title: How to use the first character as a section name
body: <p>I'm using Core Data for a table view, and I'd like to use the first letter of each of my results as the section header (so I can get the section index on the side). Is there a way to do this with the key path? Something like below, where I use <code>name.firstLetter</code> as the <code>sectionNameKeyPath</code> (unfortunately that doesn't work).</p>
  
  <p>Do I have to grab the first letter of each result manually and create my sections like that? Is it better to put in a new property to just hold the first letter and use that as the <code>sectionNameKeyPath</code>?</p>
  
  <pre><code>NSFetchedResultsController *aFetchedResultsController = 
  [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest
              managedObjectContext:managedObjectContext
              sectionNameKeyPath:@"name.firstLetter"
              cacheName:@"Root"];
  </code></pre>
  
  <p>Thanks.</p>
  
  <p>**EDIT: ** I'm not sure if it makes a difference, but my results are Japanese, sorted by Katakana. I want to use these Katakana as the section index.</p>