GlobalState.re

Home.re

let component = ReasonReact.statelessComponent("Home");

let make = _children => {
  ...component,
  render: _self =>
    <div className=Style.container>
      <Store>
        ...(
             ({state, send}) =>
               <div>
                 <h1> (ReasonReact.stringToElement(state.text)) </h1>
                 <button onClick=(_e => send(Store.ChangeWorld))>
                   (ReasonReact.stringToElement("change"))
                 </button>
               </div>
           )
      </Store>
    </div>
};

Store.re

type action =
  | ChangeWorld;
type state = {text: string};
let initialState = () => {text: "world"};
let reducer = (action, state) =>
  switch action {
  | ChangeWorld =>
    ReasonReact.Update(
      state.text === "world" ? {text: "hello"} : {text: "world"}
    )
  };
let component = ReasonReact.reducerComponent("Store");
let make = children => {
  ...component,
  initialState,
  reducer,
  render: self => children(self)
};