dispatcher.js

const action = {
  type, // specify the action type
  data // optional data can be passed
};

Store.prototype.dispatch = function(action) {
  // based on the action type
  // generate a new state of the application,
  // by passing it to a reducer
  const state = this.reducer(action);
  this.state = state;
  // Brodcast the new state to all subscribers
};