Re: When is a rename not a rename?

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Fri, 1 Feb 2013 02:44:21 -0800 (PST), Ada novice wrote:

> If you have a minimal example that is proving the contrary, please post it here.

Here is how renaming is not renaming:

with Ada.IO_Exceptions;
procedure Test is
   package P is
      End_Error : exception renames Ada.IO_Exceptions.End_Error;
   end P;
   use P, Ada.IO_Exceptions;
begin
   null;
exception
   when End_Error => -- Compile error, should be none
      null;
end Test;

This is "diamond diagram" constructed using renaming:

procedure Test is
   package P is
      I : Integer;
   end P;
   package Q is
      J : Integer renames P.I;
   end Q;
   package R is
      J : Integer renames P.I;
   end R;
   use Q, R;
   X : Integer := J; -- Compile error, should be none
begin
   null;
end Test;

[Diamond diagram is common-place bogus argument against MI]

Yet another example when rename is something totally broken:

with Ada.Text_IO; use Ada.Text_IO;
procedure Test is
   X : Integer;
   Y : Positive renames X;
begin
   Y := -1;
   Put_Line ("And today positive number is " & Integer'Image (Y));
end Test;

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de