title: Using React's immutable helper with Immutable.js
body: <p>I'm working on a flux application and am considering adopting <a href="https://github.com/facebook/immutable-js">immutable.js</a> to maintain state.  I saw that react supplies its own helper for updating immutable objects (<a href="http://facebook.github.io/react/docs/update.html">http://facebook.github.io/react/docs/update.html</a>), but couldn't tell how it was much different from immutable's own setIn and updateIn methods (i.e, i can already compare objects with === to se if they changes with setIn).  Is there a reason to use the react helper with immutable.js?  Is it just syntactic sugar?</p>
  
  <p>TL;DR is:</p>
  
  <pre><code>var map = Immutable.fromJS({bar: 'baz'});
  map2 = React.addons.update(map, {
          bar: {$set: 'foo'}
      });
  </code></pre>
  
  <p>different from</p>
  
  <pre><code>var map = Immutable.fromJS({bar: 'baz'});
  map2 = map.set('bar', 'foo');
  </code></pre>