park-brian/index.html

## index.html
<!DOCTYPE html>
<html>

<head>
  <script>
    window.state = {counter: 0};
    const listeners = [];

    const reducer = (state, action) => ({
      INC: {...state, counter: state.counter + 1},
      DEC: {...state, counter: state.counter - 1},
    }[action.type] || state);

    const dispatch = (action) => {
      window.state = reducer(window.state, action);
      listeners.forEach(listener => listener());
    }

    const subscribe = (callback) => listeners.push(callback);

    const render = () => document.getElementById('counter').innerText = window.state.counter;

    subscribe(render);
  </script>

</head>

<body>
  <span id="counter">0</span>
  <button onclick="dispatch({type: 'INC'})">+</button>
  <button onclick="dispatch({type: 'DEC'})">-</button>
</body>

</html>
	<!DOCTYPE html>
	<html>

	<head>
	<script>
	window.state = {counter: 0};
	const listeners = [];

	const reducer = (state, action) => ({
	INC: {...state, counter: state.counter + 1},
	DEC: {...state, counter: state.counter - 1},
	}[action.type] \|\| state);

	const dispatch = (action) => {
	window.state = reducer(window.state, action);
	listeners.forEach(listener => listener());
	}

	const subscribe = (callback) => listeners.push(callback);

	const render = () => document.getElementById('counter').innerText = window.state.counter;

	subscribe(render);
	</script>

	</head>

	<body>
	<span id="counter">0</span>
	<button onclick="dispatch({type: 'INC'})">+</button>
	<button onclick="dispatch({type: 'DEC'})">-</button>
	</body>

	</html>