title: React way to "setState" in a pure ES2015 function
body: <p>React newb here.  I have a pure function that returns a form (presentation component).  In this form I need to handle onChange events for those text fields that are controlled.  FWIU, I need to this.setState(...) in my onChange event handlers.  However due to this being a pure function, I don't have access to this.setState().  Is there a nice way to set the state on these onChange events in a ES2015 function?  I'm also using redux if this helps.  Example code:</p>
  
  <pre><code>import React, {PropTypes} from 'react'
  
  const ApplicationForm = ({submitHandler, person}) =&gt; (
  &lt;form onSubmit={e =&gt; submitHandler(e)}&gt;
   &lt;div&gt;
              &lt;label htmlFor="firstName"&gt;First Name:&lt;/label&gt;
              &lt;input type="text" name="firstName" onChange={e =&gt; setState(e.target.value)} value={person.firstName || ''}/&gt;
   &lt;/div&gt;
  ...
  &lt;/form&gt;
  )
  </code></pre>