pull-based state change propagation

pull-based.js

/*
 *  State change mechanism
 */
let update

const onStateChange = _update => {
    update = _update
}

const setState = newState => {
    state = newState
    
    update()
}

/*
 *  Change is propagated to the view when state has changed
 */
onStateChange(() => {
    view = render(state)
})