Function to update addresses and add lat long in Swift

In an OS X Swift 3 app I have a function that reads in a data file on location names and addresses. About 2000 items. I'd like to run through the list, call let geocoder = CLGeocoder() [login to view URL](address, completionHandler: {(placemarks, error) and add the returned location (address and lat long) to each entry in the original list. Below is my current code. I'm not sure how to handle getting the returned values back to the original list and also handling that I there are some limits on how often I can call this function. let locations = ReadCSV() let address = locations[1].MailAddr1 + ", " + locations[1].MailCity + ", " + locations[1].MailState + ", " + locations[1].MailZip + ", " + locations[1].MailCountry let geocoder = CLGeocoder() [login to view URL](address, completionHandler: {(placemarks, error) -> Void in if((error) != nil){ print("Error", error) } if let placemark: CLPlacemark = placemarks?.first { let name = [login to view URL] let address = [login to view URL] let locality = [login to view URL] let zip = [login to view URL] let subLocality = [login to view URL] let country = [login to view URL] let coordinates:CLLocationCoordinate2D = [login to view URL]!.coordinate let locataion: CLLocation = [login to view URL]! } })