ReasonML: getting started - actions, reducers, and initialState

app.re

type state = {
  weather: WeatherData.weather
};

type action =
  | WeatherLoaded(WeatherData.weather);

let component = ReasonReact.reducerComponent("App");

let dummyWeather: WeatherData.weather = {
  summary: "Warm throughout the day",
  temp: 30.5
};

let make = (_children) => {
  ...component,

  initialState: () => {
    weather: dummyWeather
  },

  reducer: (action, _prevState) => {
    switch action {
    | WeatherLoaded(newWeather) =>
      ReasonReact.Update({
        weather: newWeather
      })
    }
  },

  render: (self) =>
    <div className="App">
      <p> (ReasonReact.stringToElement(self.state.weather.summary)) </p>
    </div>
};