RestaurantFinder

RestaurantFinder.kt

fun restaurantsNearUser(): Flow<List<Restaurant>> =   
    flow {
        emit(null)
        gpsService.currentUserLocation().also { location ->
            emit(location)
        }
    }
    .map { userLocation ->
        buildRestaurantList(userLocation)
    }
    .distinctUntilChanged() // we won't notify observers if the list hasn't changed
    .flowOn(Dispatchers.Default) // All sorting work will be done in a non-UI Thread
    
// Here, we can build the restaurant list from our Restaurant data
// For example, if userLocation is null, then the list is unsorted
// If userLocation is non-null, then we can sort the list so that closer restaurants appear on top
fun buildRestaurantList(userLocation: GPSCoordinates?): List<Restaurant> {
    // ...
}