https://github.com/lamansky/m-o
A Node.js package of has/get/set/delete methods that work on both Maps and Objects.
https://github.com/lamansky/m-o
Last synced: 3 months ago
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A Node.js package of has/get/set/delete methods that work on both Maps and Objects.
- Host: GitHub
- URL: https://github.com/lamansky/m-o
- Owner: lamansky
- License: mit
- Created: 2017-11-28T14:10:55.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2018-01-22T10:42:01.000Z (over 8 years ago)
- Last Synced: 2025-08-05T08:19:29.498Z (11 months ago)
- Language: JavaScript
- Homepage:
- Size: 19.5 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- License: license.txt
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README
# m-o
A collection of functions that work on both Maps and Objects, letting you write code that can handle either, if that’s your M.O.
The functions are: `has`, `hasIn`, `get`, `getIn`, `set`, `edit`, `delete`, `construct`, `reconstruct`, `entries`, `entriesArray`, `keys`, `keysArray`, `values`, and `valuesArray`.
## Installation
Requires [Node.js](https://nodejs.org/) 7.0.0 or above.
```bash
npm install m-o --save
```
The module exports an object with multiple methods.
## Usage
Nota Bene: Maps can accept keys of any type, but Objects cannot. If you expect your code to work with both, then you should only use strings/numbers/symbols as keys.
```javascript
const mo = require('m-o')
const map = new Map()
const obj = {}
// Set
mo.set(map, 'hello', 'world')
mo.set(obj, 'hello', 'world')
// Has
mo.has(map, 'hello') // true
mo.has(obj, 'hello') // true
// Get
mo.get(map, 'hello') // 'world'
mo.get(obj, 'hello') // 'world'
// vs. the normal way:
map.get('hello') // 'world'
obj.hello // 'world'
// Edit
mo.edit(map, 'hello', value => value + '!')
mo.edit(obj, 'hello', value => value + '!')
mo.get(map, 'hello') // 'world!'
mo.get(obj, 'hello') // 'world!'
// Delete
mo.delete(map, 'hello') // true
mo.delete(obj, 'hello') // true
mo.delete(map, 'nonexistent') // false
mo.delete(obj, 'nonexistent') // false
// Entries
mo.entries(map) // MapIterator
mo.entries(obj) // ArrayIterator
// Construct a Map or an Object, depending on the class provided
const entries = [['hello', 'world']]
mo.construct(Object, entries) // {hello: 'world'}
mo.construct(Map, entries) // Map
class XMap extends Map {}
mo.construct(XMap, entries) // XMap
// Construct a new Map or Object having the same class as an existing object
mo.reconstruct(obj, entries) // {hello: 'world'}
mo.reconstruct(map, entries) // Map
mo.reconstruct(new XMap(), entries) // XMap
```
### Entries, Keys, and Values
The `Map` prototype has `entries()`, `keys()`, and `values()` methods which return iterators, whereas the global functions `Object.entries()`, `Object.keys()`, and `Object.values()` return arrays. The `m-o` module lets you remain consistent regardless of which type you’re dealing with. Use the `entries()`, `keys()`, and `values()` methods if you want iterators, and use `entriesArray()`, `keysArray()`, and `valuesArray()` if you want arrays.
### Accessing Prototype Properties
By default, `has` and `get` treat an object like a dictionary and therefore only access its own properties. If you want to access object prototype properties as well, use the `hasIn` or `getIn` methods instead. (With Maps, behavior is the same regardless of which set of methods you use.)
```javascript
typeof obj.toString // 'function'
typeof mo.get(obj, 'toString') // 'undefined'
typeof mo.getIn(obj, 'toString') // 'function'
mo.has(obj, 'toString') // false
mo.hasIn(obj, 'toString') // true
```