weakerable

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A tiny ESM module that provides iterable WeakMap and WeakSet wrappers.

weakerable keeps the weak ownership semantics of native weak collections while letting you iterate over keys, values, or entries that are still reachable.

Features

• Map implements the familiar WeakMap API plus [Symbol.iterator]().
• Set implements the familiar WeakSet API plus [Symbol.iterator]().
• Entries are tracked through WeakRef, so collected keys disappear from future iterations.
• Constructors accept iterables, matching Map and Set ergonomics.
• TypeScript declarations are included.

Usage

// import Map from "weakerable/map";
// import Set from "weakerable/set";
import { Map, Set } from "weakerable";
// or import * as weak from "weakerable"; new weak.Map([...]);

const key = {};

const cache = new Map([[key, "value"]]);
const seen = new Set([key]);

console.log(cache.get(key)); // "value"
console.log([...cache]);     // [[key, "value"]]
console.log([...seen]);      // [key]

You can also import the individual implementations:

import Map from "weakerable/map";
import Set from "weakerable/set";

Reason

I already use not-so-weak on occasion, but I recently realized that all I needed was an iterable WeakSet or WeakMap.

With this module's simpler approach:

• code size stays minimal: iteration is the only extra feature
• performance stays as close as possible to native WeakMap and WeakSet
• there is no FinalizationRegistry orchestration: stale references are pruned when the collection is iterated

That's it. If you need a minimal iterable weak container, this should be your final stop.