Re: Q: Line_IO

["Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de>]

On Mon, 31 Aug 2009 00:59:38 +0200, Georg Bauhaus wrote:

> Text_IO seems fairly slow when just reading lines of text.
> Here are two alternative I/O subprograms for Line I/O, in plain Ada,
> based on Stream_IO.   They seem to run significantly faster.

When you print you do:

   Stream_IO.Write (Stdout, To_Bytes (Item & Separator_Sequence));

You could try not to concatenate:

   Stream_IO.Write (Stdout, To_Bytes (Item));
   Stream_IO.Write (Stdout, To_Bytes (Separator_Sequence));

, which should be faster when Item is large.

Then there is a crazy way to convert congruent types without
Unchecked_Conversion. I cannot tell whether it is actually faster:

   procedure Print (Item : String) is
      subtype Index is Stream_Element_Offset range 1..Item'Length;
      subtype XBytes is Stream_Element_Array (Index);
      Alias : XBytes;
      for Alias'Address use Item'Address;
   begin
      Stream_IO.Write (Stdout, Alias);
      ...   

P.S. The superimposed object shall not have initializers.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de