add effect-lens@beta effect@4.0.0-beta.85 bun add effect-lens@beta effect@4.0.0-beta.98
``` ```
## Peer dependencies ## Peer dependencies
- `effect` 4.0.0-beta.85 - `effect` 4.0.0-beta.98
## Quickstart ## Quickstart
@@ -64,7 +64,7 @@ You can also create Lenses manually using `make` by providing:
- `get`: an effect that reads the current value, - `get`: an effect that reads the current value,
- `changes`: a stream of value changes, - `changes`: a stream of value changes,
- `commit`: an effectful write primitive, - `commit`: an effectful write primitive,
- `lock`: an effect that produces the lock used to serialize writes. - `lock`: an effect that produces the lock used to serialize writes and preserve atomicity.
You can get pretty creative! Here's an example of a Lens that points to a specific key of the browser `LocalStorage`: You can get pretty creative! Here's an example of a Lens that points to a specific key of the browser `LocalStorage`:
```typescript ```typescript
@@ -101,9 +101,6 @@ const lens = Effect.all([
) )
``` ```
Note: while Lens supports asynchronous effects for the proxy logic, we would recommend keeping them synchronous to preserve atomicity.
### Focusing ### Focusing
Lenses can focus on a nested part of the data type they point to. Lenses can focus on a nested part of the data type they point to.
@@ -242,30 +239,33 @@ const nameLens = lens.pipe(
### View ### View
Effect 4 no longer provides its former `Subscribable` and `Readable` abstractions. This library provides a `View` interface, which you can use as a constraint to allow some parts of your app to only read and subscribe to the Lenses you provide them: A `View` is a read-only, reactive view of a value: it lets you read the current value and observe subsequent changes. Every `Lens` is also a `View`, which you can use as a constraint to allow some parts of your app to only read and subscribe to the Lenses you provide them. It replaces Effect v3's `Subscribable` module:
```typescript ```typescript
const ref = yield* SubscriptionRef.make<{ const ref = yield* SubscriptionRef.make<{
readonly users: readonly User[] readonly users: readonly User[]
}>({ users: [...] }) }>({ users: [] })
const someFunctionThatShouldOnlyHaveReadonlyAccessToTheState = ( const logUserCount = (users: View.View<readonly User[]>) =>
usersView: View.View<readonly User[], never, never> Effect.gen(function*() {
) => Effect.gen(function*() { const userCount = View.map(users, users => users.length)
// Do whatever yield* Console.log(`There are ${yield* userCount.get} users`)
const usersCountView = View.map(usersView, a => a.length) yield* Stream.runForEach(
const users = yield* usersView.get userCount.changes,
yield* Effect.forkScoped(Stream.runForEach(usersView.changes, ...)) count => Console.log(`There are now ${count} users`),
)
}) })
const lens = ref.pipe( const usersLens = ref.pipe(
Lens.fromSubscriptionRef, Lens.fromSubscriptionRef,
Lens.focusObjectOn("users"), Lens.focusObjectOn("users"),
) )
yield* someFunctionThatShouldOnlyHaveReadonlyAccessToTheState(lens) yield* Effect.forkScoped(logUserCount(usersLens))
``` ```
Use `Lens.asView` when you want to make that read-only boundary explicit.
#### Focusing #### Focusing
This library provides a `View` module with value and error transforms, recovery (`catch`, `catchCause`, `orElse`, `orElseSucceed`, and `retry`), and transforms to narrow the focus of `View`'s, same as Lenses: Views can be focused in the same way as Lenses. The `View` module also provides value and error transforms, plus recovery (`catch`, `catchCause`, `orElse`, `orElseSucceed`, and `retry`):
```typescript ```typescript
import { View } from "effect-lens" import { View } from "effect-lens"
packages/effect-lens/README.md
+1 -4
View File
@@ -64,7 +64,7 @@ You can also create Lenses manually using `make` by providing:
- `get`: an effect that reads the current value, - `get`: an effect that reads the current value,
- `changes`: a stream of value changes, - `changes`: a stream of value changes,
- `commit`: an effectful write primitive, - `commit`: an effectful write primitive,
- `lock`: an effect that produces the lock used to serialize writes. - `lock`: an effect that produces the lock used to serialize writes and preserve atomicity.
You can get pretty creative! Here's an example of a Lens that points to a specific key of the browser `LocalStorage`: You can get pretty creative! Here's an example of a Lens that points to a specific key of the browser `LocalStorage`:
```typescript ```typescript
@@ -101,9 +101,6 @@ const lens = Effect.all([
) )
``` ```
Note: while Lens supports asynchronous effects for the proxy logic, we would recommend keeping them synchronous to preserve atomicity.
### Focusing ### Focusing
Lenses can focus on a nested part of the data type they point to. Lenses can focus on a nested part of the data type they point to.