Re: Ada requires too much typing!

[Georg Bauhaus <rm.dash-bauhaus@futureapps.de>]

On 08.06.10 12:10, Niklas Holsti wrote:
> Martin Krischik wrote:
> 
>> just about as painful as using local packages to add static variables
>> to Ada procedures.
> 
> Later Martin Krischik wrote:
> 
>> function f returns Integer
>>
>>   package i is
>>     g : Integer := 0;
>>   end i;
>>
>> begin
>>   i.g := i.g + 1;
>>   return i.g;
>> end f;
> 
> If you mean the latter code to be an example of the former task (add
> static variable), I believe you are mistaken.

I thought, too, that a new variable decl inside the local package
would still be elaborated each time. The initilization of g
confirms when tested.

But then I thought, surprise!, doubted everything I thought
I had learned about Ada. Looking at this:

with Ada.Text_IO;  use Ada.Text_IO;

procedure Sttc is

   type T is range 0 .. 10;

   procedure A is
      package P is  -- local package
         V: T;    -- presumably static?
      end P;
   begin
      if P.V'Valid then
         P.V := P.V + 1;
      else
         P.V := T'First;
      end if;
      Put_Line (T'Image(P.V));
   end A;

begin
   A; A; A;
end Sttc;


$ ./sttc
 0
 1
 2
 3
$

Compiled with or without -gnatVa.  But this seems to be accidental,
V is just a variable that isn't initialized, living on the stack.
Confirmation:

with Ada.Text_IO;  use Ada.Text_IO;

procedure Sttc is

   type T is range 0 .. 10;

   procedure A is
      package P is
         V: T;
      end P;
   begin
      if P.V'Valid then
         P.V := P.V + 1;
      else
         P.V := T'First;
      end if;
      Put_Line (T'Image(P.V));
   end A;

   procedure Ovrwrt_Stk  is
      X : T;
   begin
      X := T'First;
   end Ovrwrt_Stk;

begin
   A; Ovrwrt_Stk; A; Ovrwrt_Stk; A; Ovrwrt_Stk; A;
end Sttc;

$ ./sttc
 0
 1
 1
 1
$

Phew. Back to normal.