WeakishMap

It’s like WeakMap but it supports non-objects.

Installation

Requires Node.js 6.0.0 or above.

npm i weakish-map

API

The module exposes a single class.

Constructor

The constructor supports the following arguments:

1. Optional: items (iterable): Initial key-value pairs for the map.
2. Optional: Object argument:
   • StrongMap (class): Set this if you have a custom Map class you want to use for storing non-objects. Defaults to the built-in Map.
   • strongMap (function): A callback that creates a new map for storing non-objects. Defaults to a function that creates a new StrongMap.
   • WeakMap (class): Set this if you have a custom WeakMap class you want to use for storing objects. Defaults to the built-in WeakMap.
   • weakMap (function): A callback that creates a new weak map for storing objects. Defaults to a function that creates a new WeakMap.

Methods

Instances of this class have the following methods, which behave just like the corresponding methods on Map and WeakMap:

• get()
• set()
• has()
• delete()
• clear()

Instances also have methods which only work on non-objects:

• entries()
• forEach()
• keys()
• values()

Example

// Before
const map1 = new WeakMap()
map1.set({}, 'value')
map1.set('key', 'value') // Uncaught TypeError: Invalid value used as weak map key

// After
const WeakishMap = require('weakish-map')
const map2 = new WeakishMap()
map2.set({}, 'value')
map2.set('key', 'value')
map2.get('key') // 'value'
Array.from(map2.keys()) // ['key']

Related

• weakish-set