WeakStore

Wrapper for JavaScript WeakMap

WeakStore adds some additional functionality on top of WeakMap.

1. WeakStore distinguishes between initializing (init) a (key, value) pair and resetting the key to a different value (set), whereas WeakMap doesn't. This means you can use the WeakStore abstraction without having to check whether the key already exists. This is because the method that you call (init or set) marks your intention and does it for you.

2. You can use the WeakStore methods in a functional programming pattern, which you can't with WeakMap. For instance, you can create a new function const getPurse = weakStore.get and you can do myArray.map(weakStore.get). You can't do either of these with WeakMap, because the WeakMap methods are not tied to a particular WeakMap instance.

See @agoric/store for the wrapper around JavaScript's Map abstraction.