Re: Ada 0x Wish List

[cts@kampong.aedinc.net ((null))]

In article <RKIh6.3190$j45.247550@e3500-chi1.usenetserver.com>,
Peter Richtmyer <pmr@efortress.com> wrote:
>
>2) In a subroutine, would like to be able to declare variables that are
>"persistent", like C "static" variables and only used by the one subroutine.
>Presently this data must be in the package body (or spec, or some other
>package spec), where it is visible and updatable by other routines,
>even though it is intended for use by one routine only. (Or is there
>another easy way to do this already?)


Just wrap the subroutine in a sub-package.  It does require a bit
more typing (~7 more lines of code) but my typing is getting better
everyday. :-)


--- foo.ads
package Foo is 
   procedure Do_Stuff;
   function Baz return Integer;
end Foo;


--- foo.adb
with Ada.Text_IO; use Ada.Text_IO;

package body Foo is 
   
   package Bar is 
      function Baz return Integer;
   private
      -- The variable I in this subpackage 
      -- will 'remember' it's value between calls 
      -- to Baz.  
      I: Integer := 0;
   end Bar;
   package body Bar is 
      function Baz return Integer is 
      begin
         I := I+3;
         return I;
      end Baz;
   end Bar;
   function Baz return Integer renames Bar.Baz;
   
   procedure Do_Stuff is 
   begin
      Put_Line("baz returned " & Integer'Image(Baz));
      for I in 1..10 loop
         Put_Line("I is " & Integer'Image(I) 
                  & " and baz returned " & Integer'Image(Baz));
      end loop;
   end run;
end Foo;

      

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