Manipulate called controller function name before it is called?

[eluser]dudeami0[/eluser]

Code:

class Foo extends Controller {
  
   function bar() {
      if ($this->input->post('form') !== false) {
         $this->bar_post();
      } else {
         // Form here?
      }
   }

   function bar_post() {
      // Post stuff here
   }

}

That would work :p