Re: terminate applications

["Nick Roberts" <nickroberts@blueyonder.co.uk>]

"Riccardo" <rfulcoli@amsjv.it> wrote in message
news:bf5uks$8n0$1@e3k.asi.ansaldo.it...

> is present a function that terminated applications?
> if yes what's?
>
> for example: exit(0); // language C

You should transfer control to the end of the main subprogram. For example:

   with Ada.Text_IO;
   procedure Main is
      Count: Natural := 0;
      procedure Some_Inner_Procedure is
         use Ada.Text_IO;
      begin
         Put_Line("Hello World");
         if Count = 100 then
            -- we want to terminate program here
            goto End_of_Program;
         end if;
      end Some_Inner_Procedure;
   begin
      loop
         Some_Inner_Procedure;
         Count := Count + 1;
      end loop; -- infinite loop
   <<End_of_Program>> -- this is how you write a goto label in Ada
   end Main;

This example doesn't necessarily show the most elegant technique, but it is
generally acceptable, and illustrates the idea.

Of course, the best technique is always to let the program flow naturally to
the end of the main subprogram, if it is reasonable to do so. To illustrate
this, the above example would certainly be better rewritten like this:

   with Ada.Text_IO;
   procedure Main is
      procedure Some_Inner_Procedure is
         use Ada.Text_IO;
      begin
         Put_Line("Hello World");
      end Some_Inner_Procedure;
   begin
      for i in 1..100 loop
         Some_Inner_Procedure;
      end loop;
   end Main;

I think it is quite important that, normally, you do not use any other
method to terminate an Ada program, since using another method could prevent
library packages (e.g. Ada.Text_IO, used in my examples) from finalizing
('cleaning up') properly.

PS: Would the above be suitable for submission to OSnippets in the Ada
category?

--
Nick Roberts
Jabber: debater@charente.de [ICQ: 159718630]