Add Effect v4 version

packages/effect-fc-next/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 | EW, 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.strictEqual()),
+            v => Effect.sync(() => setReactStateValue(v)),
+        )
+    ), [lens])
+
+    const setValue = yield* Component.useCallbackSync(
+        (setStateAction: React.SetStateAction<A>) => Effect.tap(
+            Lens.updateAndGet(lens, prevState => SetStateAction.value(setStateAction, prevState)),
+            v => Effect.sync(() => 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.strictEqual()),
+        v => Effect.sync(() => setValue(v)),
+    )), [setValue])
+    yield* Component.useReactEffect(() => Lens.set(lens, value), [value])
+
+    return lens
+})