Re: RFC: Prototype for a user threading library in Ada

[rieachus@comcast.net]

I don't get it.  If this is your "motivation":

> The motivation is a two-liner. Let you have some consumer of data: 
>
>    procedure Write (Buffer : String; Last : out Integer); 
>
> It may take less than the whole string when called, but will take more 
> data later. So, the parameter Last. Now you want to write a program in a 
> *normal* way: 
>
>    Write ("This"); 
>    Write ("That"); 
>
> That's it. 

You may want to make your Last parameter in or in out, but that's a detail.

The common Ada idiom is:

   procedure Write (S: in String) is
      Blanks: constant Buffer := (others := ' ');
   -- I assume that their are constant size buffers around somewhere we are
   -- matching.
      SS: String(1..S'Length) := S;
   begin
     Write(S & Blanks(Buffer(SS'Length+1..Blanks'Last), SS'Length);
   end Write;
   -- SS is just belt and suspenders in case S has unusual bounds. 

Put this in the right place, and your calls above will call your Write procedure.  Of course, most Ada IO doesn't require padding. (That is what Unconstrained_Strings are for.) But if you have a low-level routine that needs, padding, for example a protected object that has a procedure with a fixed buffer size? No big deal.

And don't worry about the constant Blanks.  Assuming it is a reasonable size, your compiler should put it in the executable somewhere.  (If it doesn't, move it to a library package.)

Little routines like this are what makes Ada.Text_IO comfortable, if you really have to use it.