Classes Are Making Me Sad(gist.github.com)

    typeof (class {}) === "function"

   // provided by some view library
   let Component = {
     state: null,

     setState(state) {
       Object.assign(this.state, state);
       this.forceUpdate(); 
     }

     // ...
   }

   let Counter is Component {
     get state() {
       return { count: 0 };
     },

     inc() {
       let { count } = this.state;
       let { step } = this.props;
       this.setState({ count: count + step });
     },

     render() {
       let { count } = this.state;
       return <button
     }
   }

   render(<Counter step={2} />);

   // let Counter is Component
   let Counter = Object.create(Component);