title: NSPredicate Regex error
body: <p>I'm dealing with a document management page. I used <code>NSPredicate</code> regular expression while got the <code>searchBar.text</code> from user inputs. An error occurred (as the image below) while the inputs are brackets in Chinese form but went well in English form. If anyone has come across this matter? Thank you.<br>
  <img src="https://i.stack.imgur.com/4wPH5.jpg" alt="enter image description here"></p>
  
  <p>Here is my code,crash happen to the last row.</p>
  
  <pre><code>NSString * searchStr = [NSString stringWithFormat:@"fileName like[cd] \'*%@*\'",searchDisplayController.searchBar.text];
  NSPredicate *predicate = [NSPredicate predicateWithFormat:searchStr];
  self.fileArrayAfterPre =  [[NSMutableArray alloc] initWithArray:[fileArr filteredArrayUsingPredicate:predicate]];
  </code></pre>