are there iterators and loops in puppet?

Question

When I define(?) a resource e.g. to ensure dir structure, are there any loops available?

Like that:

  for X in [app1,app2] do:
    file { '/opt/app/' + X:
      ensure => directory,
      owner  => 'root',
      group  => 'root',
      mode   => '0644',
    }

I have tens of directories and I am really tired with declaring it in puppet.. It would take 15 LOC of bash.

Any ideas?