Calling a record type's methods (functions or procedure) when record is in an array

[Mace Ayres <maceayres0@gmail.com>]

My package 'trunks.ads' includes 
...
type a_trunk;.

function set_lock ...  return lock_state;

function post_val(v:integer) --- return integer
...
type a_trunk is
  record
     id : ,,,
    val
    ...
    lock  : lock_state    -- enumeration type defined earlier (open, locked)
  end record;

Package body 'trunks.adb  includes ...

function set_lock (  ..... not relevant

function post_val i(v:integer)  return integer is ..return v;

------
In package 1 I have a multi dimension array of type a_truck that I get to with
..
loop de loop i,j
my_trunk_array (i)(j)
..
-------

To modify the item val in the trunk at array (5)(3) I code..

... my_truck_arrary(5)(3).val := trunks.post_val(N)

rather than my_tunk_arrary(5)(3).val := N

so I don't directly access the a_trunk record's value fields directly

-- I have to add the private part too, to hide the inners of type a_trunk.

It seem a little convoluted, but I see no other way to manipulate my a_truck type records that only 'exist' the array.

I am just learning Ada. Is this reasonable?