Push based state change propagation

push-based.js

/*
 *  Each property has getters and setters with subscribers
 */
let subscribers = new Set()
let activeJob = null

let a = 3

const state = {
  get a () {
    subscribers.add(activeJob)
    return a
  },
  set a (newValue) {
    a = newValue
    subscribers.forEach(job = job())
  }
}

/*
 *  Autorun functions takes the update function and turns it into a job
 */
const autorun = update => {
  function job () {
    activeJob = job
    update()
    activeJob = null
  }
  job()
}

/*
 *  View updates are basically a job triggered by state changes
 */
autorun(() => {
  view = render(state)
})