@miyauci/memo/esm/memo.js

Memoization tools, TC39 proposal-function-memo implementation

// Copyright © 2023 Tomoki Miyauchi. All rights reserved. MIT license.
// This module is browser compatible.
// deno-lint-ignore-file ban-types no-explicit-any
import { compositeKey, emplace } from "./deps.js";
export function memo(fn, cache = new WeakMap(), keying) {
    const proxy = new Proxy(fn, {
        apply(target, thisArg, args) {
            const key = compositeKey(target, thisArg, ...keying ? keying(args) : args);
            const value = emplace(cache, key, {
                insert: () => Reflect.apply(target, thisArg, args),
            });
            return value;
        },
        construct(target, args, newTarget) {
            const key = compositeKey(target, newTarget, ...keying ? keying(args) : args);
            const value = emplace(cache, key, {
                insert: () => Reflect.construct(target, args, newTarget),
            });
            return value;
        },
    });
    return proxy;
}