CVS difference for ai12s/ai12-0005-1.txt

--- ai12s/ai12-0005-1.txt	2019/11/08 04:28:19	1.31
+++ ai12s/ai12-0005-1.txt	2019/11/15 05:18:40	1.32
@@ -1640,7 +1640,147 @@
 
 ***************************************************************
 
-Editor's note (October 28, 2019): All of the items above this
+From: Pascal Pignard
+Sent: Tuesday, October 15, 2019  2:18 PM
+
+[From private mail.]
+
+I've read the AARM 202x draft 22 (text version).
+
+Section 7.3 Private Types and Private Extensions, I've found:
+7.w/2              procedure Bar (X : T1'Class) is
+                   begin
+                      Pkg.Foo (X); -- should call Foo #1 or an override thereof
+                   end;
+
+GNAT complains with: error: expected type "Ifc"
+
+I propose the change:
+         Pkg.Foo (Pkg.Ifc'Class(X)); -- should call Foo #1 or an override thereof
+
+It compiles but I when I execute:
+7.x/2           begin
+                   Pkg.Foo (Pkg.Ifc'Class (P_Client.X));      -- should call Foo #2
+                   Bar (T1'Class (P_Client.X));
+                end P;
+I got:
+Foo #2
+Foo #2
+
+Is it correct?
+
+In order to get Foo #1, I execute:
+      X:T1;
+   begin
+      Pkg.Foo (Pkg.Ifc'Class(X));
+      Bar (X);
+   end P;
+==
+Foo #1
+Foo #1
+
+
+PS: I make a little change in the AARM example to avoid illegal statement.
+See full source code:
+
+with Ada.Text_IO;
+procedure Test40 is
+
+-- Section_7_3_Paragraph_7q
+
+   package P is
+      package Pkg is
+         type Ifc is interface;
+         procedure Foo (X : Ifc) is abstract;
+      end Pkg;
+
+      type Parent_1 is tagged null record;
+
+      --  type T1 is new Parent_1 with private;
+      type T1 is new Parent_1 and Pkg.Ifc with private; --@@ Change to avoid further illegal type declaration
+   private
+      type Parent_2 is new Parent_1 and Pkg.Ifc with null record;
+      procedure Foo (X : Parent_2); -- Foo #1
+
+      --                type T1 is new Parent_2 with null record; -- Illegal.
+      type T1 is new Parent_2 with null record;
+   end P;
+
+      --@      with P;
+   package P_Client is
+      type T2 is new P.T1 and P.Pkg.Ifc with null record;
+      procedure Foo (X : T2); -- Foo #2
+      X : T2;
+   end P_Client;
+
+   package body P_Client is
+      procedure Foo (X : T2) is
+      begin
+         Ada.Text_IO.Put_Line ("Foo #2");
+      end Foo; -- Foo #2
+   end P_Client;
+
+      --@     with P_Client;
+   package body P is
+         --@        ...
+      procedure Foo (X : Parent_2) is
+      begin
+         Ada.Text_IO.Put_Line ("Foo #1");
+      end Foo; -- Foo #1
+
+      procedure Bar (X : T1'Class) is
+      begin
+         Pkg.Foo (Pkg.Ifc'Class (X)); -- should call Foo #1 or an override thereof
+      end Bar;
+
+      X : T1;
+
+   begin
+      Pkg.Foo (Pkg.Ifc'Class (P_Client.X));      -- should call Foo #2
+      Bar (T1'Class (P_Client.X));
+      Pkg.Foo (Pkg.Ifc'Class (X));
+      Bar (X);
+   end P;
+
+begin
+   null;
+end Test40;
+
+***************************************************************
+
+From: Randy Brukardt
+Sent: Thursday, November 14, 2019  9:29 PM
+
+Eliminating the illegal line eliminates the point of the example, so I don't 
+think it is particularly relevant what the rest of it does, or what it 
+executes if it is modified to be legal.
+
+> I propose the change:
+>          Pkg.Foo (Pkg.Ifc'Class(X)); -- should call Foo #1 or an 
+> override thereof
+
+I worry this would be confusing for this example, but it can't be helped.
+Part of the point is that identical calls could have different results 
+depending on visibility, and I suppose this change makes it even more obvious. 
+
+> It compiles but I when I execute:
+> 7.x/2           begin
+>                    Pkg.Foo (Pkg.Ifc'Class (P_Client.X));      
+> -- should call Foo #2
+>                    Bar (T1'Class (P_Client.X));
+>                 end P;
+> I got:
+> Foo #2
+> Foo #2
+> 
+> Is it correct?
+
+Yes, once you make the interface visible, normal overriding occurs. This isn't 
+very interesting.
+
+***************************************************************
+
+Editor's note (November 14, 2019): All of the items above this
 marker have been included in the working version of the AARM.
 
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