define xxlist
  xgetptr $
  set $cons = (struct Lisp_Cons *) $ptr
  xgetptr Qnil
  set $nil = $ptr
  set $i = 0
  while $cons != $nil && $i < 20
    set $car = $cons->u.s.car
    # xgettype $car
    # if $type == Lisp_Cons
    #   printf "(cons "
    #   set $consptr = $ptr
    #   xgetptr $car
    #   set $car_ptr = (struct Lisp_Cons *) $ptr
    #   xpp $car_ptr->u.s.car
    #   xgettype $car_ptr->u.s.u.cdr
    #   if $type == Lisp_Cons
    #     printf "..."
    #   end
    #   set $ptr = $consptr
    #   printf ")"
    # else
      xpp $car
    # end

    xgetptr $cons->u.s.u.cdr
    set $cons = (struct Lisp_Cons *) $ptr
    set $i = $i + 1
    printf "\n"
  end
  if $cons == $nil
    printf "nil\n"
  else
    printf "...\n"
    p $ptr
  end
end

define xpp
  xgettype $arg0
  if $type != Lisp_Misc
    output $type
    printf ":"
  end
  if $type == Lisp_String
    xgetptr $arg0
    set $caar_str = (struct Lisp_String *) $ptr
    xprintstr $caar_str
  end
  if $type == Lisp_Misc
    xgetptr $arg0
    output (enum Lisp_Misc_Type) (((struct Lisp_Free *) $ptr)->type)
  end
  if $type == Lisp_Int0 || $type == Lisp_Int1
    xgetint $arg0
    output $int
  end
  if $type == Lisp_Symbol
    xsymname $arg0
    xgetptr $symname
    set $caar_symname = (struct Lisp_String *) $ptr
    xprintstr $caar_symname
  end
  if $type == Lisp_Cons
    printf "("
    xgetptr $arg0
    set $xpp_cons = (struct Lisp_Cons *) $ptr
    while $xpp_cons != $nil
      set $xpp_car = $xpp_cons->u.s.car
      # this will likely fail for nested lists.
      xpp $xpp_car
      printf " "

      set $xpp_cdr = $xpp_cons->u.s.u.cdr
      xgettype $xpp_cdr
      if $type == Lisp_Cons
        xgetptr $xpp_cdr
        set $xpp_cons = (struct Lisp_Cons *) $ptr
      else
        printf ". "
        xpp $xpp_cdr
        loop_break
      end
    end
    printf ")"
  end
end