asyncmachine

Hybrid State Machine

Usage no npm install needed!

<script type="module">
  import asyncmachine from 'https://cdn.skypack.dev/asyncmachine';
</script>

README

AsyncMachine is a relational state machine made for declarative flow control. It supports multiple states simultaneously, executes methods based on a dependency graph and provides an event emitter.

It allows for easy:

  • state management
  • parallel tasks
  • loose coupling
  • resource allocation / disposal
  • exception handling
  • fault tolerance
  • method cancellation

It supports forming a network of state machines and can also be used as a simple state management library. Gzipped code is 7.5kb.

Install

npm i asyncmachine

Documentation

Components:

  • states
  • transitions
  • relations
  • clocks
  • pipes
  • queues

Features:

Examples

Dry Wet

This basic examples makes use of: states, transitions, relations and synchronous mutations.

import { machine } from 'asyncmachine'
// define
const state = {
  Wet: { require: ['Water'] },
  Dry: { drop: ['Wet'] },
  Water: { add: ['Wet'], drop: ['Dry'] }
}
// initialize
const example = machine(state)
// make changes
example.add('Dry')
example.add('Water')
// check the state
example.is() // -> [ 'Wet', 'Water' ]

example

Negotiation

Presents how the state negotiation works.

Async Dialog

Presents the following concepts: automatic states, synchronous mutations, delayed mutations and loose coupling.

Exception State

A simple fault tolerance (retrying) using the Exception state.

Piping

Shows how pipes forward states between machines.

Transitions

Shows various types of transition handlers and the way params get passed to them.

TodoMVC and React

Classic TodoMCV example using AsyncMachine as the controller and React as the view.

State streams with RxJS

Observe state changes and navigate through specific paths with RxJS, then feed the result back as a state.

  • Comming soon!

Restaurant

A complex example showing how to solve the producer / consumer problem using AsyncMachine.

inspector view

GTD Bot

For a real world example check GTD Bot - a sync engine for Google APIs.

Preview

Use cases

  • state management
  • synchronizing async actions
  • solving non-linear problems
  • fault tolerance
  • resource allocation / disposal
  • avoiding race conditions
  • thread pools
  • sync engines

License

MIT