redux

const createStore = (reducer) =>
{
        let state;
        let listeners = [];

        const getState = () => state;

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


        const subscribe = (listener) =>
        {
            listeners.push(listener);
            console.log(listeners);
            return () =>
            {
                listeners = listeners.filter((cb) =>
                {
                    return cb != listener;
                });
            }
        };

        //initial state
        dispatch({});

        return {getState , dispatch, subscribe};
};