$a = {
 bla => 1,
 trax => [ #comment
 bla2 => { #comment
 sauh1 => 1666,
 3 => 2,
 },
 ],

 bla => 1,
 _periods => 2
};

my $h_periodsxxxxxxxxx = {
 Mercury => { orbital => 0.24, rotation => 58.64 },
 Venus => { orbal => 0.62, rotation => -243.02 },
 Earth => { orbital => 1.00, rotation => 1.00 },
 Mars => { orbital => 1.88, rotation => 1.03 },
 Jupiter => { orbital => 11.86, rotation => 0.41 },
 Saturn => { orbital => 29.46, rotation => 0.43 },
 Uranus => { orbital => 84.01, rotation => -0.72 },
 Neptune => { orbital => 164.8, rotation => 0.67 },
};

__END__
(lisp-mode)

(defun end-perl ()
  "Return position of last Perl character in Buffer"
  (save-excursion
    (beginning-of-buffer)  
    (search-forward "\n__END__")
    (point)
    )
  )


(progn
  ;; activate Perl mode
  (cperl-mode)
  ;; reset example code
  (replace-regexp "\\s-+" " " nil 0 (end-perl))         
  ;; indent perl code
  (indent-region 0 (end-perl))

  ;; align fat commas
  (align
   0                            ; BEG
   (end-perl)                   ; END

   ;; SEPARATE on starting ]} or ending {[
   "\\(^\\s-*$\\|^\\s-*[]}]\\|[[{]\\s-*\\(#\\|$\\)\\)"        

   ;; RULE
   '(
     (perl-hash-pair
      (regexp   . "\\(\\s-*\\)=>\\(\\s-*\\)")
      (group    . (1))
      (modes    . align-perl-modes)
      (tab-stop . nil)
      (repeat  . t)
      (justify . t)
      )
     )
   )
  ;; reactivate lisp mode for experimenting
  (lisp-mode)
  )