Q: Localizing type and package references

[b.mcguinness747@gmail.com]

I want to write an Ada program using the Wide_Character type, but I might
want to move to Wide_Wide_Character later on.  So I want to localize all
references to Wide_Character and the associated standard Ada packages to
a single file that I can easily update.  If I was working in C++, I would
use typedefs to create pseudonyms and put these in a header file that I could
#include from various source files.  So I have tried to do something similar
in Ada.  I created the file types.ads:

--------------------------------------------------------------------------------
-- Types - Declarations of data types and related packages
--------------------------------------------------------------------------------
with Ada.Characters;
with Ada.Characters.Wide_Latin_1;
with Ada.Strings;
with Ada.Strings.Wide_Maps;
with Ada.Strings.Wide_Unbounded;
with Ada.Wide_Characters;
with Ada.Wide_Characters.Handling;
with Ada.Wide_Text_IO;
with Ada.Wide_Text_IO.Text_Streams;

package Types is
  package Chars         renames Ada.Characters.Wide_Latin_1;
  package Char_Handling renames Ada.Wide_Characters.Handling;
  package Char_IO       renames Ada.Wide_Text_IO;
  package Char_Maps     renames Ada.Strings.Wide_Maps;
  package Char_Streams  renames Ada.Wide_Text_IO.Text_Streams;
  package Char_Strings  renames Ada.Strings.Wide_Unbounded;

  subtype Char        is Wide_Character;
  subtype Char_String is Ada.Strings.Wide_Unbounded.Unbounded_Wide_String;
end Types;


and then tried referencing this from the main program file with:


with Types;
use  Types;

with Char_Strings;


but the compiler (Gnat 4.6) complains that there is no file called
char_strings.ads.  I am not sure if I have made a simple mistake that
can be easily corrected to make this work, or if there is a different
approach that I should be trying.

Help would be appreciated.

Thanks.

--- Brian