stateless.js

const createDispatch = (state, doThingsWithUpdatedState) => {
  return (executeChange) => {
    const newState = executeChange(state)
    return doThingsWithUpdatedState(newState, createDispatch(newState, doThingsWithUpdatedState))
  }
}

const initialState = { counter: 0 }

const dispatch = createDispatch(initialState, (newState, dispatch) => {
  document.write(newState.counter)

  setTimeout(() => {
    dispatch(({ counter }) => ({ counter: ++counter }))
  }, 1000)
})


// start it!
dispatch(state => state)