Code review comment for lp:~zorba-coders/zorba/concat_operator

A small code improvement: rather thah doing a dynamic_cast to check if an expr is an fo_expr, use the get_expr_kind() method. So, the code would look like this:

if (right->get_expr_kind() == fo_expr_kind)
{
  fo_expr* lfoExpr = static_cast<fo_expr*>(right.getp());
  etc....;
}

Also, please respect the coding style of the files you update. In this case, put the "{" in a separate line.