title: expat function XML_StartElementHandler - how to work with it?
body: <p>I'm writing xml parser using expat . 
  just saw this :</p>
  
  <pre><code>XML_SetElementHandler
       XML_Parser parser,
       XML_StartElementHandler start,
       XML_EndElementHandler end
  </code></pre>
  
  <p>I don't understand what should it do
  I see that it's a pointer to a function :</p>
  
  <pre><code>typedef void (*XML_StartElementHandler)(void *userData,
                      const XML_Char *name,
                      const XML_Char **atts);
  </code></pre>
  
  <p>but I can't find anywhere what should it do 
  would love to get some help!</p>