referencing columns

[Douglas Surber]

Slice is useful when a subsequence of columns form a larger concept, especially when that subsequence is used multiple times, eg address. A query could return mailing address and shipping address.

  mailingAddress = readAddress(col.at <http://col.at/>(“mailing_address”).slice(5));
  shippingAddress = readAddress(col.at <http://col.at/>(“shipping_address).slice(5));

public Address readAddress(Column col) {
  return new Address(col.get(String.class), // street 1
                                   col.next().get(String.class), // street 2
                                   col.next().get(String.class), // city
                                   col.next().get(String.class), // state
                                   col.next().get(String.class)); // postal code

Using slice isolates the caller from the motion done by the subroutine. It also allows the method to use forEach and other iterator methods.

Douglas
  

> On May 7, 2018, at 4:28 AM, Vladimir Sitnikov <sitnikov.vladimir at gmail.com> wrote:
> 
> I agree, slice method looks odd.
>