# CommonEdge Interview with Jarrett

## Smidgeon of Typescript

const f = <A,B>(x: A): B => /* ... */;
const g = <B,C>(y: B): C => /* ... */;
const h = <A,C>(x: A): C => g(f(x));

const ListView = <T>(items: T[]) => new React.Element(...);

const { data: gpsCoords, isLoading } = useGpsPoints();
const { data: } = useUser();

## React References

## State Handling Preferences

Started out with lots of context, moved to prop drilling.

Kent C Dodds

// create context

// default object

// build your reducer

// exported context provider
// reducer function and state

// export useContext query

// function
setThis()
setThat()
setReset()

// event
dispatch({
    type: 'EVENT'
})
interface NumEditProps {
    currentValue: number;
    update: (x: number): void;
}
const NumberEditor = (ps: NumEditProps) => {

}

const handle = (x: numbmer) => state.set(x => x+=num);

handle === handle; // true

handle !== (x: numbmer) => state.set(x => x+=num); // false
                                        

<NumberEditor currentValue={3} update={handle}></NumberEditor>