Refactoring

packages/effect-fc/src/Memoized.ts

@@ -0,0 +1,42 @@
+import { type Equivalence, Function, Predicate } from "effect"
+import type * as Component from "./Component.js"
+
+
+export const TypeId: unique symbol = Symbol.for("effect-fc/Memoized")
+export type TypeId = typeof TypeId
+
+export interface Memoized<P> extends Memoized.Options<P> {
+    readonly [TypeId]: true
+}
+
+export namespace Memoized {
+    export interface Options<P> {
+        readonly propsAreEqual?: Equivalence.Equivalence<P>
+    }
+}
+
+
+export const isMemoized = (u: unknown): u is Memoized<any> => Predicate.hasProperty(u, TypeId)
+
+export const memo = <T extends Component.Component<any, any, any>>(
+    self: T
+): T & Memoized<Component.Component.Props<T>> => Object.setPrototypeOf(
+    { ...self, [TypeId]: true },
+    Object.getPrototypeOf(self),
+)
+
+export const withOptions: {
+    <T extends Component.Component<any, any, any> & Memoized<any>>(
+        options: Partial<Memoized.Options<Component.Component.Props<T>>>
+    ): (self: T) => T
+    <T extends Component.Component<any, any, any> & Memoized<any>>(
+        self: T,
+        options: Partial<Memoized.Options<Component.Component.Props<T>>>,
+    ): T
+} = Function.dual(2, <T extends Component.Component<any, any, any> & Memoized<any>>(
+    self: T,
+    options: Partial<Memoized.Options<Component.Component.Props<T>>>,
+): T => Object.setPrototypeOf(
+    { ...self, ...options },
+    Object.getPrototypeOf(self),
+))