title: es6: How to define functions inside a const?
body: <p>I'm doing this react-native project and i am using <a href="https://medium.com/the-react-native-log/organizing-a-react-native-project-9514dfadaa0#.u7ggwk3uq" rel="noreferrer">this method</a> to organize my project files but i don't know how to declare functions inside a const.</p>
  
  <pre><code>import React from 'react';
  import { View, ListView, Text } from 'react-native';
  
  const Category = (props) =&gt; {
  
      const ds = ListView.DataSource({rowHasChanged : (r1, r2) =&gt; r1 !== r2});
  
      // how to declare function here?
  
      return (
          &lt;View&gt;
              &lt;ListView
                  dataSource={ds}
                  renderRow={(rowData) =&gt; &lt;Text&gt;{rowData}&lt;/Text&gt;}
                  renderSeparator={// how to put function reference here?}
              /&gt;
          &lt;/View&gt;
      );
  }
  </code></pre>