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adaada2012

How to stop execution in my program


Without copy-pasting my code here, how can I stop my ADA program from executing anymore lines of code during run-time if it calculates a certain value to 'X'?

something like:

 variable_name := variable_name +4;
 if variable_name >1 then
 // END program here and dont execute any lines under this one
 end if

I am not new to programming but new to ADA so finding the correct syntax is a pain. Any help?


Solution

  • There isn’t any specific syntax for this.

    If you are in the main procedure, a simple return will do.

    An Ada83-compatible answer is here on SO.

    Both those are OK so long as you don’t have any tasks.

    There’s an Ada95 Rosetta Code solution, which will work whether you have tasks or not:

    with Ada.Task_Identification;  use Ada.Task_Identification;
    
    procedure Main is
       -- Create as many task objects as your program needs
    begin
       -- whatever logic is required in your Main procedure
       if some_condition then
          Abort_Task (Current_Task);
       end if;
    end Main;
    

    and a GNAT-specific solution, also OK with tasks:

    with Ada.Text_IO; use Ada.Text_IO;
    with GNAT.OS_Lib;
    procedure Stopping is
       procedure P is
       begin
          GNAT.OS_Lib.OS_Exit (0);
       end P;
    begin
       Put_Line ("starting");
       P;
       Put_Line ("shouldn't have got here");
    end Stopping;