title: NSPredicate on array of arrays
body: <p>I have an array, that when printed out looks like this:</p>
  
  <pre>
  (
          (
          databaseVersion,
          13
      ),
          (
          lockedSetId,
          100
      )
  )
  </pre>
  
  <p>Would it be possible to filter this using an <code>NSPredicate</code> (potentially by the index in the array). So something like: give me all rows where element 0 is 'databaseVersion'? I know that if I had an array of dictionaries I could do this with a predicate similar the one found <a href="https://stackoverflow.com/questions/2506836/nspredicate-and-arrays">here</a>, but I found that when using dictionaries and storing a large amount of data, my memory consumption went up (from ~80mb to ~120mb), so if possible I would to keep the array. Any suggestions on how this might be done?</p>