I don't remember much of Ada, but here's something very basic I liked (had to look the details up):

You could declare custom integer types like this:

type My_Type is range -5 .. 10;

And then you could reference the range with My_Type'First or My_Type'Last

And there were named parameters.

   for A in Range_Type loop
      I_IO.Put (
         Item  => A,
         Width => 3,
         Base  => 10);
      ...
   end loop;