# lighter-type
> A lightweight JavaScript inheritance utility.
Latest version **2.2.1** (published 2016-07-31) · ISC license · 0 weekly downloads
## Install
```sh
npm install lighter-type
pnpm add lighter-type
yarn add lighter-type
bun add lighter-type
```
## Health
**Score 15/100 (F)** — status: abandoned.
Positive: no vulnerabilities.
Warnings: low downloads; no types; no esm support.
Negative: abandoned; low maintenance score.
## Facts
| | |
|---|---|
| Version | 2.2.1 |
| Published | 2016-07-31 |
| First published | 2015-09-12 |
| Weekly downloads | 0 |
| License | ISC |
| TypeScript types | none |
| Module format | CommonJS |
| Node | >=0.10.40 |
| Dependencies | 0 |
| Known vulnerabilities | 0 |
| Install scripts | no |
| GitHub stars | 0 |
| Author | Sam Eubank |
| Maintainers | zerious |
| Keywords | lighter, type, object, inheritance, prototype, prototypal, multiple, swiss, mixin, extend, decorate, init, constructor, hidden, enumerable, properties, fast, lightweight, minimal, resig, class, classy, util, inherits, modelo, augment, fiber, klass, proto, extends, decorator, super, sub, construct, lightweight, benchmarks, benchmark, bench, optimize, optimized |
## Links
- npm: https://www.npmjs.com/package/lighter-type
- Repository: https://github.com/lighterio/lighter-type
- Issues: https://github.com/lighterio/lighter-type/issues
- npm.io page: https://npm.io/package/lighter-type
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## Recent versions
- 2.2.1 (latest) — 2016-07-31
- 2.2.0 — 2016-07-25
- 2.1.1 — 2015-12-04
- 2.1.0 — 2015-11-09
- 2.0.0 — 2015-11-04
- 1.2.1 — 2015-10-20
- 1.2.0 — 2015-10-19
- 1.1.0 — 2015-09-29
- 1.0.0 — 2015-09-21
- 0.0.2 — 2015-09-19
- 0.0.1 — 2015-09-12
## README
# lighter-type
[](//gitter.im/lighterio/public)
[](//www.npmjs.com/package/lighter-type)
[](//www.npmjs.com/package/lighter-type)
[](//travis-ci.org/lighterio/lighter-type)
[](//coveralls.io/r/lighterio/lighter-type)
[](//www.npmjs.com/package/standard)
The `lighter-type` module is a prototypal inheritance utility with
[better performance](//github.com/lighterio/lighter-type/blob/master/BENCHMARKS.md)
than similar inheritance utilities.
It supports:
* Constructors
* Prototypal inheritance
* Multiple inheritance
* Non-enumerable property definitions
## Installation
From your project directory, install and save as a dependency:
```bash
npm install --save lighter-type
```
## Usage
The `lighter-type` module outputs a constructor with several methods.
- [Type.extend(prototypeProps[, constructorProps])](#typeextendprototypeprops-constructorprops)
- [Type.init(object[, overwrite][, args])](#typeinitobject-overwrite-args)
- [Type.decorate(object[, map][, overwrite])](#typedecorateobject-map-overwrite)
- [Type.include(type[, overwrite])](#typeincludetype-overwrite)
- [Type.is(type)](#typeistype)
- [Type.has(type)](#typehastype)
- [Type.hide(object, key, value)](#typehideobject-key-value)
### Type.extend([constructor], [prototypeProps], [constructorProps])
Define and return a sub type of the `Type` object, with a prototype decorated
with optional `prototypeProps` (a map of additional prototype properties) and optional
`constructorProps` (a map additional type properties. The sub type itself also inherits
the properties of its super type (such as the `extend` method).
When the `prototypeProps` argument includes a property called `init`, it is used as the
constructor for the sub type rather than being added as a prototype property.
```js
var Type = require('lighter-type')
// Construct a new person with a name.
var Person = Type.extend(function Person (name) {
this.name = name
}, {
// Give a person a default salutation of "Hello".
salutation: 'Hello',
// Greet a person with their defined salutation.
greet: function () {
console.log(this.salutation + ', ' + this.name + '!')
}
}, {
// Identify this type, if asked.
getTypeName: function () {
return 'Person'
}
})
// Make a Friend sub type by extending the Person type.
var Friend = Person.extend({
// Be a bit more informal with friends.
salutation: 'Hi'
}, {
// Identify this type, if asked.
getTypeName: function () {
return 'Friend'
}
})
// Instantiate Bob, and greet him.
var bob = new Person('Bob')
bob.greet()
//> "Hello, Bob!"
// Instantiate Joe, and greet him.
var joe = new Friend('Joe')
joe.greet()
//> "Hi, Joe!"
// Make sure a Friend is a Friend.
console.log(Friend.getTypeName())
//> "Friend"
```
Each type's prototype has `_super` property which references its parent
prototype, and each type has a `_super` property which references its
parent type.
