Re: Global Varibles!!

[dewar@merv.cs.nyu.edu (Robert Dewar)]

Norman said

<< package Serial_Numbers is
   procedure Get_Next (Number: out Natural);
end Serial_Numbers;

package body Serial_Numbers is
   Next: Natural := 0:
   procedure Get_Next (Number: out Natural) is
   begin
      Number := Next;
      if Number = Natural'Last then
         Number := 0;
      else
         Number := Number + 1;
      end if;
   end Get_Next;
end Serial_Numbers;
>>

Of course in general this kind of hiding is quite appropriate. Note however
a danger, here we have an unexposed global variable that is not protected
against task switches. If the global is in the spec, you are at least
clearly publishing a warning that you have an unprotected global.