Action-Type 

Type class specification for actions.

Index

- Ecosystem
- Specification
- Action
- API
- action
- isAction
- Nil
- List
- isList
- Related Libraries

Ecosystem

| Project | Description |
| :---------------------- | :----------------------------------------------------------------------------- |
| [Hoe] | An action emitter library for the DOM. |
| [Update Function Types] | Utilities for doing more complex operations based on Action and some State |
| [Match Action] | Switch-case for Actions |
| [Action Component] | A library to create components with Action and State |

[hoe]: https://github.com/tusharmath/hoe
[update function types]: https://github.com/tusharmath/update-function-types
[match action]: https://github.com/tusharmath/match-action
[action component]: https://github.com/tusharmath/action-component

Specification

1. An Action consists of two properties viz. type and value.
2. action.type is of type string or number.
3. action.value is of type any. It could also be of type Action
4. The object is an immutable and should never be updated.

Action Type

An action is an object which contains two properties — type and value.

``ts
interface Action {
type: string
value: T
}
`

API

action

A utility that helps in creating a new object of action type. The function is curried by default and provides type guarantee.

`ts
import {action} from 'action-type'

action('click', {x: 10, y: 20})

action('click')({x: 10, y: 20}) // curried version
`

isAction

A utility function that detects if the object is of Action type.

`ts
import {isAction} from 'action-type'

isAction({}) // returns false
isAction(action('WWW', null)) // returns true
`

Nil

A default action that represents nothingness.

`ts
import {Nil} from 'action-type'

function logic(a: number) {
if (a > 10) return action('greater', a - 10)
if (a < 10) return action('lesser', 10 - a)
return Nil
}
`

List

A utility function that creates an Action from a list of Action[].

`ts
import {List} from 'action-type'

const list = List(action('A', 1), action('B', 2))
`

isList

A utility function that checks if the action is of list type

`ts
import {isList} from 'action-type'

const list = List(action('A', 1), action('B', 2))

isList(list) //true
`

isNil

A utility function that checks if the action is of Nil

`ts
import {isNil, Nil} from 'action-type'

isNil(Nil) // true
isNil({type: '@@NIL', value: {}}) // true
isNil({type: 'click', value: {}}) // false
``