title: UITextPosition to NSRange
body: <p>I need to use NSStringFromRange but I only have a start and end UITextPositions. How do you convert UITextPosition to NSRange.</p>
  
  <pre><code>NSMutableArray * wordArray = [[NSMutableArray alloc]init];
  id&lt;UITextInputTokenizer&gt; tokenizer = tv.tokenizer;
  UITextPosition *start = tv.beginningOfDocument;
  while (![start isEqual:tv.endOfDocument]) {
      UITextPosition *end = [tokenizer positionFromPosition:start toBoundary:UITextGranularityWord inDirection:UITextStorageDirectionForward];
      NSString *word = [tv textInRange:[tv textRangeFromPosition:start toPosition:end]];
      [wordArray addObject:NSStringFromRange(&lt;#NSRange range#&gt;)];
      start = end;
  }
  </code></pre>