```js
var Type = require('lighter-type')
var Robot = Type.extend({
bend: function (object) {
object.isBent = true
}
})
var Bender = Robot.extend({
bend: function (object) {
this._super.bend(object)
console.log('Bite my shiny metal ass.')
}
})
var beam = {}
var bender = new Bender()
bender.bend(beam)
//> Bite my shiny metal ass.
console.log(beam.isBent)
//> true
```
### Type.init(object[, overwrite][, args])
Decorate an object with the prototype of a `Type`, and call its constructor
on the object with an `args` array, unless `args` is `false`, in which case
the constructor will be skipped.
Any object that extends Type (such as
[lighter-emitter](//github.com/lighterio/lighter-emitter))
will inherit `Type.init` and other Type methods.
```js
// The `lighter-emitter` module extends `lighter-type`.
var Emitter = require('lighter-emitter')
// Make the `console` object into an emitter.
Emitter.init(console)
console.on('hi', function (name) {
console.log('Hi, ' + name + '!')
})
console.emit('hi', 'Sam')
//> Hi, Sam!
```
### Type.decorate(object[, map][, overwrite])
Decorate an `object` with a `map` of additional properties (or overriding
properties if `overwrite` is truthy). If the map is not specified, the `Type`
prototype will decorate the `object` prototype instead.
```js
var Type = require('lighter-type')
// Add a few methods to the Array object's prototype.
Type.decorate(Array.prototype, {
first: function () {
return this[0]
},
last: function () {
return this[this.length - 1]
},
sum: function () {
var s = 0
for (var i = 0, l = this.length; i < l; i++) {
s += this[i]
}
return s
}
})
// Create a plain old array of numbers.
var a = [1, 2, 3]
console.log(a.first())
//> 1
console.log(a.last())
//> 3
console.log(a.sum())
//> 6
```
### Type.include(type[, overwrite])
Implement multiple inheritance by decorating one Type's prototype with the
prototype properties of another.
```js
var Type = require('lighter-type')
// A vehicle might work on land or water.
var Vehicle = Type.extend({
// Return isLandVehicle as a boolean.
worksOnLand: function () {
return !!this.isLandVehicle
},
// Return isWaterVehicle as a boolean.
worksOnWater: function () {
return !!this.isWaterVehicle
}
})
// A car is a land vehicle.
var Car = Vehicle.extend({
isLandVehicle: true
})
// A boat is a water vehicle.
var Boat = Vehicle.extend({
isWaterVehicle: true
})
// A hovercraft is also a vehicle.
var Hovercraft = Vehicle.extend({})
// A hovercraft includes the functionality of a Car and a Boat.
Hovercraft.include(Car)
Hovercraft.include(Boat)
// Create a new Hovercraft.
var hovercraft = new Hovercraft()
console.log(hovercraft.worksOnLand())
//> true
console.log(hovercraft.worksOnWater())
//> true
```
### Type.is(type)
Check whether this Type is descended from another Type.
```js
var Foo = Type.extend({})
var Bar = Foo.extend({})
var Baz = Bar.extend({})
console.log(Baz.is(Foo))
//> true
console.log(Foo.is(Baz))
//> false
```
### Type.has(type)
Check whether this Type has acquired the functionality of another type
via the extend method or the include method.
```js
var Type = require('lighter-type')
// Create an object with a visible (i.e. enumerable) method.
var object = {
visible: function () {
console.log('I am visible.')
}
}
// Add a non-enumerable property called "hidden".
Type.hide(object, 'hidden', function () {
console.log('I am hidden.')
})
// Verify that the "hidden" method exists.
object.hidden()
//> "I exist."
// Verify that only the "visible" method is enumerable.
for (var key in object) {
console.log(key)
}
//> "visible"
```
### Type.hide(object, key, value)
Create a property of `object` named `key` with value `value`, and "hide" it by
making it non-enumerable.
```js
var Type = require('lighter-type')
// Create an object with a visible (i.e. enumerable) method.
var object = {
visible: function () {
console.log('I am visible.')
}
}
// Add a non-enumerable property called "hidden".
Type.hide(object, 'hidden', function () {
console.log('I am hidden.')
})
// Verify that the "hidden" method exists.
object.hidden()
//> "I exist."
// Verify that only the "visible" method is enumerable.
for (var key in object) {
console.log(key)
}
//> "visible"
```
## More on lighter-type...
* [Contributing](//github.com/lighterio/lighter-type/blob/master/CONTRIBUTING.md)
* [License (ISC)](//github.com/lighterio/lighter-type/blob/master/LICENSE.md)
* [Change Log](//github.com/lighterio/lighter-type/blob/master/CHANGELOG.md)
* [Benchmarks](//github.com/lighterio/lighter-type/blob/master/BENCHMARKS.md)
* [Roadmap](//github.com/lighterio/lighter-type/blob/master/ROADMAP.md)
---
_Source: https://npm.io/package/lighter-type · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._