title: split NSString using componentsSeparatedByString
body: <p>I have a string I need to split. It would be easy using componentsSeparatedByString but my problem is that the separator is a comma but I could have commas that aren't separator.</p>
  
  <p>I explain:</p>
  
  <p>My string:</p>
  
  <pre><code>NSString *str = @"black,red, blue,yellow";
  </code></pre>
  
  <p>the comma between red and blue must not be considered as separator.</p>
  
  <p>I can determine if comma is a separator or not checking if after it there is a white space.</p>
  
  <p>The goal is to obtain an array with:</p>
  
  <pre><code>(
  black,
  "red, blue",
  yellow
  )
  </code></pre>