original_string: public function traverse(callable $callable)
      {
          foreach ($this->_conditions as $c) {
              if ($c instanceof ExpressionInterface) {
                  $callable($c);
                  $c->traverse($callable);
              }
          }
      }
code: public function traverse(callable $callable)
      {
          foreach ($this->_conditions as $c) {
              if ($c instanceof ExpressionInterface) {
                  $callable($c);
                  $c->traverse($callable);
              }
          }
      }
code_tokens: public function traverse ( callable $ callable ) { foreach ( $ this -> _conditions as $ c ) { if ( $ c instanceof ExpressionInterface ) { $ callable ( $ c ) ; $ c -> traverse ( $ callable ) ; } } }
docstring: Traverses the tree structure of this query expression by executing a callback
  function for each of the conditions that are included in this object.
  Useful for compiling the final expression, or doing
  introspection in the structure.
  
  Callback function receives as only argument an instance of ExpressionInterface
  
  @param callable $callable The callable to apply to all sub-expressions.
  @return void
docstring_tokens: Traverses the tree structure of this query expression by executing a callback function for each of the conditions that are included in this object . Useful for compiling the final expression or doing introspection in the structure .